Dataset Information

Expression of asporin reprograms cancer cells to acquire resistance to oxidative stress.

ABSTRACT: Asporin (ASPN), a small leucine-rich proteoglycan expressed predominantly by cancer associated fibroblasts (CAFs), plays a pivotal role in tumor progression. ASPN is also expressed by some cancer cells, but its biological significance is unclear. Here, we investigated the effects of ASPN expression in gastric cancer cells. Overexpression of ASPN in 2 gastric cancer cell lines, HSC-43 and 44As3, led to increased migration and invasion capacity, accompanied by induction of CD44 expression and activation of Rac1 and MMP9. ASPN expression increased resistance of HSC-43 cells to oxidative stress by reducing the amount of mitochondrial reactive oxygen species. ASPN induced expression of the transcription factor HIF1? and upregulated lactate dehydrogenase A (LDHA) and PDH-E1?, suggesting that ASPN reprograms HSC-43 cells to undergo anaerobic glycolysis and suppresses ROS generation in mitochondria, which has been observed in another cell line HSC-44PE. By contrast, 44As3 cells expressed high levels of HIF1? in response to oxidant stress and escaped apoptosis regardless of ASPN expression. Examination of xenografts in the gastric wall of ASPN^-/- mice revealed that growth of HSC-43 tumors with increased micro blood vessel density was significantly accelerated by ASPN; however, ASPN increased the invasion depth of both HSC-43 and 44As3 tumors. These results suggest that ASPN has 2 distinct effects on cancer cells: HIF1?-mediated resistance to oxidative stress via reprogramming of glucose metabolism, and activation of CD44-Rac1 and MMP9 to promote cell migration and invasion. Therefore, ASPN may be a new therapeutic target in tumor fibroblasts and cancer cells in some gastric carcinomas.

SUBMITTER: Sasaki Y

PROVIDER: S-EPMC7935789 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Objective: Redox adaptation plays a critical role in cancer cells’ drug tolerance and sensitivity. The antioxidative response is induced by nuclear factor erythroid 2-related factor 2 (Nrf2), which triggers the transcriptional activation of genes related to chemosensitivity, glutathione synthesis, and cell protection. Although Nestin1 is known to regulate cellular redox homeostasis by regulating Nrf2 in lung cancer cells, its regulatory effect on the antioxidative state of bladder cancer (BC) cells remains unclear. Methods: The oxidative stress levels in two cisplatin-treated BC cell lines (T24 and J82) were examined using 2’,7’-dichlorofluorescin diacetate staining and real-time quantitative reverse transcription-PCR (RT-qPCR) assays. The cell viability, growth, and apoptosis were determined using CCK-8, colony formation, and flow cytometric assays, respectively. The mRNA and protein levels of Nestin1, Nrf2, and several antioxidant enzymes were quantified using RT-qPCR and western blot assays. A mouse xenograft model was used to determine the effect of Nestin1 on the T24 tumor growth in vivo. Results: Cisplatin treatment induced reactive oxygen species (ROS) generation and antioxidative damage in the T24 and J82 cells, reducing their viability and growth and triggering their apoptosis. Moreover, the Nestin1 and Nrf2 protein levels were enhanced in both treated cell lines. Loss- and gain-of-function assays indicated that Nestin1 expression was positively correlated with the Nrf2 protein expression in the BC cells. Nestin1 overexpression reduced the ROS generation, alleviated the redox disorder, promoted cell viability, and reduced apoptosis, but its silencing had the opposite effects. Importantly, Nestin1 overexpression enhanced the chemoresistance of BC cells to cisplatin in vivo, but its knockdown improved the chemosensitivity of the cells and increased their apoptosis. Conclusion: These results provide a theoretical basis for further targeting the transcription factors, including Nestin1 and Nrf2, in the treatment of BC with cisplatin.

Project description:BACKGROUND: Anti-mitotic compounds (microtubule de-stabilizers) such as vincristine and vinblastine have been shown clinically successful in treating various cancers. However, development of drug-resistance cells limits their efficacies in clinical situations. Therefore, experiments were performed to determine possible drug resistance mechanisms related to the application of anti-mitotic cancer therapy. PRINCIPAL FINDINGS: A KB-derived microtubule de-stabilizer-resistant KB-L30 cancer cell line was generated for this study. KB-L30 cells showed cross-resistance to various microtubule de-stabilizers including BPR0L075, vincristine and colchicine through multiple-drug resistant (MDR)-independent mechanisms. Surprisingly, KB-L30 cells showed hyper-sensitivity to the microtubule-stabilizer, paclitaxel. Results of the RT-PCR analysis revealed that expression of both class II and III ?-tubulin was down-regulated in KB-L30 cells as compared to its parental KB cancer cells. In addition, DNA sequencing analysis revealed six novel mutation sites present in exon four of the ?I-tubulin gene. Computational modeling indicated that a direct relationship exists between ?I-tubulin mutations and alteration in the microtubule assembly and dynamic instability in KB-L30 cells and this predicted model was supported by an increased microtubule assembly and reduced microtubule dynamic instability in KB-L30 cells, as shown by Western blot analysis. CONCLUSIONS AND SIGNIFICANCE: Our study demonstrated that these novel mutations in exon four of the ?I-tubulin induced resistance to microtubule de-stabilizers and hyper-sensitivity to microtubule stabilizer through an alteration in the microtubule assembly and dynamics in cancer cells. Importantly, the current study reveals that cancer cells may acquire drug resistance ability to anti-mitotic compounds through multiple changes in the microtubule networks. This study further provided molecular information in drug selection for patients with specific tubulin mutations.

Project description:BackgroundAscorbic acid demonstrates a cytotoxic effect by generating hydrogen peroxide, a reactive oxygen species (ROS) involved in oxidative cell stress. A panel of eleven human cancer cell lines, glioblastoma and carcinoma, were exposed to serial dilutions of ascorbic acid (5-100 mmol/L). The purpose of this study was to analyse the impact of catalase, an important hydrogen peroxide-detoxifying enzyme, on the resistance of cancer cells to ascorbic acid mediated oxidative stress.MethodsEffective concentration (EC(50)) values, which indicate the concentration of ascorbic acid that reduced the number of viable cells by 50%, were detected with the crystal violet assay. The level of intracellular catalase protein and enzyme activity was determined. Expression of catalase was silenced by catalase-specific short hairpin RNA (sh-RNA) in BT-20 breast carcinoma cells. Oxidative cell stress induced apoptosis was measured by a caspase luminescent assay.ResultsThe tested human cancer cell lines demonstrated obvious differences in their resistance to ascorbic acid mediated oxidative cell stress. Forty-five percent of the cell lines had an EC(50) > 20 mmol/L and fifty-five percent had an EC(50) < 20 mmol/L. With an EC(50) of 2.6-5.5 mmol/L, glioblastoma cells were the most susceptible cancer cell lines analysed in this study. A correlation between catalase activity and the susceptibility to ascorbic acid was observed. To study the possible protective role of catalase on the resistance of cancer cells to oxidative cell stress, the expression of catalase in the breast carcinoma cell line BT-20, which cells were highly resistant to the exposure to ascorbic acid (EC(50): 94,9 mmol/L), was silenced with specific sh-RNA. The effect was that catalase-silenced BT-20 cells (BT-20 KD-CAT) became more susceptible to high concentrations of ascorbic acid (50 and 100 mmol/L).ConclusionsFifty-five percent of the human cancer cell lines tested were unable to protect themselves against oxidative stress mediated by ascorbic acid induced hydrogen peroxide production. The antioxidative enzyme catalase is important to protect cancer cells against cytotoxic hydrogen peroxide. Silenced catalase expression increased the susceptibility of the formerly resistant cancer cell line BT-20 to oxidative stress.

Dataset Information

Expression of asporin reprograms cancer cells to acquire resistance to oxidative stress.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets