Efficacy of HMJ-38, a new quinazolinone analogue, against the gemcitabine-resistant MIA-PaCa-2 pancreatic cancer cells.

Gemcitabine is frequently utilized to treat pancreatic cancer. The purpose of our study was to create a gemcitabine-resistant MIA-PaCa-2 pancreatic cancer cell line (MIA-GR100) and to evaluate the anti-pancreatic cancer efficacy of HMJ-38, a new quinazolinone analogue. Compared to their parental counterparts, MIA-PaCa-2, established MIA-GR100 cells were less sensitive to gemcitabine. MIA-GR100 cell viability was not affected by 10, 50 and 100 nM gemcitabine concentrations. HMJ-38 reduced MIA-GR100 cell growth and induced autophagy and apoptosis. When stained with monodansylcadaverine (MDC), acridine orange (AO), and terminal deoxynucleotide transferase dUTP nick end labeling (TUNEL), MIA-GR100 cells shrunk, punctured their membranes, and produced autophagy vacuoles and apoptotic bodies. Combining chloroquine (CQ) and 3-methyladenine (3-MA) with HMJ-38 dramatically reduced cell viability, indicating that autophagy function as a cytoprotective mechanism. MIA-GR100 cells treated with both z-VAD-FMK and HMJ-38 were much more viable than those treated with HMJ-38 alone. HMJ-38 promotes apoptosis in MIA-GR100 cells by activating caspases. Epidermal growth factor receptor (EGFR) is one of HMJ-38's principal targets, as determined via in silico target screening with network prediction. HMJ-38 also inhibited EGFR kinase activity and EGFR-associated signaling in MIA-GR100 cells. HMJ-38 may be an effective chemotherapeutic adjuvant for gemcitabine-resistant pancreatic cancer cells, in which it induces an antitumor response.

Hematopoietically expressed homeobox gene is associated with type 2 diabetes in KK Cg-Ay/J mice and a Taiwanese Han Chinese population.

Diabetes mellitus (DM) is a chronic disease. The KK Cg-Ay/J (KK-Ay) mouse is an animal model to study type 2 diabetes mellitus (T2D) disease. The present study assessed the expression of hematopoietically expressed homeobox (HHEX) protein in liver tissues of different age groups of mice (6, 16 and 42 weeks) by immunohistochemistry (IHC). The results demonstrated a significant decrease in the percentage of HHEX-positive cells in KK-Ay mice as compared with that in KK-α/α control mice. Furthermore, in Taiwan's Han Chinese population, genotypic and allelic frequency distributions of the rs61862780 single-nucleotide polymorphism (SNP) in the HHEX gene were investigated. The results demonstrated that in the rs61862780 SNP of the 3'-untranslated region (UTR) of HHEX, the frequency of the CC genotype was higher in patients (6.0%) than in controls (2.7%), while the TT genotype frequency was about equal. In the same SNP, the frequency of the C allele was higher in patients (21.0%) than in controls (17.3%), while the T allele frequency was about equal. These results may pave the road for exploring the KK-Ay mouse model and the HHEX SNP rs61862780, which was correlated with the susceptibility to T2D in a Chinese population. Based on these findings, an association of HHEX gene expression with pathological features of T2D was indicated.

Pterostilbene modulates the suppression of multidrug resistance protein 1 and triggers autophagic and apoptotic mechanisms in cisplatin-resistant human oral cancer CAR cells via AKT signaling.

Pterostilbene is a natural polyphenolic compound that is primarily found in fruits, such as blueberries and has a similar structure to resveratrol. Pterostilbene exhibits antioxidant, anti-inflammatory and antitumor activity but the effects of pterostilbene on drug-resistant oral cancer cells and its underlying mechanisms of action have not yet been explored. Therefore, the present study was performed to clarify the anticancer effects of pterostilbene on cisplatin-resistant human oral cancer CAR cells. The results demonstrated that CAR cells exhibited marked shrinkage, cell membrane breakage and autophagic vacuole formation following treatment with pterostilbene. Pterostilbene also effectively inhibited cell viability and suppressed cell confluence in a time- and concentration-dependent manner. Probing with acridine orange, monodansylcadaverine and LysoTracker Red demonstrated that the number of acidic vesicular organelles was increased, indicating increased autophagy. Furthermore, Heochst 33342 staining determined that DNA condensation, a characteristic of apoptosis, was enhanced following treatment with pterostilbene. Furthermore, pterostilbene upregulated mRNA levels of LC3-II and Atg12, as well as the expression of Atgs/Beclin-1/LC3-associated signaling, suggesting that it enhances autophagy. The autophagy inhibitors 3-methyladenine and chloroquine were used to confirm that pterostilbene induces autophagy. It was also determined that pterostilbene triggered caspase-dependent apoptosis by directly testing DNA breakage and using the pan-caspase inhibitor carbobenzoxyvalyl-alanyl-aspartyl fluoromethyl ketone. The results demonstrated that pterostilbene mediates the apoptosis of CAR cells via the intrinsic apoptotic cascade. In addition, pterostilbene inhibited MDR1 expression and the phosphorylation of AKT on the Ser473 site in CAR cells. Therefore, pterostilbene may elicit an oral anticancer response in drug-resistant cells and may be used as a chemotherapeutic adjuvant to treat patients with oral cancer.

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study.

Curcumin has been shown to exert potential antitumor activity in vitro and in vivo involved in multiple signaling pathways. However, the application of curcumin is still limited because of its poor hydrophilicity and low bio-availability. In the present study, we investigated the therapeutic effects of a novel and water soluble bis(hydroxymethyl) alkanoate curcuminoid derivative, MTH-3, on human breast adenocarcinoma MDA-MB-231 cells. This study investigated the effect of MTH-3 on cell viability, cell cycle and induction of autophagy and apoptosis in MDA-MB-231 cells. After 24-h treatment with MTH-3, a concentration-dependent decrease in MDA-MB-231 cell viability was observed, and the IC50 value was 5.37±1.22 µM. MTH-3 significantly triggered G2/M phase arrest and apoptosis in MDA-MB-231 cells. Within a 24-h treatment, MTH-3 decreased the CDK1 activity by decreasing CDK1 and cyclin B1 protein levels. MTH-3-induced apoptosis was further confirmed by morphological assessment and annexin V/PI staining assay. Induction of apoptosis caused by MTH-3 was accompanied by an apparent increase of DR3, DR5 and FADD and, as well as a marked decrease of Bcl-2 and Bcl-xL protein expression. MTH-3 also decreased the protein levels of Ero1, PDI, PERK and calnexin, as well as increased the expression of IRE1α, CHOP and Bip that consequently led to ER stress and MDA-MB-231 cell apoptosis. In addition, MTH-3-treated cells were involved in the autophagic process and cleavage of LC3B was observed. MTH-3 enhanced the protein levels of LC3B, Atg5, Atg7, Atg12, p62 and Beclin-1 in MDA-MB-231 cells. Finally, DNA microarray was carried out to investigate the level changes of gene expression modulated by MTH-3 in MDA-MB-231 cells. Taken together, our results suggest that MTH-3 might be a novel therapeutic agent for the treatment of triple-negative breast cancer in the near future.

YC-1 induces G0/G1 phase arrest and mitochondria-dependent apoptosis in cisplatin-resistant human oral cancer CAR cells.

Oral cancer is a serious and fatal disease. Cisplatin is the first line of chemotherapeutic agent for oral cancer therapy. However, the development of drug resistance and severe side effects cause tremendous problems clinically. In this study, we investigated the pharmacologic mechanisms of YC-1 on cisplatin-resistant human oral cancer cell line, CAR. Our results indicated that YC-1 induced a concentration-dependent and time-dependent decrease in viability of CAR cells analyzed by MTT assay. Real-time image analysis of CAR cells by IncuCyte™ Kinetic Live Cell Imaging System demonstrated that YC-1 inhibited cell proliferation and reduced cell confluence in a time-dependent manner. Results from flow cytometric analysis revealed that YC-1 promoted G0/G1 phase arrest and provoked apoptosis in CAR cells. The effects of cell cycle arrest by YC-1 were further supported by up-regulation of p21 and down-regulation of cyclin A, D, E and CDK2 protein levels. TUNEL staining showed that YC-1 caused DNA fragmentation, a late stage feature of apoptosis. In addition, YC-1 increased the activities of caspase-9 and caspase-3, disrupted the mitochondrial membrane potential (AYm) and stimulated ROS production in CAR cells. The protein levels of cytochrome c, Bax and Bak were elevated while Bcl-2 protein expression was attenuated in YC-1-treated CAR cells. In summary, YC-1 suppressed the viability of cisplatin-resistant CAR cells through inhibiting cell proliferation, arresting cell cycle at G0/G1 phase and triggering mitochondria-mediated apoptosis. Our results provide evidences to support the potentially therapeutic application of YC-1 on fighting against drug resistant oral cancer in the future.

Resveratrol-induced autophagy and apoptosis in cisplatin-resistant human oral cancer CAR cells: A key role of AMPK and Akt/mTOR signaling.

Resveratrol is known to be an effective chemo-preventive phytochemical against multiple tumor cells. However, the increasing drug resistance avoids the cancer treatment in oral cavity cancer. In this study, we investigated the oral antitumor activity of resveratrol and its mechanism in cisplatin-resistant human oral cancer CAR cells. Our results demonstrated that resveratrol had an extremely low toxicity in normal oral cells and provoked autophagic cell death to form acidic vesicular organelles (AVOs) and autophagic vacuoles in CAR cells by acridine orange (AO) and monodansylcadaverine (MDC) staining. Either DNA fragmentation or DNA condensation occurred in resveratrol-triggered CAR cell apoptosis. These inhibitors of PI3K class III (3-MA) and AMP-activated protein kinase (AMPK) (compound c) suppressed the autophagic vesicle formation, LC3-II protein levels and autophagy induced by resveratrol. The pan-caspase inhibitor Z-VAD-FMK attenuated resveratrol-triggered cleaved caspase-9, cleaved caspase-3 and cell apoptosis. Resveratrol also enhanced phosphorylation of AMPK and regulated autophagy- and pro-apoptosis-related signals in resveratrol-treated CAR cells. Importantly, resveratrol also stimulated the autophagic mRNA gene expression, including Atg5, Atg12, Beclin-1 and LC3-II in CAR cells. Overall, our findings indicate that resveratrol is likely to induce autophagic and apoptotic death in drug-resistant oral cancer cells and might become a new approach for oral cancer treatment in the near future.