The effects of STA-9090 (Ganetespib) and venetoclax (ABT-199) combination on apoptotic pathways in human cervical cancer cells

Dual targeting of HSP90 and BCL-2 in breast cancer cells using inhibitors BIIB021 and ABT-263

PURPOSE

The incidence of breast cancer has been increasing in recent years, and monotherapy approaches are not sufficient alone in the treatment of breast cancer. In the combined therapy approach, combining two or three different agents in lower doses can mitigate the side effects on living cells and tissues caused by high doses of chemical agents used alone. ABT-263 (navitoclax), a clinically tested Bcl-2 family protein inhibitor, has shown limited success in clinical trials due to the development of resistance to monotherapy in breast cancer cells. This resistance shows that monotherapy approaches are inadequate and more effective treatment strategies are needed. It is the ability of HSP90 inhibitors to destabilize many oncoproteins that are critical for the survival of cancer cells. This study aimed to examine the anticancer activity of the combination of ABT-263 with BIIB021, a new generation HSP90 inhibitor, on two widely used breast cancer cell lines: MCF-7 (ER-positive) and MDA-MB-231 (triple-negative breast cancer, TNBC). These cell lines were selected to represent distinct breast cancer subtypes with different molecular characteristics and clinical behaviors.

METHODS

Single and combined cytotoxic effects of this agents on MCF-7 and MDA-MB-231 breast cancer cell lines were determined using the MTT cell viability test. The combined use of these two agents showed a synergistic effect, and this effect was assigned using the Chou and Talalay method. mRNA and protein levels of apoptosis-related genes Bax, Bcl-2, Casp9, and Heat Shock Proteins HSP27, HSP70, and HSP90 were analyzed using Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Western Blotting, respectively.

RESULTS

The cytotoxicity analysis, combined with the application of the Chou-Talalay method, demonstrated that the BIIB021 and ABT-263 combination exhibited significantly greater anticancer activity compared to the individual effects of either BIIB021 or ABT-263 in breast cancer cell lines. The analysis of mRNA and protein levels indicated that the BIIB021+ABT-263 combination may have triggered the intrinsic apoptotic pathway in breast cancer cells.

CONCLUSION

This study showed that co-administration of ABT-263 and BIIB021 agents exhibited synergistic cytotoxic effects and increased the expression of apoptosis-related genes in breast cancer cell lines.

Molecular mechanism of anticancer effect of heat shock protein 90 inhibitor BIIB021 in human bladder cancer cell line

Bladder cancer is a type of urologic malignancy that exhibits significant morbidity, mortality, and treatment costs. Inhibition of heat shock protein 90 (HSP90) activity has been a promising pharmacological strategy for blocking of bladder cancer pathogenesis. BIIB021 is a next-generation HSP90 inhibitor which interrupts ATP hydrolysis process of HSP90 and inhibits the stabilization and correct folding of client proteins. In current study, we aimed to investigate the molecular mechanism of the anticancer activity of BIIB021 in human bladder cancer T24 cells. Our results revealed that nanomolar concentration of BIIB021 decreased viability of T24 cell. BIIB021 downregulated HSP90 expression in T24 cells and inhibited the refolding activity of luciferase in the presence of T24 cell lysate. PCR array data indicated a significant alteration in transcript levels of cancer-related genes involved in metastases, apoptotic cell death, cell cycle, cellular senescence, DNA damage and repair mechanisms, epithelial-to-mesenchymal transition, hypoxia, telomeres and telomerase, and cancer metabolism pathways in T24 cells. All findings hypothesize that BIIB021 could exhibit as effective HSP90 inhibitor in the future for treatment of bladder cancer patients.

Effect of dexpanthenol on cyclophosphamide-induced ovarian toxicity: a histological and molecular study in rats

RESEARCH QUESTION

Does dexpanthenol work as an effective therapeutic agent against cyclophosphamide (CYC)-induced premature ovarian failure (POF) in rats?

DESIGN

A total of 28 female Wistar Albino rats were randomly divided into four groups (n = 7 per group). The POF and POF plus dexpanthenol groups were intraperitoneally administered CYC at an initial dose of 50 mg/kg, followed by 8 mg/kg for 14 days. The dexpanthenol and POF plus dexpanthenol groups were both intraperitoneally administered dexpanthenol at a dose of 500 mg/kg/day for 15 days.

RESULTS

In the group administered CYC, the following was observed: a decrease in the ovarian index; a decrease in the numbers of primordial, primary, secondary and antral follicles; an increase in the number of corpus luteum and atretic follicles; a decrease in proliferation cell nuclear antigen immunoreactivity; a significant reduction in anti-Müllerian hormone and oestradiol levels; and an increase in serum FSH levels compared with controls. Dexpanthenol, on the other hand, reversed these effects. Quantitative reverse transcription polymerase chain reaction analyses showed that dexpanthenol increased Bcl-2, Akt1, mTOR, Nrf2 and HO-1 in CYC-induced ovarian tissues, but decreased Bax, Cas3, Hsp27, Hsp70, and Hsp90. Dexpanthenol treatment has a potential for inhibiting the intrinsic apoptotic pathway and oxidative stress levels in ovarian tissues via the downregulation of the mRNA expression of heat shock proteins and the activation of Nrf2/HO-1 pathways.

CONCLUSIONS

Our findings demonstrated that dexpanthenol is an effective agent against POF caused by CYC; however, further experimental and clinical data are needed to use it effectively.

Combination of navitoclax (Bcl-2 and Bcl-xL inhibitor) and Debio-0932 (Hsp90 inhibitor) suppresses the viability of prostate cancer cells via induction of apoptotic signaling pathway

Prostate cancer is one of the most common cancers in men. Given the diverse nature of prostate cancer and its tendency to respond differently to various treatments, combination therapies are often employed to enhance outcomes. In this study, the synergetic efficiency of chemotherapeutic drug Navitoclax and heat shock protein 90 (Hsp90) inhibitor Debio-0932 was evaluated in human prostate cancer cell line (PC3). Our results indicated that Navitoclax-Debio-0932 combination exhibited synergistic activity in PC3 cells at concentrations lower than IC50 values. The combination of Navitoclax and Debio-0932 decreased PC3 cell viability in a dose dependent manner at 48 h. To investigate the apoptotic potential of the Navitoclax-Debio-0932 combination against prostate cancer cells, the mRNA and protein expression levels of apoptotic and antiapoptotic markers (Bax, Bcl-2, Bcl-xL, Cyt-c, Apaf-1, Casp-3, Casp-7, and Casp-9) were measured using RT-PCR and ELISA assay. Furthermore, the cleavage activity of Casp-3 was determined by colorimetric assay. The results revealed that Navitoclax-Debio-0932 combination potently induced intrinsic apoptotic pathway in PC3 cells rather than using drugs alone. The combined treatment of Navitoclax and Debio-0932 displayed synergistic cytotoxic and apoptotic effects on prostate cancer cells, presenting a promising approach for combination therapy in prostate cancer.