While studying on epigenetic regulatory mechanisms (DNA methylation at C-5 of -CpG- cytosine and demethylation of methylated DNA) of certain genes (FAS, CLU, E-cadh, CD44, and Cav-1) associated with prostate cancer development and its better management, we noticed that the used in vivo dose of 5-aza-2'-deoxycytidine (5.0 to 10.0 nM, sufficient to inhibit DNA methyltransferase activity in vitro) helped in the transcription of various genes with known (steroid receptors, AR and ER; ER variants, CD44, CDH1, BRCA1, TGFβR1, MMP3, MMP9, and UPA) and unknown (DAZ and Y-chromosome specific) proteins and the respective cells remained healthy in culture. At a moderate dose (20 to 200 nM) of the inhibitor, cells remain growth arrested. Upon subsequent challenge with increased dose (0.5 to 5.0 μM) of the inhibitor, we observed that the cellular morphology was changing and led to death of the cells with progress of time. Analyses of DNA and anti-, pro-, and apoptotic factors of the affected cells revealed that the molecular events that went on are characteristics of programmed cell death (apoptosis).

Loss of heterozygosity (LOH) in 16q appears in ~20-30% cases of Wilms' tumor. Within this region, known as common fragile site FRA16D, the WWOX tumor suppressor gene is located. Abnormalities of WWOX gene expression levels were observed in many tumor types and were associated with worse prognosis. The purpose of this study was to investigate the role of the WWOX tumor suppressor gene in Wilms' tumor samples. We evaluated the correlation between expression of WWOX and genes involved in proliferation (Ki67), apoptosis (BCL2, BAX), signal transduction (ERBB4, ERBB2, EGFR), cell cycle (CCNE1, CCND1), cell adhesion (CDH1) and transcription (TP73) using real-time RT-PCR in 23 tumor samples. We also analyzed the potential causes of WWOX gene expression reduction i.e., promoter methylation status (MethylScreen method) and loss of heterozygosity (LOH) status. We revealed a positive correlation between WWOX expression and BCL2, BCL2/BAX ratio, EGFR, ERBB4 isoform JM-a, TP73 and negative correlation with both cyclins. Loss of heterozygosity of the WWOX gene was observed only at intron 8, however, it had no influence on the reduction of its expression levels. Contrary to LOH, methylation of the region covering the 3' end of the promoter and part of exon 1 was associated with statistically significant reduction of WWOX gene expression levels. In the present study we reveal that in Wilms' tumors the WWOX expression levels are positively associated with the process of apoptosis, signal transduction through the ErbB4 pathway and EGFR and negatively with the regulation of the cell cycle (by cyclin E1 and D1). Moreover, our analysis indicates that in this type of tumor the expression of the WWOX gene can be regulated by an epigenetic mechanism--its promoter methylation.

BACKGROUND

Gene panel testing for breast cancer susceptibility has become relatively cheap and accessible. However, the breast cancer risks associated with mutations in many genes included in these panels are unknown.

METHODS

We performed custom-designed targeted sequencing covering the coding exons of 17 known and putative breast cancer susceptibility genes in 660 non-BRCA1/2 women with familial breast cancer. Putative deleterious mutations were genotyped in relevant family members to assess co-segregation of each variant with disease. We used maximum likelihood models to estimate the breast cancer risks associated with mutations in each of the genes.

RESULTS

We found 31 putative deleterious mutations in 7 known breast cancer susceptibility genes (TP53, PALB2, ATM, CHEK2, CDH1, PTEN and STK11) in 45 cases, and 22 potential deleterious mutations in 31 cases in 8 other genes (BARD1, BRIP1, MRE11, NBN, RAD50, RAD51C, RAD51D and CDK4). The relevant variants were then genotyped in 558 family members. Assuming a constant relative risk of breast cancer across age groups, only variants in CDH1, CHEK2, PALB2 and TP53 showed evidence of a significantly increased risk of breast cancer, with some supportive evidence that mutations in ATM confer moderate risk.

CONCLUSIONS

Panel testing for these breast cancer families provided additional relevant clinical information for <2% of families. We demonstrated that segregation analysis has some potential to help estimate the breast cancer risks associated with mutations in breast cancer susceptibility genes, but very large case-control sequencing studies and/or larger family-based studies will be needed to define the risks more accurately.

Aberrant DNA methylation has been observed in cervical cancer; however, most studies have used non-quantitative approaches to measure DNA methylation. The objective of this study was to quantify methylation within a select panel of genes previously identified as targets for epigenetic silencing in cervical cancer and to identify genes with elevated methylation that can distinguish cancer from normal cervical tissues. We identified 49 women with invasive squamous cell cancer of the cervix and 22 women with normal cytology specimens. Bisulfite-modified genomic DNA was amplified and quantitative pyrosequencing completed for 10 genes (APC, CCNA, <em>CDH1</em>, <em>CDH1</em>3, WIF1, TIMP3, DAPK1, RARB, FHIT, and SLIT2). A Methylation Index was calculated as the mean percent methylation across all CpG sites analyzed per gene (~4-9 CpG site) per sequence. A binary cut-point was defined at >15% methylation. Sensitivity, specificity and area under ROC curve (AUC) of methylation in individual genes or a panel was examined. The median methylation index was significantly higher in cases compared to controls in 8 genes, whereas there was no difference in median methylation for 2 genes. Compared to HPV and age, the combination of DNA methylation level of DAPK1, SLIT2, WIF1 and RARB with HPV and age significantly improved the AUC from 0.79 to 0.99 (95% CI: 0.97-1.00, p-value = 0.003). Pyrosequencing analysis confirmed that several genes are common targets for aberrant methylation in cervical cancer and DNA methylation level of four genes appears to increase specificity to identify cancer compared to HPV detection alone. Alterations in DNA methylation of specific genes in cervical cancers, such as DAPK1, RARB, WIF1, and SLIT2, may also occur early in cervical carcinogenesis and should be evaluated.

Multi-gene panels are used to identify genetic causes of hereditary breast and ovarian cancer (HBOC) in large patient cohorts. This study compares the diagnostic workflow in two centers and gives valuable insights into different next-generation sequencing (NGS) strategies. Moreover, we present data from 620 patients sequenced at both centers. Both sequencing centers are part of the German consortium for hereditary breast and ovarian cancer (GC-HBOC). All 620 patients included in this study were selected following standard BRCA1/2 testing guidelines. A set of 10 sequenced genes was analyzed per patient. Twelve samples were exchanged and sequenced at both centers. NGS results were highly concordant in 12 exchanged samples (205/206 variants = 99.51 %). One non-pathogenic variant was missed at center B due to a sequencing gap (no technical coverage). The custom enrichment at center B was optimized during this study; for example, the average number of missing bases was reduced by a factor of four (vers. 1: 1939.41, vers. 4: 506.01 bp). There were no sequencing gaps at center A, but four CCDS exons were not included in the enrichment. Pathogenic mutations were found in 12.10 % (75/620) of all patients: 4.84 % (30/620) in BRCA1, 4.35 % in BRCA2 (27/620), 0.97 % in CHEK2 (6/620), 0.65 % in ATM (4/620), 0.48 % in CDH1 (3/620), 0.32 % in PALB2 (2/620), 0.32 % in NBN (2/620), and 0.16 % in TP53 (1/620). NGS diagnostics for HBOC-related genes is robust, cost effective, and the method of choice for genetic testing in large cohorts. Adding 8 genes to standard BRCA1- and BRCA2-testing increased the mutation detection rate by one-third.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal malignancies. Given that macroautophagy/autophagy activation is prevalent in PDAC, the dual roles of autophagy could be involved in PDAC heterogeneity. In this work, we demonstrated that TGFB1 induced autophagic flux through SMAD4-dependent or SMAD4-independent pathways based on a distinct genetic context. In SMAD4-positive PDAC cells, TGFB1-induced autophagy promoted proliferation and inhibited migration by decreasing the nuclear translocation of SMAD4. Conversely, TGFB1-induced autophagy inhibited proliferation and promoted migration in SMAD4-negative cells through the regulation of MAPK/ERK activation. TGFB1 expression also positively correlated with LC3B expression in PDAC specimens. A high level of LC3B was associated with unfavorable overall survival (OS) and disease-free survival (DFS) in SMAD4-negative PDAC patients, although LC3B could not predict OS and DFS for the 110 PDAC patients. Thus, TGFB1-induced autophagy contributed to the different patterns of PDAC progression. This knowledge can aid in improving our understanding of the molecular classification of PDAC and might guide the development of therapeutic strategies for PDAC, especially for SMAD4-negative PDAC. Abbreviations: CDH1: cadherin 1; CDH2: cadherin 2; CI: combination index; CQ: chloroquine; DFS: disease-free survival; EMT: epithelial-to-mesenchymal transition; ERK: extracellular signal-regulated protein kinase; GFP: green fluorescent protein; IHC: immunohistochemistry; MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAPK: mitogen-activated protein kinase; OS: overall survival; PBS: phosphate-buffered saline; PDAC: pancreatic ductal adenocarcinoma; RAP: rapamycin; RFP: red fluorescent protein; RT: room temperature; shRNA: short-hairpin RNA; SQSTM1: sequestosome 1; TCGA: The Cancer Genome Atlas; TEM: transmission electron microscopy; TGFB1: transforming growth factor beta 1; TMA: tissue microarray.

SNAI1, SNAI2, and SNAI3 genes, encoding transcriptional repressors implicated in epithelial mesenchymal transition (EMT), are human homologs of Drosophila snail (sna) and slug genes. SNAI1 represses transcription of CDH1 (E-cadherin) gene. SNAI2 induces the first phase of EMT, including desmosome dissociation, cell spreading, and initiation of cell separation. Because SNAI family proteins are implicated in EMT during embryogenesis and carcinogenesis, SNAI family genes are potent targets of pharmacogenomics. Here, comparative genomics analyses and comparative proteomics analyses on SNAI family orthologs were performed. Rat Snai3 gene, consisting of three exons, was identified within rat genome sequence AC111791.4. Zebrafish snai1a (NM_131066.1) was identified as SNAI1 ortholog. Chicken ChEST362l17 (CR407272.1), Xenopus slug (AF368041.1), and zebrafish zgc92564 (NM_001008581.1) were identified as SNAI2 orthologs. Chicken snail (NM_ 205142.1), Xenopus snail (BC056857.1), and zebrafish snai1b (NM_130989.1) were identified as SNAI3 orthologs. SNAI1 orthologs consisted of SNAG domain and four zinc finger (ZNF) domains, while SNAI2 and SNAI3 orthologs consisted of SNAG domain and five ZNF domains. Based on the integromics analyses, SNAI2 orthologs were found to be more conserved than SNAI1 and SNAI3 orthologs. SNAI1 mRNA was expressed in placenta, neuroblastoma, and diffuse type gastric cancer. SNAI2 mRNA was expressed in placenta, melanocyte, embryonic stem (ES) cells, leiomyosarcoma, neuroblastoma, and glioblastoma. SNAI3 mRNA was expressed in B cells. Expression of SNAI3 mRNA was repressed due to the existence of anti-sense single-exon transcript. SNAI1, functioning as E-cadherin repressor, is implicated in the malignant infiltrating phenotype of diffuse type gastric cancer through the induction of EMT or fibroblastoid transformation.

BACKGROUND

Promoter hypermethylation of tumor suppressor genes is one of the major events in gastric carcinogenesis. Promoter hypermethylation is also present in non-neoplastic gastric epithelium as age-related phenomenon and some reports suggest the potential association between promoter hypermethylation and Helicobacter pylori infection. Here, we examined whether methylation of multiple promoter CpG islands would occur by H. pylori infection and correlate with histological or serological severity of chronic gastritis.

METHODS

One hundred and ninety-one gastric mucosa samples were obtained by endoscopy. The promoter methylation status of the p14, p16, DAP-kinase and CDH1 genes were determined by methylation-specific-polymerase chain reaction. The degree of gastritis in the antrum was assessed according to the updated Sydney system in 150 participants. The pepsinogen (PG) I/II ratio was calculated based on the data of serum PG I and PG II levels measured by radioimmunoassay in 54 selected cases.

RESULTS

CpG island methylation was found in 32.5% for p14, 35.1% for p16, 43.5% for DAP-kinase and 36.1% for CDH1, whereas non, 1, 2, 3, and all methylation of four promoter CpG sites were present in 46 (24.1%), 59 (30.9%), 46 (24.1%), 30 (15.7%), and 10 (5.2%) participants, respectively. A strong association between the increased number of methylated CpG islands and H. pylori infection was observed (P<0.0001). An increased number of methylated CpG islands was also associated with severity of neutrophil infiltration (P<0.0001), mononuclear cell infiltration (P<0.0001) and atrophy (P=0.0021) in all, and severity of neutrophil infiltration (P=0.0177) and mononuclear cell infiltration (P=0.0004) in H. pylori-positive participants. An increased number of methylated CpG islands correlated with lower PG I/II ratio in all (P=0.0105) and H. pylori-infected participants (P=0.074).

CONCLUSIONS

Multiple promoter CpG islands would be methylated by H. pylori infection, and an increased number of methylated CpG sites correlate with histological and serological severity of chronic gastritis.

The role of E-cadherin in Hereditary Diffuse Gastric Cancer (HDGC) is unequivocal. Germline alterations in its encoding gene (CDH1) are causative of HDGC and occur in about 40% of patients. Importantly, while in most cases CDH1 alterations result in the complete loss of E-cadherin associated with a well-established clinical impact, in about 20% of cases the mutations are of the missense type. The latter are of particular concern in terms of genetic counselling and clinical management, as the effect of the sequence variants in E-cadherin function is not predictable. If a deleterious variant is identified, prophylactic surgery could be recommended. Therefore, over the last few years, intensive research has focused on evaluating the functional consequences of CDH1 missense variants and in assessing E-cadherin pathogenicity. In that context, our group has contributed to better characterize CDH1 germline missense variants and is now considered a worldwide reference centre. In this review, we highlight the state of the art methodologies to categorize CDH1 variants, as neutral or deleterious. This information is subsequently integrated with clinical data for genetic counseling and management of CDH1 variant carriers.

Cancer stem cells (CSCs) are considered to be the origin of cancer relapse and metastasis. The better understanding of CSCs, including CSCs in human colorectal cancer (CRC), may facilitate prevention and treatment. This study aimed to establish a CSC enrichment model via the induction of epithelial-mesenchymal transition (EMT) in CRC cells. We established an EMT model using the SW480 CRC cell line by CDH1 knockdown using shRNA interference. CD24+CD44+ cells were enriched in the CDH1 knockdown cells. The cells exhibited mesenchymal morphology and expressed high levels of EMT-related proteins, which confirmed that these cells had undergone EMT. Our results further showed that the proliferation rate of the transfected cells was reduced, whereas their colony-forming capacity and tumorigenesis in vivo was significantly enhanced compared to the control cells. In conclusion, these cells were highly enriched CSCs (compared to normal CSCs) and may be used as a stable model for cancer research and anticancer drug screening.

The anaphase-promoting complex/cyclosome (APC/C) is a massive E3 ligase that controls mitosis by catalyzing ubiquitination of key cell cycle regulatory proteins. The APC/C assembly contains two subcomplexes: the "Platform" centers around a cullin-RING-like E3 ligase catalytic core; the "Arc Lamp" is a hub that mediates transient association with regulators and ubiquitination substrates. The Arc Lamp contains the small subunits APC16, CDC26, and APC13, and tetratricopeptide repeat (TPR) proteins (APC7, APC3, APC6, and APC8) that homodimerize and stack with quasi-2-fold symmetry. Within the APC/C complex, APC3 serves as center for regulation. APC3's TPR motifs recruit substrate-binding coactivators, CDC20 and CDH1, via their C-terminal conserved Ile-Arg (IR) tail sequences. Human APC3 also binds APC16 and APC7 and contains a >200-residue loop that is heavily phosphorylated during mitosis, although the basis for APC3 interactions and whether loop phosphorylation is required for ubiquitination are unclear. Here, we map the basis for human APC3 assembly with APC16 and APC7, report crystal structures of APC3Δloop alone and in complex with the C-terminal domain of APC16, and test roles of APC3's loop and IR tail binding surfaces in APC/C-catalyzed ubiquitination. The structures show how one APC16 binds asymmetrically to the symmetric APC3 dimer and, together with biochemistry and prior data, explain how APC16 recruits APC7 to APC3, show how APC3's C-terminal domain is rearranged in the full APC/C assembly, and visualize residues in the IR tail binding cleft important for coactivator-dependent ubiquitination. Overall, the results provide insights into assembly, regulation, and interactions of TPR proteins and the APC/C.

Human SNAIL1 (SNAI1) protein encoded by SNAI1/SNA gene represses transcription of E-cadherin/CDH1 gene. Human SNAIL2 (SNAI2) protein encoded by SNAI2/SLUG gene induces the first phase of epithelial-mesenchymal transition (EMT), including desmosome dissociation, cell spreading, and initiation of cell separation. Here, we have identified human SNAIL3 (SNAI3) gene using bioinformatics. Human SNAI3 gene, consisting of at least three exons, spans around the nucleotide position 320214-328221 of human reference genomic contig NT_010404.8 in the reverse orientation. SNAI3 gene, was located between KIAA0233 gene and CBFA2T3 gene in human chromosome 16q24.3, a region affected in breast cancer, gastric cancer, hepatocellular carcinoma, ovarian cancer, and therapy-related myeloid leukemia with t(16;21)(q24;q22) translocation. Human SNAI3 gene was found to encode 292-amino-acid polypeptide with the N-terminal SNAG domain and five zinc finger domains. N-terminal SNAG domain was identified in zinc finger proteins SNAI1, SNAI2, SNAI3, SCRATCH (SCRT1), GFI1, and GFI1B. ATP/GTP binding site was identified in SCRT1, GFI1 and GFI1B, but not in SNAI1, SNAI2 and SNAI3. Phylogenetic analysis of human zinc finger proteins with SNAG domain revealed that SNAI1, SNAI2 and SNAI3 were more closely related. These results clearly indicate that SNAI1, SNAI2 and SNAI3 constitute a subfamily among SNAG zinc-finger proteins. Human SNAI3 mRNA was expressed in skin melanotic melanoma, lung epidermoid carcinoma, and germ cell tumor. Because SNAG zinc-finger proteins are transcriptional repressors implicated in carcinogenesis and embryogenesis, SNAI3 gene might be a potent target of pharmacogenomics in the field of oncology and regenerative medicine.

We examined the expression and hormonal regulation of E-cadherin (CDH1) and N-cadherin (CDH2) with respect to primordial follicle formation. Hamster Cdh1 and Cdh2 cDNA and amino acid sequences were more than 90% similar to those of the mouse, rat, and human. Although CDH1 expression remained exclusively in the oocytes during neonatal ovary development, CDH2 expression shifted from the oocytes to granulosa cells of primordial follicles on postnatal day (P)8. Subsequently, strong CDH2 expression was restricted to granulosa cells of growing follicles. Cdh2 mRNA levels in the ovary decreased from embryonic d 13 through P10 with a transient increase on P7, which was the day before the appearance of primordial follicles. Cdh1 mRNA levels decreased from embryonic d 13 through P3 and then showed a transient increase on P8, coinciding with the formation of primordial follicles. CDH1 and CDH2 expression were consistent with that of mRNA. Neutralization of FSH in utero impaired primordial follicle formation with an associated decrease in Cdh2 mRNA and CDH2, but an increase in Cdh1 mRNA and CDH1 expression. The altered expression was reversed by equine chorionic gonadotropin treatment on P1. Whereas a CDH2 antibody significantly reduced the formation of primordial and primary follicles in vitro, a CDH1 antibody had the opposite effect. This is the first evidence to suggest that primordial follicle formation requires a differential spatiotemporal expression and action of CDH1 and CDH2. Further, FSH regulation of primordial follicle formation may involve the action of CDH1 and CDH2.

Malignant peripheral nerve sheath tumors (MPNSTs) are highly malignant tumors affecting adolescents and adults. There have been a few reports on chromosomal aberrations of MPNSTs; however, the tumor-specific alteration remains unknown. We characterized the genomic alterations in 8 MPNSTs and 8 schwannomas by metaphase comparative genomic hybridization (CGH). In 5 of 8 MPNSTs, microarray CGH was added for more detailed analyses. Frequent gains were identified on 3q13-26, 5p13-14, and 12q11-23 and frequent losses were at 1p31, 10p, 11q24-qter, 16, and 17. Microarray CGH revealed frequent gains of EGFR, DAB2, MSH2, KCNK12, DDX15, CDK6, and LAMA3, and losses of CDH1, GLTSCR2, EGR1, CTSB, GATA3, and SULT2A1. These genes seem to be responsible for developing MPNSTs. The concordance rate between metaphase CGH and microarray CGH was 66%. Metaphase CGH was useful for identifying chromosomal alterations before applying microarray CGH.

BACKGROUND

Heterogeneous nuclear ribonucleoprotein A2B1 (HNRNPA2B1) is closely related to tumour occurrence and development, oncogene expression, apoptosis inhibition and invasion and metastasis capacities. However, its function in the epithelial-mesenchymal transition (EMT) of pancreatic cancer is not fully understood.

METHODS

By comparing various wild-type pancreatic cancer cell lines, we determined which have a higher expression level of HNRNPA2B1 accompanied by the higher expression of N-cadherin and vimentin and lower expression of E-cadherin. Therefore, to elucidate the role of HNRNPA2B1 in EMT, we generated models of HNRNPA2B1 knockdown and overexpression in different types of pancreatic cancer cell lines (MIA Paca-2, PANC-1 and Patu-8988) and examined changes in expression of EMT-related factors, including CDH1, CDH2, vimentin and snail.

RESULTS

The results show that HNRNPA2B1 promotes EMT development by down-regulating E-cadherin and up-regulating N-cadherin and vimentin, and also stimulates the invasion capacity and inhibits viability in human pancreatic cancer cell lines, the similar results in vivo experiments. Moreover, we found that HNRNPA2B1 likely regulates EMT progression in pancreatic carcinoma via the ERK/snail signalling pathway.

CONCLUSIONS

The results of this work suggest that HNRNPA2B1 inhibition has potential antitumour effects, which warrants in-depth investigation.

Degradation of poly-ubiquitinated proteins by the 26S-proteasome complex represents a crucial quantitative control mechanism. The ubiquitin-proteasome system (UPS) plays a pivotal role in the complex molecular network regulating the progression both between and within each cell-cycle phase. Two major complexes are involved: the SKP1-CUL1-F-box-protein complex (SCF) and the anaphase-promoting complex/cyclosome (APC/C). Notwithstanding structural similarities, SCF and APC/C display different cellular functions and mechanisms of action. SCF modulates all cell-cycle stages and plays a prominent role at G1/S transition mainly through three regulatory subunits: Skp2, Fbw7, and beta-TRCP. APC/C, regulated by Cdc20 or Cdh1 subunits, has a crucial role in mitosis. In this review, we will describe how the endothelial cell cycle is regulated by the UPS. We will illustrate the principal SCF- and APC/C-dependent molecular mechanisms that modulate cell growth, allowing a unidirectional cell-cycle progression. Then, we will focus our attention on UPS modulation by oxidative stress, a pathogenic stimulus that causes endothelial dysfunction and is involved in numerous cardiovascular diseases.

Increasing evidence suggests that mechanical factors play a critical role in fate decisions of stem cells. Recently we have demonstrated that a local force applied via Arg-Gly-Asp (RGD) peptides coated magnetic beads to mouse embryonic stem (ES) cells increases cell spreading and cell stiffness and decreases Oct3/4 (Pou5f1) gene expression. However, it is not clear whether the effects of the applied stress on these functions of ES cells can be extended to natural extracellular matrix proteins or cell-cell adhesion molecules. Here we show that a local cyclic shear force applied via fibronectin or laminin to integrin receptors increased cell spreading and stiffness, downregulated Oct3/4 gene expression, and decreased cell proliferation rate. In contrast, the same cyclic force applied via cell-cell adhesion molecule E-cadherin (Cdh1) had no effects on cell spreading, Oct3/4 gene expression, and the self-renewal of mouse ES cells, but induced significant cell stiffening. Our findings demonstrate that biological responses of ES cells to force applied via integrins are different from those to force via E-cadherin, suggesting that mechanical forces might play different roles in different force transduction pathways to shape early embryogenesis.

Cadherins are cell-to-cell adhesion molecules that play an important role in the establishment of adherent-type junctions by mediating calcium-dependent cellular interactions. The CDH1 gene encodes the transmembrane glycoprotein E-cadherin which is important in maintaining homophilic cell-cell adhesion in epithelial tissues. E-cadherin interacts with catenin proteins to maintain tissue architecture. Structural defects or loss of expression of E-cadherin have been reported as a common feature in several human cancer types. This study aimed to evaluate the expression of E-cadherin and their correlation with clinical features in microdissected brain tumor samples from 81 patients, divided into 62 astrocytic tumors grades I to IV and 19 medulloblastomas, and from 5 white matter non-neoplasic brain tissue samples. E-cadherin (CDH1) gene expression was analyzed by quantitative real-time polymerase chain reaction. Mann-Whitney, Kruskal-Wallis, Kaplan-Meir, and log-rank tests were performed for statistical analyses. We observed a decrease in expression among pathological grades of neuroepithelial tumors. Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than did neuroepithelial tumors. Expression of E-cadherin gene was higher in astrocytic than embryonal tumors (P = 0.0168). Low-grade malignancy astrocytomas (grades I-II) showed higher CDH1 expression than did high-grade malignancy astrocytomas (grades III-IV) and medulloblastomas (P < 0.0001). Non-neoplasic brain tissue showed a higher expression level of CDH1 gene than grade I malignancy astrocytomas, considered as benign tumors (P = 0.0473). These results suggest that a decrease in E-cadherin gene expression level in high-grade neuroepithelial tumors may be a hallmark of malignancy in dedifferentiated tumors and that it may be possibly correlated with their progression and dissemination.

Infiltrating lobular breast cancer (ILBC) is the most common special breast cancer subtype. This review provides a comprehensive description of ILBC characteristics, including epidemiology, clinical features, molecular genetics and histomorphology. Twenty detailed supplemental data tables guide through primary data of more than 200 original studies. Meta-analyses indicate that ILBC is at least twice as common in the Western world as it is in other geographic regions. ILBC is over-represented in so-called interval carcinomas and in primary metastatic breast cancer. ILBC is also associated higher age, higher pT stage and hormone receptor (ER/PR) positivity. Pathological complete response rates after neoadjuvant chemotherapy are low, ranging between 0% and 11%. Positive resection margins after breast-conserving surgery are comparatively frequent and 17% to 65% of patients undergo a second surgical intervention. Depending on the morphological stringency in the diagnosis of ILBC, lack of E-cadherin expression is observed in 55% to 100% of cases. CDH1/E-cadherin mutation detection rates vary between 12% and 83%. Various additional molecular factors, including PIK3CA, TP53, FOXA1, FGFR1, ZNF703 and BCAR4, have been implicated in ILBC or progression of lobular carcinoma in situ (LCIS) to invasive cancer and are discussed in detail. Eight instructive figure plates recapitulate the histomorphology of ILBC and its variants. Furthermore, we draw attention to rarely addressed histological details, such as two-sided nuclear compression and fat-avoiding growth at the invasion front. Last but not least, we discuss future translational research directions and emphasize the concept of synthetic lethality, which promises new options for targeted ILBC therapy.

<AbstractText>Gastric cancer (GC) is a leading cause of cancer deaths, and an increased number of GC patients adopt to next-generation sequencing (NGS) to identify tumor genomic alterations for precision medicine.</AbstractText><AbstractText>In this study, we established a hybridization capture-based NGS panel including 612 cancer-associated genes, and collected sequencing data of tumors and matched bloods from 153 gastric cancer patients. We performed comprehensive analysis of these sequencing and clinical data.</AbstractText><AbstractText>35 significantly mutated genes were identified such as TP53, AKAP9, DRD2, PTEN, <em>CDH1</em>, LRP2 et al. Among them, 29 genes were novel significantly mutated genes compared with TCGA study. TP53 is the top frequently mutated gene, and tends to mutate in male (p = 0.025) patients and patients whose tumor located in cardia (p = 0.011). High tumor mutation burden (TMB) gathered in TP53 wild-type tumors (p = 0.045). TMB was also significantly associated with DNA damage repair (DDR) genes genotype (p = 0.047), Lauren classification (p = 1.5e-5), differentiation (1.9e-7), and HER2 status (p = 0.023). 38.31% of gastric cancer patients harbored at least one actionable alteration according to OncoKB database.</AbstractText><AbstractText>We drew a comprehensive mutational landscape of 153 gastric tumors and demonstrated utility of target next-generation sequencing to guide clinical management.</AbstractText>

BACKGROUND

TNBC is an aggressive subset of breast cancer (BC) without specific target therapy.

METHODS

This observational, retrospective study included 45 cases of TNBC. The aim of this study was to evaluate the expression of the AR, E-cadherin and Ki-67 in relation to histological type, time to relapse and overall survival (OS). Immunohistochemistry (IHC) was carried out on formalin-fixed paraffin-embedded tumor samples obtained from patients defined TNBC.

RESULTS

The AR was positive (IHC >10%) in 26.6%. E-cadherin (CDH1) expression was considered positive if the score was ≥ 2. This expression was negative in 53.3% cases. The Ki-67 index was ≥ 20% in 37.7%. Univariate analyses showed that AR, CDH1 and Ki-67 are significantly associated with OS. Multivariate analysis showed that AR and Ki-67 expression are independent variables associated with OS. The statistical analysis showed that patients with AR negative and Ki-67 positive expression have a significant correlation with poor outcome.

CONCLUSIONS

Our data suggest that the combination of AR and E-cadherin expression as well as Ki-67 status might be useful prognostic markers in TNBC. Hence, these molecular determinants could play an interesting role to classify subgroups of TNBC.

Changes in the pattern of DNA methylation are among the most common alterations observed in human cancers, such as gastric carcinomas. We analysed in a series of 51 sporadic gastric carcinomas the methylation status of the promoter regions of the hMLH1, CDH1, MGMT and COX2 genes. We aimed to determine the frequency of CpG island hypermethylation and to find out whether the occurrence of concurrent hypermethylation is related to the clinicopathological features of the gastric carcinomas. Using methylation-sensitive restriction analysis/polymerase chain reaction (PCR) and methylation-specific PCR (MSP) strategies, we searched for the presence of hypermethylation on the promoter region of the 4 selected genes. All showed hypermethylation of their promoter regions with frequencies of 37, 51, 61 and 29% for hMLH1, CDH1, MGMT and COX2, respectively. Concurrent hypermethylation was more frequently observed in MSI-H (P=0.0005) and diploid (P=0.029) tumours. Hypermethylation of hMLH1 was associated with MSI-H tumours (P=0.0001), whereas hypermethylation of MGMT was associated with MSI-H (p=0.021) and diploid tumours (p=0.012). Our results indicate that concurrent hypermethylation is a common event in gastric cancer, suggesting that global methylation changes play an important role in the development of sporadic gastric carcinoma. Moreover, inactivation of different gene promoters by hypermethylation is significantly associated with microsatellite instability (MSI-H) and diploidy: hMLH1 determines MSI-H and MGMT the diploid status of gastric carcinomas.

Adenovirus E4orf4 (early region 4 open reading frame 4) protein induces protein phosphatase 2A-dependent non-classical apoptosis in mammalian cells and irreversible growth arrest in Saccharomyces cerevisiae. Oncogenic transformation sensitizes cells to E4orf4-induced cell death. To uncover additional components of the E4orf4 network required for induction of its unique mode of apoptosis, we used yeast genetics to select gene deletions conferring resistance to E4orf4. Deletion of YND1, encoding a yeast Golgi apyrase, conferred partial resistance to E4orf4. However, Ynd1p apyrase activity was not required for E4orf4-induced toxicity. Ynd1p and Cdc55p, the yeast protein phosphatase 2A-B subunit, contributed additively to E4orf4-induced toxicity. Furthermore, concomitant overexpression of one and deletion of the other was detrimental to yeast growth, demonstrating a functional interaction between the two proteins. YND1 and CDC55 also interacted genetically with CDC20 and CDH1/HCT1, encoding activating subunits of the anaphase-promoting complex/cyclosome. In addition to their functional interaction, Ynd1p and Cdc55p interacted physically, and this interaction was disrupted by E4orf4, which remained associated with both proteins. The results suggested that Ynd1p and Cdc55p share a common downstream target whose balanced modulation by the two E4orf4 partners is crucial to viability. Disruption of this balance by E4orf4 may lead to cell death. NTPDase-4/Lalp70/UDPase, the closest mammalian homologue of Ynd1p, associated with E4orf4 in mammalian cells, suggesting that the results in yeast are relevant to the mammalian system.

Calpains regulate a wide spectrum of biological functions, including migration, adhesion, apoptosis, secretion, and autophagy, through the modulating cleavage of specific substrates. Ubiquitous microcalpain (μ-calpain) and millicalpain (m-calpain) are heterodimers composed of catalytic subunits encoded, respectively, by CAPN1 and CAPN2 and a regulatory subunit encoded by CAPNS1. Here we show that calpain is required for the stability of the deubiquitinating enzyme USP1 in several cell lines. USP1 modulates DNA replication polymerase choice and repair by deubiquitinating PCNA. The ubiquitinated form of the USP1 substrate PCNA is stabilized in CAPNS1-depleted U2OS cells and mouse embryonic fibroblasts (MEFs), favoring polymerase-η loading on chromatin and increased mutagenesis. USP1 degradation directed by the cell cycle regulator APC/C(cdh1), which marks USP1 for destruction in the G1 phase, is upregulated in CAPNS1-depleted cells. USP1 stability can be rescued upon forced expression of calpain-activated Cdk5/p25, previously reported as a cdh1 repressor. These data suggest that calpain stabilizes USP1 by activating Cdk5, which in turn inhibits cdh1 and, consequently, USP1 degradation. Altogether these findings point to a connection between the calpain system and the ubiquitin pathway in the regulation of DNA damage response and place calpain at the interface between cell cycle modulation and DNA repair.