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Down-regulating cold shock protein genes impairs cancer cell survival and enhances chemosensitivity.

ABSTRACT: The microenvironment of the cancer cell is pivotal to its phenotypic regulation. One of the central components of the microenvironment is temperature. An elevation in environmental temperature has been shown to increase the cancer cell's susceptibility to chemo- and radiation therapy. The goal of the studies described here was to identify some of the pathways that are modified by a mild increase in temperature in cancer cells. Using prostate cancer cells as a model system we found that in addition to the well described and anticipated up-regulation of the heat shock family of proteins, there is a significant down-regulation of certain members of the "cold shock" family of proteins such as, RNA binding motif protein 3 (RBM3) and cold inducible RNA binding protein (CIRBP). siRNA-mediated down-regulation of the cold shock protein (CSP) encoding mRNAs dramatically attenuates cell survival in the absence of any heat application. Furthermore, we also demonstrate that knocking down the CSPs can enhance the therapeutic response of prostate cancer cells to chemotherapy. Our findings suggest that down-regulating CSPs in cancer cells may "mimic" the stress response the cells experience when exposed to heat treatment rendering them more susceptible to therapy. Thus, the pharmacological modulation of RBM3 and CIRBP may represent novel therapeutic approaches for prostate cancer.

SUBMITTER: Zeng Y

PROVIDER: S-EPMC4407561 | biostudies-other | 2009 May

REPOSITORIES: biostudies-other

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Down-regulating cold shock protein genes impairs cancer cell survival and enhances chemosensitivity.

Zeng Yu Y Kulkarni Prakash P Inoue Takahiro T Getzenberg Robert H RH

Journal of cellular biochemistry 20090501 1

The microenvironment of the cancer cell is pivotal to its phenotypic regulation. One of the central components of the microenvironment is temperature. An elevation in environmental temperature has been shown to increase the cancer cell's susceptibility to chemo- and radiation therapy. The goal of the studies described here was to identify some of the pathways that are modified by a mild increase in temperature in cancer cells. Using prostate cancer cells as a model system we found that in additi ...[more]

PMID: 19277990

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Project description:BackgroundThe regulatory roles of long non-coding RNA (lncRNA) CRNDE in temozolomide (TMZ) chemoresistance to glioblastoma multiforme (GBM) are still poorly understood. Therefore, the function, characteristics, and possible mechanism of CRNDE in TMZ-induced chemoresistance to GBM were explored.MethodsFirstly, the expression level of CRNDE in 58 cases of glioma tissue specimens and 30 cases of normal brain tissues were tested by qRT-PCR. Meanwhile, the correlation between CRNDE expression level, the clinicopathological characteristics, and survival time of patients with glioma were analyzed. Then, the CRNDE expression in various glioma cell lines was detected, and CRNDE knockdown cell models were constructed. Subsequently, to explore the effect of CRNDE on chemosensitivity to TMZ, cell viability was detected by the CCK-8 assay and IC50 values, and cell proliferation was detected by cell clone assay and EdU assay, as well as cell survival was detected by apoptosis with flow cytometry under TMZ treatment. Further, the expression of drug-resistance protein ABCG2, autophagy related proteins, and PI3K/Akt/mTOR pathway were measured by western blot or qRT-PCR in TMZ-treated glioma cells. Finally, the mouse tumor xenograft model was established and the tumor volume and weight were measured, and ABCG2 expression was conducted by immunohistochemistry assay.ResultsThe integrated results demonstrated lncRNA CRNDE was a poor prognosis factor for GBM patient, which was upregulated in patients who were resistant to TMZ, and closely associated with chemotherapeutic response status to TMZ treatment. Further, functional assays revealed that knockdown of CRNDE could notably reduce glioma cell viability and proliferation, and elevate cell apoptosis to enhance the chemosensitivity to TMZ in vitro and in vivo. Mechanistically, the depression of CRNDE could diminish the expression of LC3 II/I, Beclin1 and Atg5 and increase the p62 expression level to inhibit autophagy due to the activation of PI3K/Akt/mTOR pathway as well as highly correlated with ABCG2 expression.ConclusionsOverall, the study provided that lncRNA CRNDE is a reliable clinical predictor of outcome and prognosis and a potential biomarker for predicting TMZ treatment response in GBM by modulating the autophagy through PI3K/Akt/mTOR pathway and ABCG2 expression which may be a novel therapeutic target for regulating TMZ sensitivity to GBM.

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Down-regulating cold shock protein genes impairs cancer cell survival and enhances chemosensitivity.

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Down-regulating cold shock protein genes impairs cancer cell survival and enhances chemosensitivity.

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