scholarly journals Role of DNA Damage and MMP Loss in Radiosensitization-Induced Apoptosis by Ellagic Acid in HeLa Cells

2020 ◽  
Vol 25775790 ◽  
pp. 1-1
Author(s):  
Vidhula R Ahire ◽  
◽  
Amit Kumar ◽  
Sushma Bhosle ◽  
Kaushala Prasad Mishra ◽  
...  

Ellagic acid (EA) is a polyphenol found in grapes, pomegranates, walnuts, etc. exhibits anti-cancer properties. The current study was conducted to understand the radiosensitizing role of EA on HeLa cells. Monotherapy of EA and radiation was initially studied on HeLa cells. The addition of EA before the radiation treatment subsequently made DNA more susceptible to damage thereby developing DNA beaks, which are known to be lethal for cell survival. This was evaluated by performing comet and γ-foci formation assay. Other assays which included cell-cycle distribution, clonogenic cell survival assay, mitochondrial membrane drop, and apoptosis were performed to evaluate the effect of EA with radiation. Our results demonstrate that, when cells were exposed to the combinatorial treatment of EA (10µM) and 2Gy of γ-radiation there was augmented cell death, lesser cell-proliferation, reduction in the colony-forming ability, increased DNA tail length, more number of γ-foci persisting even after 24h, enhanced apoptosis, augmented drop in the mitochondrial membrane potential and a G1 cell-cycle arrest. These results suggest that EA exhibits not only anti-cancer properties in terms of cell-death but also exhibits a radiosensitizing effect when given in combination with γ-radiation. Thus, it can be concluded that EA not only exhibits anticancer effects but also has potential in radiosensitizing HeLa cells.

2019 ◽  
Vol 105 (3) ◽  
pp. 839-853
Author(s):  
Aglaia Kyrilli ◽  
David Gacquer ◽  
Vincent Detours ◽  
Anne Lefort ◽  
Frédéric Libert ◽  
...  

Abstract Background The early molecular events in human thyrocytes after 131I exposure have not yet been unravelled. Therefore, we investigated the role of TSH in the 131I-induced DNA damage response and gene expression in primary cultured human thyrocytes. Methods Following exposure of thyrocytes, in the presence or absence of TSH, to 131I (β radiation), γ radiation (3 Gy), and hydrogen peroxide (H2O2), we assessed DNA damage, proliferation, and cell-cycle status. We conducted RNA sequencing to profile gene expression after each type of exposure and evaluated the influence of TSH on each transcriptomic response. Results Overall, the thyrocyte responses following exposure to β or γ radiation and to H2O2 were similar. However, TSH increased 131I-induced DNA damage, an effect partially diminished after iodide uptake inhibition. Specifically, TSH increased the number of DNA double-strand breaks in nonexposed thyrocytes and thus predisposed them to greater damage following 131I exposure. This effect most likely occurred via Gα q cascade and a rise in intracellular reactive oxygen species (ROS) levels. β and γ radiation prolonged thyroid cell-cycle arrest to a similar extent without sign of apoptosis. The gene expression profiles of thyrocytes exposed to β/γ radiation or H2O2 were overlapping. Modulations in genes involved in inflammatory response, apoptosis, and proliferation were observed. TSH increased the number and intensity of modulation of differentially expressed genes after 131I exposure. Conclusions TSH specifically increased 131I-induced DNA damage probably via a rise in ROS levels and produced a more prominent transcriptomic response after exposure to 131I.


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.


2018 ◽  
Vol 51 (5) ◽  
pp. 2185-2197 ◽  
Author(s):  
Lili Men ◽  
Juan Sun ◽  
Decheng Ren

Background/Aims: VCP-interacting membrane selenoprotein (VIMP), an ER resident selenoprotein, is highly expressed in β-cells, however, the role of VIMP in β-cells has not been characterized. In this study, we studied the relationship between VIMP deficiency and β-cell survival in MIN6 insulinoma cells. Methods: To determine the role of VIMP in β-cells, lentiviral VIMP shRNAs were used to knock down (KD) expression of VIMP in MIN6 cells. Cell death was quantified by propidium iodide (PI) staining followed by flow cytometric analyses using a FACS Caliber and FlowJo software. Cell apoptosis and proliferation were determined by TUNEL assay and Ki67 staining, respectively. Cell cycle was analyzed after PI staining. Results: The results show that 1) VIMP suppression induces β-cell apoptosis, which is associated with a decrease in Bcl-xL, and the β-cell apoptosis induced by VIMP suppression can be inhibited by overexpression of Bcl-xL; 2) VIMP knockdown (KD) decreases cell proliferation and G1 cell cycle arrest by accumulating p27 and decreasing E2F1; 3) VIMP KD suppresses unfolded protein response (UPR) activation by regulating the IRE1α and PERK pathways; 4) VIMP KD increases insulin secretion. Conclusion: These results suggest that VIMP may function as a novel regulator to modulate β-cell survival, proliferation, cell cycle, UPR and insulin secretion in MIN6 cells.


2019 ◽  
Vol 12 (2) ◽  
pp. 629-638
Author(s):  
N. N. Bahari ◽  
S. Y. N. Jamaludin ◽  
A. H. Jahidin ◽  
M. N. Zahary ◽  
A. B. Mohd Hilmi

The transient receptor potential vanilloid member 4 (TRPV4) is a non-selective calcium (Ca2+)-permeable channel which is widely expressed in different types of tissues including the lungs, liver, kidneys and salivary gland. TRPV4 has been shown to serve as a cellular sensor where it is involved in processes such as osmoregulation, cell volume regulation and thermoregulation. Emerging evidence suggests that TRPV4 also plays important roles in several aspects of cancer progression. Despite the reported roles of TRPV4 in several forms of cancers, the role of TRPV4 in human colorectal cancer remains largely unexplored. In the present study, we sought to establish the potential role of TRPV4 in colorectal cancer by assessing TRPV4 expression levels and investigating whether TRPV4 pharmacological modulation may alter cell proliferation, cell cycle and cell death in colorectal cancer cells. Quantitative real-time PCR analysis revealed that TRPV4 mRNA levels were significantly lower in HT-29 cells than normal colon CCD-18Co cells. However, TRPV4 mRNA was absent in HCT-116 cells. Pharmacological activation of TRPV4 with GSK1016790A significantly enhanced the proliferation of HT-29 cells while TRPV4 inhibition using RN 1734 decreased their proliferation. Increased proliferation in GSK1016790A-treated HT-29 cells was attenuated by co-treatment with RN 1734. Pharmacological modulation of TRPV4 had no effect on the cell cycle progression but promoted cell death in HT-29 cells. Taken together, these findings suggest differential TRPV4 expression levels in human colorectal cancer cells and that pharmacological modulation of TRPV4 produces distinct effects on the proliferation and induces cell death in HT-29 cells.


2007 ◽  
Vol 10 (1-2) ◽  
pp. 13-29 ◽  
Author(s):  
S MADDIKA ◽  
S ANDE ◽  
S PANIGRAHI ◽  
T PARANJOTHY ◽  
K WEGLARCZYK ◽  
...  

Genes ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 378 ◽  
Author(s):  
Carlos Camilleri-Robles ◽  
Florenci Serras ◽  
Montserrat Corominas

The GADD45 proteins are induced in response to stress and have been implicated in the regulation of several cellular functions, including DNA repair, cell cycle control, senescence, and apoptosis. In this study, we investigate the role of D-GADD45 during Drosophila development and regeneration of the wing imaginal discs. We find that higher expression of D-GADD45 results in JNK-dependent apoptosis, while its temporary expression does not have harmful effects. Moreover, D-GADD45 is required for proper regeneration of wing imaginal discs. Our findings demonstrate that a tight regulation of D-GADD45 levels is required for its correct function both, in development and during the stress response after cell death.


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