Reduction of nuclear Y654-p-ß-catenin expression through SH3GL2-meditated downregulation of EGFR in chemotolerance TNBC: Clinical and prognostic importance.

Triple negative breast cancer (TNBC) originates from a less differentiated ductal cell of breast, which is less sensitive to chemotherapy. The chemotolerance mechanism of TNBC has not yet been studied in detail. For this reason, molecular profiles (expression/genetic/epigenetic) of Y654-p-ß-catenin (active) and its kinase epidermal growth factor receptor (EGFR) along with SH3GL2 (regulator of EGFR homeostasis) were compared between neoadjuvant chemotherapy treated (NACT) and pretherapeutic TNBC samples. Reduced nuclear expression of Y654-p-ß-catenin protein with low proliferation index and CD44 prevalence showed concordance with reduced expression of EGFR/Y1045-p-EGFR proteins in the NACT samples than the pretherapeutic TNBC samples. Infrequent messenger RNA expression, gene amplification (10-32.5%), and mutation (1%) of EGFR were seen in the TNBC samples irrespective of therapy, suggesting the importance of EGFR protein stabilization in this tumor. The upregulation of SH3GL2 seen in the NACT samples in contrast to the pretherapeutic samples might be due to its promoter hypomethylation, as seen in the quantitative methylation assay. A similar trend of upregulation of SH3GL2 and downregulation of EGFR, Y1045-p-EGFR, Y654-p-ß-catenin were seen in the MDA-MB-231 cell line using antharacycline antitumor drugs (doxorubicin/nogalamycin). The NACT patients with reduced expression of Y654-p-ß-catenin and/or EGFR and high expression of SH3GL2 showed comparatively better prognosis than the pretherapeutic patients. Thus, our study showed that reduced nuclear expression of Y654-p-ß-catenin in NACT samples due to downregulation of EGFR protein through promoter hypomethylation-mediated upregulation of SH3GL2, resulting in low proliferation index/CD44 prevalence with better prognosis of the NACT patients, might have an important role in the chemotolerance of TNBC.

Epigallocatechin gallate in combination with eugenol or amarogentin shows synergistic chemotherapeutic potential in cervical cancer cell line.

In this study, antitumor activity of epigallocatechin gallate (EGCG; major component of green tea polyphenol), eugenol (active component of clove), and amarogentin (active component of chirata plant) either alone or in combination were evaluated in Hela cell line. It was evident that EGCG with eugenol-amrogentin could highly inhibit the cellular proliferation and colony formation than individual treatments. Induction of apoptosis was also higher after treatment with EGCG in combination with eugenol-amrogentin than individual compound treatments. The antiproliferative effect of these compounds was due to downregulation of cyclinD1 and upregulation of cell cycle inhibitors LIMD1, RBSP3, and p16 at G1/S phase of cell cycle. Treatment of these compounds could induce promoter hypomethylation of LimD1 and P16 genes as a result of reduced expression of DNA methyltransferase 1 (DNMT1). Thus, our study indicated the better chemotherapeutic effect of EGCG in combination with eugenol-amarogentin in Hela cell line. The chemotherapeutic effect might be due to the epigenetic modification particularly DNA hypomethylation through downregulation of DNMT1.

Landscape of toll-like receptors expression in tumor microenvironment of triple negative breast cancer (TNBC): Distinct roles of TLR4 and TLR8.

TNBC is the most aggressive and hormone receptor-negative subtype of breast cancer with molecular heterogeneity in bulk tumors hindering effective treatment. Toll-like receptors (TLRs) have the potential to ignite diverse immune responses in the tumor microenvironment (TME). This encouraged us to screen their transcript expression in the publically available TCGA datasets. Reported molecular subtypes of TNBC may represent different TMEs and we observed differentially expressed TLRs (DETs) i.e. TLR3/4/6/8/9 have unique expression pattern in the TNBC subtypes, particularly in Immunomodulatory (IM) TNBC subtype. We then dissected expression of the DETs in immune and other components of the TME. TLR4 and TLR8 showed significant (p-value ≤ 0.05) negative partial correlation with tumor purity compared to other DETs. Interestingly, TLR4 and TLR8 expression showed a significant (adjusted p-value ≤ 0.05) correlation with different subsets of immune infiltrating cells having the highest correlation with monocytes/macrophage/dendritic cell populations mediating both innate and adaptive response in TNBC. The co-expression network identified genes correlated with these immune cells. Further, GSEA analysis of co-expressed genes showed a significant association of TLR8 partners with 'Peptide ligand binding', 'Gά-signaling', and 'Cytokine-cytokine interaction' while TLR4 associated genes correlated with 'Adaptive immune system' and 'Systemic lupus erythematosus' interactome. Finally, the expression of TLR4 protein was validated in a panel of TNBC cell lines. TLR4 expression in chemoresponsive TNBC was also validated in TNBC cell lines upon Paclitaxel (PTX) treatment. Collectively, the present study identified specific DETs in TNBC and discovered a prospective role of TLR4 and TLR8 in the maintenance of tumor-immune-microenvironment.

Frequent deletion and methylation in SH3GL2 and CDKN2A loci are associated with early- and late-onset breast carcinoma.

BACKGROUND: This study attempts to understand the association of candidate tumour suppressor genes SH3GL2, CDKN2A (p16-p14) and CDKN2B (p15) in development of early-onset (group A) and late-onset (group B) breast carcinoma (BC). METHODS: Deletion, methylation, and mutation of the candidate tumour suppressor genes (TSGs) were analysed in 47 group A and 59 group B samples. Immunohistochemical analysis was used to identify the expression status of SH3GL2 and p16. Clinicopathological correlation of the alterations was analysed by the chi-square and log-rank tests. RESULTS: Higher frequency of overall alterations (46-62%) in SH3GL2 and p16-p14 than p15 (22-26%) indicated their importance in BC. Deletion frequencies were in the following order: group A: p14 (43%) > p16 (42%) > SH3GL2 (38%) > p15 (33%) and group B: p14 (36%) > p16 (33%) > SH3GL2 (31%) > p15 (14%) while, methylation frequencies were: group A: SH3GL2 (34%) > p16 (28%) > p14 (26%) > p15 (15%) and group B: SH3GL2 (36%) > p16 (31%) > p14 (29%) > p15 (15%). Infrequent mutation was observed only in CDKN2A common exon-2. Immunohistochemical analysis showed significant association between expression of SH3GL2 and p16 with their deletion (P = 0.01 and 0.02, respectively) and methylation status (P = 0.007 and 0.01, respectively). In group A, overall alterations of SH3GL2 showed significant association with CDKN2A locus with significant prognostic implications, whereas CDKN2A and CDKN2B loci were associated in both groups. CONCLUSIONS: The molecular mechanisms involving CDKN2A inactivation seem to follow similar pathway in the pathogenesis of both age groups of BC while significant association of SH3GL2 with CDKN2A might play a synergistic role in the development of group A.