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The article in the Clinical & Translational Medicine journal discusses a study on targeting CBP to reverse chemoresistance in CDX2/REG4 double-positive gastric cancer to 5-FU chemotherapy. The study identifies two subtypes of CDX2+ GC based on REG4 expression, with REG4hi subtype showing poorer survival and differentiation. The research demonstrates that CPI-637, a CBP/p300 inhibitor, effectively inhibits CDX2+ REG4hi GC cells, leading to tumor growth inhibition and increased sensitivity to 5-FU. The findings suggest that targeting CBP can overcome chemoresistance in CDX2+ REG4hi GC, providing a potential therapeutic strategy for improving 5-FU-based chemotherapy efficacy in this subtype of gastric cancer. [Extracted from the article]

Erlotinib, an EGFR tyrosine kinase inhibitor, is used for treating patients with cancer exhibiting EGFR overexpression or mutation. However, the response rate of erlotinib is low among patients with gastric cancer (GC). The findings of this study illustrated that the overexpression of bromodomain PHD finger transcription factor (BPTF) is partially responsible for erlotinib resistance in GC, and the combination of the BPTF inhibitor AU‐1 with erlotinib synergistically inhibited tumor growth both in vivo and in vitro. AU‐1 inhibited the epigenetic function of BPTF and decreased the transcriptional activity of c‐MYC on PLCG1 by attenuating chromosome accessibility of the PLCG1 promoter region, thus decreasing the expression of p‐PLCG1 and p‐Erk and eventually improving the sensitivity of GC cells to erlotinib. In patient‐derived xenograft (PDX) models, AU‐1 monotherapy exhibited remarkable tumor‐inhibiting activity and is synergistic anti‐tumor effects when combined with erlotinib. Altogether, the findings illustrate that BPTF affects the responsiveness of GC to erlotinib by epigenetically regulating the c‐MYC/PLCG1/pErk axis, and the combination of BPTF inhibitors and erlotinib is a viable therapeutic approach for GC. [ABSTRACT FROM AUTHOR]

Accumulating evidence has indicated that microRNAs (miRNAs) act as critical epigenetic regulators in tumor carcinogenesis. Here, we report that miR-199a-3p was significantly upregulated in gastric cancer (GC) cell lines and tissues. Functional studies demonstrated that miR-199a-3p dramatically increased cell proliferation and suppressed cell apoptosis both in vitro and in vivo. Furthermore, the transcriptional regulator zinc fingers and homeoboxes 1 ( ZHX1 ) was identified as one of the direct downstream targets of miR-199a-3p, miR-199a-3p bound to the ZHX1 3′ untranslated region (3′UTR) to regulate ZHX1 protein expression. In addition, the expression of miR-199a-3p was inversely associated with that of ZHX1 in GC cell lines. Overexpression of miR-199a-3p in SGC-7901 cells inhibited ZHX1 expression, while reduction in miR-199a-3p by inhibitors in NCI-N87 cells enhanced ZHX1 expression. Moreover, restoring ZHX1 expression in SGC-7901/miR-199a-3p cells inhibited the cell proliferation induced by miR-199a-3p. Taken together, these findings suggest that miR-199a-3p may function as a novel tumor promoter in GC and its oncogenic activity may involve the direct targeting and inhibition of ZHX1 . [ABSTRACT FROM AUTHOR]

Abstract: Accumulating evidence has shown that microRNAs are involved in multiple processes in cancer development and progression. Here, we report that expression of miR-625 is significantly down-regulated and negatively correlated with lymph node metastasis in gastric cancer. miR-625 significantly inhibits invasion and metastasis of gastric cancer cells both in vitro and in vivo. Moreover, we identify that ILK is a direct target gene for miR-625 and knockdown of ILK has a phenocopy of overexpression of miR-625. Taken together, our findings suggest that miR-625 plays an important role in the mechanism of tumor metastasis. [Copyright &y& Elsevier]