scholarly journals Alternative Pathways of Cancer Cell Death by Rottlerin: Apoptosis versus Autophagy

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Claudia Torricelli ◽  
Sara Salvadori ◽  
Giuseppe Valacchi ◽  
Karel Souček ◽  
Eva Slabáková ◽  
...  

Since the ability of cancer cells to evade apoptosis often limits the efficacy of radiotherapy and chemotherapy, autophagy is emerging as an alternative target to promote cell death. Therefore, we wondered whether Rottlerin, a natural polyphenolic compound with antiproliferative effects in several cell types, can induce cell death in MCF-7 breast cancer cells. The MCF-7 cell line is a good model of chemo/radio resistance, being both apoptosis and autophagy resistant, due to deletion of caspase 3 gene, high expression of the antiapoptotic protein Bcl-2, and low expression of the autophagic Beclin-1 protein. The contribution of autophagy and apoptosis to the cytotoxic effects of Rottlerin was examined by light, fluorescence, and electron microscopic examination and by western blotting analysis of apoptotic and autophagic markers. By comparing caspases-3-deficient (MCF-73def) and caspases-3-transfected MCF-7 cells (MCF-73trans), we found that Rottlerin induced a noncanonical, Bcl-2-, Beclin 1-, Akt-, and ERK-independent autophagic death in the former- and the caspases-mediated apoptosis in the latter, in not starved conditions and in the absence of any other treatment. These findings suggest that Rottlerin could be cytotoxic for different cancer cell types, both apoptosis competent and apoptosis resistant.

2020 ◽  
Vol 10 ◽  
Author(s):  
Nurul Atiqah Sulaiman ◽  
Rajan Rajabalaya ◽  
Shirley Huan Fang Lee ◽  
Ya Chee Lim ◽  
Wei Hon Lim ◽  
...  

Background: Commercially available Clinacanthus nutans (Burm.F) Lindau (Acanthaceae) (CN) leaf preparations are gaining attention as an alternative cancer treatment, particularly in South East Asia. Multiple studies have suggested that CN has potential anticancer activities; however, the mechanism of these activities has remained elusive. Objective: This study evaluated the cytotoxic mechanisms of CN extracts in cancer cells. Methods: CN extracts were prepared from either fresh or dried leaves, using different solvents. Cytotoxicity of CN extracts were tested on the A549 (lung cancer), HeLa (cervical cancer), MCF-7 (breast cancer) and MDA-MB-231 (breast cancer) cell lines using the MTT assay. Flow cytometry was used to assess changes in the cell cycle profile, while Western blotting was used to examine microtubule stability. Finally, the mode of cell death was investigated using the Annexin V-FITC Apoptosis Detection Kit. Results: Aqueous Fresh (AQF) extract was prepared to simulate the ethno-medicinal use of CN, and reduced cell viability of MCF-7 cells with IC50 = 1.71 mg/mL. Some CN extracts have the ability to inhibit the proliferation of four different cancer cell lines after a 24 hour treatment. Annexin V assay results shows that acetone extracts of CN induced increments in percentage of apoptotic cell death. However, flow cytometry results show that cancer cell cycle profile were not affected. Similarly, immunoblotting results also indicate that microtubule dynamics in MCF-7 cells were not altered. However, the aqueous extract, prepared to simulate the current ethnomedicinal use of CN leaves in cancer treatment, did not significantly inhibit cancer cell proliferation with IC50 = 1.71 mg/mL. Conclusions: This study was the first to show that microtubules in cancer cells remain dynamic after treatment with CN extracts, effectively ruling interference of microtubule dynamics as the mode of cell death. AMD extract showed the highest effects MCF-7 cell proliferation.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Firdos Alam Khan ◽  
Sultan Akhtar ◽  
Dana Almohazey ◽  
Munthar Alomari ◽  
Sarah Ameen Almofty

Both nanoparticles and cloves (Syzygium aromaticum) possess anticancer properties, but they do not elicit a significant response on cancer cells when treated alone. In the present study, we have tested fluorescent magnetic submicronic polymer nanoparticles (FMSP-nanoparticles) in combination with crude clove extracts on human breast cancer cells (MCF-7) to examine whether the combination approach enhance the cancer cell death. The MCF-7 cells were treated with different concentrations (1.25 μg/mL, 12.5 μg/mL, 50 μg/mL, 75 μg/mL, and 100 μg/mL) of FMSP-nanoparticles alone and in combination with 50 μg/mL crude clove extracts. The effects of FMSP-nanoparticles alone and combined with clove extracts were observed after 24 hrs and 48 hrs intervals. The response of FMSP-nanoparticles-treated cells was evaluated by Trypan Blue, 4′,6-diamidino-2-phenylindole (DAPI), and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively. We have demonstrated that cancer cell viability was decreased to 55.40% when treated with FMSP-nanoparticles alone, whereas when cancer cells were treated with FMSP-nanoparticles along with crude clove extracts, the cell viability was drastically decreased to 8.50%. Both morphological and quantitative data suggest that the combination of FMSP-nanoparticles plus crude clove extracts are more effective in treating cancer cells and we suggest that the combination treatment of nanoparticles along with clove extracts hold a great promise for the cancer treatments.


2012 ◽  
Vol 109 (38) ◽  
pp. 15115-15120 ◽  
Author(s):  
Drew J. Adams ◽  
Mingji Dai ◽  
Giovanni Pellegrino ◽  
Bridget K. Wagner ◽  
Andrew M. Stern ◽  
...  

Piperlongumine is a naturally occurring small molecule recently identified to be toxic selectively to cancer cells in vitro and in vivo. This compound was found to elevate cellular levels of reactive oxygen species (ROS) selectively in cancer cell lines. The synthesis of 80 piperlongumine analogs has revealed structural modifications that retain, enhance, and ablate key piperlongumine-associated effects on cells, including elevation of ROS, cancer cell death, and selectivity for cancer cells over nontransformed cell types. Structure/activity relationships suggest that the electrophilicity of the C2-C3 olefin is critical for the observed effects on cells. Furthermore, we show that analogs lacking a reactive C7-C8 olefin can elevate ROS to levels observed with piperlongumine but show markedly reduced cell death, suggesting that ROS-independent mechanisms, including cellular cross-linking events, may also contribute to piperlongumine’s induction of apoptosis. In particular, we have identified irreversible protein glutathionylation as a process associated with cellular toxicity. We propose a mechanism of action for piperlongumine that may be relevant to other small molecules having two sites of reactivity, one with greater and the other with lesser electrophilicity.


Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1194
Author(s):  
Ana Rita Garizo ◽  
Lígia F. Coelho ◽  
Sandra Pinto ◽  
Tiago P. Dias ◽  
Fábio Fernandes ◽  
...  

Peptides have been thoroughly studied as new therapeutic strategies for cancer treatment. In this work, we explored in vitro the anticancer potential of three novel peptides derived from the C-terminal of azurin, an anticancer bacterial protein produced by Pseudomonas aeruginosa. CT-p26, CT-p19 and CT-p19LC peptides were previously obtained through an in silico peptide design optimization process, CT-p19LC being the most promising as it presented higher hydrophobicity and solubility, positive total charge and, most importantly, greater propensity for anticancer activity. Therefore, in this study, through proliferation and apoptosis assays, CT-p19LC was tested in four cancer cell lines—A549, MCF-7, HeLa and HT-29—and in two non-cancer cell lines—16HBE14o- and MCF10A. Its membrane-targeting activity was further evaluated with zeta potential measurements and membrane order was assessed with the Laurdan probe. The results obtained demonstrated that CT-p19LC decreases cell viability through induction of cell death and binds to the plasma membrane of cancer cells, but not to non-cancer cells, making them less rigid. Overall, this study reveals that CT-p19LC is an auspicious selective anticancer peptide able to react with cancer cell membranes and cause effective action.


2018 ◽  
Vol 18 (17) ◽  
pp. 1483-1493
Author(s):  
Ricardo Imbroisi Filho ◽  
Daniel T.G. Gonzaga ◽  
Thainá M. Demaria ◽  
João G.B. Leandro ◽  
Dora C.S. Costa ◽  
...  

Background: Cancer is a major cause of death worldwide, despite many different drugs available to treat the disease. This high mortality rate is largely due to the complexity of the disease, which results from several genetic and epigenetic changes. Therefore, researchers are constantly searching for novel drugs that can target different and multiple aspects of cancer. Experimental: After a screening, we selected one novel molecule, out of ninety-four triazole derivatives, that strongly affects the viability and proliferation of the human breast cancer cell line MCF-7, with minimal effects on non-cancer cells. The drug, named DAN94, induced a dose-dependent decrease in MCF-7 cells viability, with an IC50 of 3.2 ± 0.2 µM. Additionally, DAN94 interfered with mitochondria metabolism promoting reactive oxygen species production, triggering apoptosis and arresting the cancer cells on G1/G0 phase of cell cycle, inhibiting cell proliferation. These effects are not observed when the drug was tested in the non-cancer cell line MCF10A. Using a mouse model with xenograft tumor implants, the drug preventing tumor growth presented no toxicity for the animal and without altering biochemical markers of hepatic function. Results and Conclusion: The novel drug DAN94 is selective for cancer cells, targeting the mitochondrial metabolism, which culminates in the cancer cell death. In the end, DAN94 has been shown to be a promising drug for controlling breast cancer with minimal undesirable effects.


2021 ◽  
Author(s):  
Wooram Park ◽  
Seok-Jo Kim ◽  
Paul Cheresh ◽  
Jeanho Yun ◽  
Byeongdu Lee ◽  
...  

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein,...


Cells ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Umamaheswari Natarajan ◽  
Thiagarajan Venkatesan ◽  
Vijayaraghavan Radhakrishnan ◽  
Shila Samuel ◽  
Appu Rathinavelu

Gene expression is often altered by epigenetic modifications that can significantly influence the growth ability and progression of cancers. SAHA (Suberoylanilide hydroxamic acid, also known as Vorinostat), a well-known Histone deacetylase (HDAC) inhibitor, can stop cancer growth and metastatic processes through epigenetic alterations. On the other hand, Letrozole is an aromatase inhibitor that can elicit strong anti-cancer effects on breast cancer through direct and indirect mechanisms. A newly developed inhibitor, RG7388 specific for an oncogene-derived protein called MDM2, is in clinical trials for the treatment of various cancers. In this paper, we performed assays to measure the effects of cell cycle arrest resulting from individual drug treatments or combination treatments with SAHA + letrozole and SAHA + RG7388, using the MCF-7 breast cancer cells. When SAHA was used individually, or in combination treatments with RG7388, a significant increase in the cytotoxic effect was obtained. Induction of cell cycle arrest by SAHA in cancer cells was evidenced by elevated p21 protein levels. In addition, SAHA treatment in MCF-7 cells showed significant up-regulation in phospho-RIP3 and MLKL levels. Our results confirmed that cell death caused by SAHA treatment was primarily through the induction of necroptosis. On the other hand, the RG7388 treatment was able to induce apoptosis by elevating BAX levels. It appears that, during combination treatments, with SAHA and RG7388, two parallel pathways might be induced simultaneously, that could lead to increased cancer cell death. SAHA appears to induce cell necroptosis in a p21-dependent manner, and RG7388 seems to induce apoptosis in a p21-independent manner, outlining differential mechanisms of cell death induction. However, further studies are needed to fully understand the intracellular mechanisms that are triggered by these two anti-cancer agents.


Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 743
Author(s):  
Oluwaseun Akinyele ◽  
Heather M. Wallace

Breast cancer is a complex heterogeneous disease with multiple underlying causes. The polyamines putrescine, spermidine, and spermine are polycationic molecules essential for cell proliferation. Their biosynthesis is upregulated in breast cancer and they contribute to disease progression. While elevated polyamines are linked to breast cancer cell proliferation, there is little evidence to suggest breast cancer cells of different hormone receptor status are equally dependent on polyamines. In this study, we characterized the responses of two breast cancer cells, ER+ (oestrogen receptor positive) MCF-7 and ER- MDA-MB-231 cell lines, to polyamine modulation and determined the requirement of each polyamine for cancer cell growth. The cells were exposed to DFMO (a polyamine pathway inhibitor) at various concentrations under different conditions, after which several growth parameters were determined. Exposure of both cell lines to DFMO induced differential growth responses, MCF-7 cells showed greater sensitivity to polyamine pathway inhibition at various DFMO concentrations than the MDA-MB-231 cells. Analysis of intracellular DFMO after withdrawal from growth medium showed residual DFMO in the cells with concomitant decreases in polyamine content, ODC protein level, and cell growth. Addition of exogenous polyamines reversed the cell growth inhibition, and this growth recovery appears to be partly dependent on the spermidine content of the cell. Similarly, DFMO exposure inhibits the global translation state of the cells, with spermidine addition reversing the inhibition of translation in the breast cancer cells. Taken together, these data suggest that breast cancer cells are differentially sensitive to the antitumour effects of polyamine depletion, thus, targeting polyamine metabolism might be therapeutically beneficial in breast cancer management based on their subtype.


2021 ◽  
Vol 11 (2) ◽  
pp. 326-332
Author(s):  
Le Ma ◽  
Zhenyu Liu ◽  
Zhimin Fan

Breast cancer is one of the most prevailing cancers in females, while the cancerous heterogeneity hinders its early diagnosis and subsequent therapy. miR-143-3p is a critical mediator in malignancy development and tumorigenesis as a tumor suppressor. Its role in various tumor entities has been investigated, such as colon cancer and breast cancer. Using MCF-7 breast cancer cell model, we planned to explore the underlying mechanisms of miR-143/KLF-5 axis in retarding breast cancer cells growth. Bioinformatics analysis searched the target KLF5 of miR-143, and the miR-143-targeted mimic and inhibitor were employed to detect the changes of KLF5. After transfection of mimic miR-143, the CCK-8 reagent assessed cell proliferation. Based on optimal stimulation time, miR-143 stimulation model was established, followed by determining expression of KLF5, EGFR and PCNA via western blot and qPCR. Eventually, siRNA-KLF5 was applied to silencing KLF5 level to evaluate its role in MCF-7 cells. The transcription and translation levels of KLF5 were diminished in miR-143-mimic transfected MCF-7 cells, while enhanced in miR-143-inhibitor transfected MCF-7 cells. When MCF-7 cells were transfected with miR-143-mimic at different time points, 48 hours was found to be the optimal transfection time, with reduced transcription and translation levels of KLF5, EGFR and PCNA. The transcription and translation levels of PNCA and EGFR were declined after silencing KLF5 by siRNA. miR-143/KLF5 axis could retard the proliferation of MCF-7 breast cancer cells.


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