Dual Opposed Survival-supporting and Death-promoting Roles of Autophagy in Cancer Cells: A Concise Review

Inhibition of PI3K/AKT signaling using BKM120 reduced the proliferation and migration potentials of colorectal cancer cells and enhanced cisplatin-induced cytotoxicity

BACKGROUND

Although extensive efforts have been made to improve the treatment of colorectal cancer (CRC) patients, the prognosis for these patients remains poor. A wide range of anti-cancer agents has been applied to ameliorate the clinical management of CRC patients; however, drug resistance develops in nearly all patients. Based on the prominent role of PI3K/AKT signaling in the development of CRC and current interest in the application of PI3K inhibitors, we aimed to disclose the exact mechanism underlying the efficacy of BKM120, a well-known pan-class I PI3K inhibitor, in CRC-derived SW480 cells.

MATERIALS AND METHODS

The effects of BKM120 on SW480 cells were studied using MTT assay, cell cycle assay, Annexin V/PI apoptosis tests, and scratch assay. In the next step, qRT-PCR was used to investigate the underlying molecular mechanisms by which the PI3K inhibitor could suppress the survival of SW480 cells.

RESULT

The results of the MTT assay showed that BKM120 could decrease the metabolic activity of SW480 cells in a concentration and time-dependent manner. Investigating the exact mechanism of BKM120 showed that this PI3K inhibitor induces its anti-survival effects through a G2/M cell cycle arrest and apoptosis-mediated cell death. Moreover, the scratch assay demonstrated that PI3K inhibition led to the inhibition of cancer invasion and inhibition of PI3K/AKT signaling remarkably sensitized SW480 cells to Cisplatin.

CONCLUSION

Based on our results, inhibition of PI3K/AKT signaling can be a promising approach, either as a single modality or in combination with Cisplatin. However, further clinical studies should be performed to improve our understanding.

Improvement of Metabolic and Histological Changes of Adiposity in Rats by Synthetic Oleoyl Chalcones

We previously reported that synthetic oleoyl chalcones had a favorable effect to alleviate metabolic consequences of obesity in male SD rats. In this work, we prepared and characterized by spectroscopic tools, a set of six oleoyl chalcones (5a-c, 10 and 11a,b). The comparative effects of the previously prepared oleoyl chalcones and their new synthetic analogs on metabolic and histological changes in obese male SD rats were studied. It was found that the oleoyl chalcones III_a and IV were the best in improving many metabolic parameters, e. g., FBG, FI, ISI, TG, and total cholesterol. They cured systemic inflammation, through inhibition of the TNF-α and induction of adiponectin production. Moreover, chalcones III_a and IV alleviated the oxidative stress accompanying obesity through the induction of the antioxidant enzymes GPX, SOD and CAT besides, GSH. Interestingly, chalcones III_a and IV exerted hepatoprotective potency and ameliorated the manifestations of NAFLD via inhibition of apoptosis and induction of autophagy of hepatic cells. In conclusion, the oleoyl chalcones III_a and IV were the most effective candidates among the series of synthetic chalcones in correcting body weight and the consequent metabolic and histological changes in adiposity.

Possible Selective Cytotoxicity of Vanadium Complex on Breast Cancer Cells Involving Pathophysiological Pathways

Background:

Triple-Negative Breast Cancers (TNBC) are among the most aggressive and therapyresistant breast tumors. Development of new treatment strategies that target pathways involved in cancer cells resistance is an attractive candidate to overcome therapeutic resistance.

Objective:

To clarify the antitumor activity of [VO (bpy)2 Cl] Cl complex as a new therapeutic agent through studying the interplay between apoptosis, autophagy and notch signaling pathways.

Methods:

Proliferation of MDA-MB-231 cells and IC50 value of the vanadium complex were assessed by MTT assay. Flow cytometry was utilized to detect cell cycle distribution, apoptosis assay, LC3 levels and Acid Vascular Organelles (AVOs). Caspase 3 levels were detected by ELISA. Changes in Notch1 gene expression were assessed by real-time PCR. AVOs qualitative detection was assessed by a fluorescence microscope.

Results:

The growth of MDA-MB-231 cells was suppressed after treatment with [VO (bpy)2 Cl] Cl complex, in a dose-dependent manner. The affinity for apoptotic cell death induction was shown through the increase in the sub G0 peak, the percentage of early and late apoptotic phases, and the elevation in caspase 3 levels. The affinity for autophagic cell death induction was observed through the increase in the G0/G1 phase, G2/M arrest, the increase of AVOs red fluorescence and elevated LC3 levels. The affinity for notch pathway inhibition was shown through the suppression of Notch 1 gene expression.

Conclusion:

[VO (bpy)2 Cl] Cl complex could be a promising candidate as therapeutic agent targeting different therapeutic targets including apoptosis, autophagy and notch signaling pathways.