CHK1 Inhibition Overcomes Gemcitabine Resistance in Non-Small Cell Lung Cancer Cell A549

Abstract

The purpose of the study is mainly to investigate the role of CHK1 in gemcitabine-resistant lung cancer cell line A549. The mRNA and protein levels of genes were analyzed by RT-qPCR and Western blot, respectively. Cell viability was detected by CCK-8 assay and clone formation assay. The detection of the cell cycle was used by Annexin V-PE/7-AAD apoptosis detection kit. Analysis of DNA damage by immunofluorescence and alkaline comet assay. The results showed that inhibition of CHK1 and gemcitabine combination significantly reduced the proliferation ability of the two cell lines. We also revealed the degradation of full-length PARP and reduced Bcl-2/Bax ratio on increased apoptosis. Inhibition of CHK1 expression leads to DNA damage, induces phosphorylation of γ-H2AX, and affects the repair of homologous recombination ability through Rad51. Mechanistically, gemcitabine increased phosphorylation-ATR and phosphorylation-CHK1, indicating activation of the DNA repair system and ATR-CHK1-CDC25A pathway. Inhibition of CHK1 resulted in increased synthesis of CDK2/Cyclin A2 and CDK2/Cyclin E1 complexes, and more cells entered the subsequent cell cycle, leading to S phase arrest and mitotic catastrophe. We identified inhibition of CHK1 as a potential treatment for NSCLC and confirmed that inhibition of this kinase could overcome acquired gemcitabine resistance.

CHEK1 and GFPT1 as Potential Blood-Based Biomarkers for Colorectal Cancer

“…The inclusion criteria were colorectal adenoma and colorectal adenocarcinoma patients with complete clinical data in their medical records, and have appointments and suggested by the colorectal surgeon (co-researcher).The exclusion criteria were as follows: i) patients clinically suspected to have colorectal adenocarcinoma associated with inflammatory bowel disease; ii) patients with metastasized cancer originated from other types of cancer; iii) patients with insufficient clinical data in their medical records; iv) patients who do not have follow-up consultation at Hospital Sultanah Nur Zahirah, are bed-bounded or reported to be highly expressed in breast, lung, and CRC. (7,(15)(16)(17) The GFPT1 gene encodes for the GFAT1 enzyme which mainly regulates the Hexosamine Biosynthetic Pathway (HBP) which is linked to disease and may be used as a therapeutic target. (18) GFAT1/GFPT1 was proven to be highly expressed in different types of cancer such as pancreatic, hepatocellular, and cervical cancer.…”