Suresh Singh Yadav1, Manoj Kumar2, Akhil Varshney3, Pramod Kumar Yadava4. 1. Weizmann Institute of Science, Herzl St 234, Rehovot 76100, Israel. 2. Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India. 3. Centre for Advanced Vision Science, University of Virginia, 415 Lane Road, Charlottesville, VA 22908, USA. 4. Applied Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India. Electronic address: pky0200@mail.jnu.ac.in.
Abstract
AIMS: Insensitivity of cancer cells to therapeutic drugs is the most daunting challenge in cancer treatment. The mechanism of developing chemo-resistance is only partly understood to date. In continuation of some earlier reports, we hypothesize that KLF4, a key transcription factors that also has a crucial role in maintaining the stemness in cancer cells, may offer a basis for chemo-resistance. MAIN METHODS: Sensitivity of cells to cisplatin was analyzed by cell proliferation, colony formation, and cell growth assay. Cell cycle analysis and immunophenotyping were used to measure cell cycle arrest and level of reactive oxygen species respectively. Immunoblotting was used to analyze the change in expression hTERT and HMGB1 involved in KLF4 mediated cisplatin resistance. KEY FINDINGS: We found that KLF4 expression sensitizes cancer cell to cisplatin cytotoxicity. Further, KLF4 promotes the cisplatin-mediated G2/M cell cycle arrest while KLF4 knocked down induces cisplatin-mediated S-phase arrest compared to control. Decreased level of reactive oxygen species (ROS) in cisplatin-treated and KLF4 knocked down HCT-15 cells compared to vector control, accounting for increased cell survival. Immuno-blotting showed that KLF4 positively regulates expression of the survival proteins hTERT and HMGB1 while in presence of cisplatin, expression of HMGB1 and hTERT is negatively regulated by KLF4. SIGNIFICANCE: This study suggests the involvement of KLF4-HMGB1/hTERT signaling in offering the basis for chemo-resistance in colon cancer cells and KLF4 overexpression as a probable strategy for sensitizing drug-resistant cancer cells to chemotherapy. The present study opens up new avenues for cancer research and therapeutics.
AIMS: Insensitivity of cancer cells to therapeutic drugs is the most daunting challenge in cancer treatment. The mechanism of developing chemo-resistance is only partly understood to date. In continuation of some earlier reports, we hypothesize that KLF4, a key transcription factors that also has a crucial role in maintaining the stemness in cancer cells, may offer a basis for chemo-resistance. MAIN METHODS: Sensitivity of cells to cisplatin was analyzed by cell proliferation, colony formation, and cell growth assay. Cell cycle analysis and immunophenotyping were used to measure cell cycle arrest and level of reactive oxygen species respectively. Immunoblotting was used to analyze the change in expression hTERT and HMGB1 involved in KLF4 mediated cisplatin resistance. KEY FINDINGS: We found that KLF4 expression sensitizes cancer cell to cisplatincytotoxicity. Further, KLF4 promotes the cisplatin-mediated G2/M cell cycle arrest while KLF4 knocked down induces cisplatin-mediated S-phase arrest compared to control. Decreased level of reactive oxygen species (ROS) in cisplatin-treated and KLF4 knocked down HCT-15 cells compared to vector control, accounting for increased cell survival. Immuno-blotting showed that KLF4 positively regulates expression of the survival proteins hTERT and HMGB1 while in presence of cisplatin, expression of HMGB1 and hTERT is negatively regulated by KLF4. SIGNIFICANCE: This study suggests the involvement of KLF4-HMGB1/hTERT signaling in offering the basis for chemo-resistance in colon cancer cells and KLF4 overexpression as a probable strategy for sensitizing drug-resistant cancer cells to chemotherapy. The present study opens up new avenues for cancer research and therapeutics.
Authors: Agnieszka Taracha-Wisniewska; Grzegorz Kotarba; Sebastian Dworkin; Tomasz Wilanowski Journal: Int J Mol Sci Date: 2020-11-22 Impact factor: 5.923