PVT1 has been identified as an enhancer of and also functions as a stabilizer of c-Myc protein (39)
PVT1 has been identified as an enhancer of and also functions as a stabilizer of c-Myc protein (39). chemoresistant malignancy cells by inhibiting the manifestation of the PRC2 subunit EZH2 and its related lncRNA PVT1. Curcumin was also found to prevent the formation of spheroids, a hallmark of CSCs, and to down-regulate several self-renewal traveling genes. In addition, we confirmed our findings inside a xenograft mouse model where curcumin inhibited gemcitabine-resistant tumor growth. Overall, this study shows medical relevance for combining curcumin with chemotherapy to conquer chemoresistance Alpelisib hydrochloride in PDAC. Intro Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive malignancies and the fourth leading cause of cancer-related deaths in the United States (1). While curative resection and chemotherapy is the standard of care for PDAC individuals, in most cases it only provides a short-term survival Alpelisib hydrochloride benefit. Furthermore, the majority of these individuals will eventually develop resistance to therapeutic medicines through several mechanisms including the activation of multidrug resistance and pro-survival pathways (2C4). There is accumulating evidence that malignancy stem cells (CSCs) present in PDAC tumors, which have high Alpelisib hydrochloride tumorigenic capabilities to self-renew and produce differentiated progeny, contribute to chemoresistance (5C10). It is speculated that standard chemotherapy reduces the tumor mass by influencing rapidly dividing PDAC cells that constitute the bulk of the tumor, but fails to target CSCs. This results in treatment failure and tumor recurrence (11). Consequently, a better understanding of the molecular events characterizing pancreatic CSCs is necessary to identify improved therapeutic targets to overcome chemoresistance. Enhancer of Zeste Homolog-2 (EZH2), a catalytic subunit of polycomb repressive complex 2 (PRC2), is usually a histone methyltransferase that epigenetically maintains CSCs by regulating gene expression (12,13). A recent study found that EZH2 Rabbit polyclonal to KCNC3 was overexpressed in the nucleus of ~70% of PDACs, highlighting its key oncogenic role in PDACs (14). Furthermore, Alpelisib hydrochloride overexpression of EZH2 in a PDAC cell line resulted in enhanced resistance to gemcitabine, a first-line drug for treatment of PDACs (14). One of the mechanisms by which EZH2 acts as an oncogene in PDAC is usually by modulating long non-coding RNA (lncRNA) PVT1 (15C17), a known inducer of drug resistance in PDAC (18). While the roles of other non-coding RNAs such as microRNAs have been well established in cancers over the last decade, the functional roles of lncRNAs in cancers have only recently started to come to light. Several studies have therapeutically targeted EZH2 and PVT1 individually (13,18C21); however, whether co-targeting these two genes could further attenuate chemoresistance in pancreatic cancer remains to be decided. Molecular inhibitors that specifically target certain genes or cellular pathways can only provide a short delay to almost inevitable cancer progression; cancer cells will eventually acquire resistance to these inhibitors by activating alternative cellular pathways. Multi-gene inhibitors can significantly prolong chemosensitivity over conventional therapeutic brokers by simultaneously suppressing several oncogenic pathways. However, the likelihood of off-target effects as well as the complexities involved in the assessment of drug efficacy have hindered the development of such drugs. Over the past decades, numerous studies have shown that curcumin, a phenolic compound extracted from Online. For all those experiments, each sample was run in duplicate. Western blotting Following 48-h treatment with curcumin and/or gemcitabine, total cellular protein was extracted and western immunoblotting was performed as described previously (32). Supplementary Table 2, available at Online, lists the primary antibodies that were used. Secondary anti-mouse or Alpelisib hydrochloride anti-rabbit antibodies were purchased from Santa Cruz Biotechnology (Dallas, TX). -actin (Sigma-Aldrich) was used as a reference.