IC50 Of Oxaliplatin Research Articles

LINC00894 targets Annexin A2 to regulate oxaliplatin resistance in hepatocellular carcinoma: ANXA2 protein function

To investigate the role of LINC00894 in oxaliplatin chemoresistance of hepatocellular carcinoma (HCC) and its mechanisms. The oxaliplatin-resistant HCC cell lines were established. IC50 of oxaliplatin was calculated by CCK-8 assay. Cell viability was detected using clonal formation experiment, while cell apoptosis was accessed by flow cytometry. RNA binding protein immunoprecipitation and RNA pull-down were performed to explore the interaction of LINC00894 and ANXA2. The expressions of RNA and protein were tested by qRT-PCR and western blot respectively. Tumor xenograft was performed to detect the effect of LINC00894 in vivo. The expression of ki67 was evaluated by immunohistochemistry staining. LINC00894 was overexpressed in HCC cells resistant to oxaliplatin. Elevated LINC00894 promoted HCC cells resistance to oxaliplatin, whereas silence of LINC00894 improved HCC sensitivity to oxaliplatin. LINC00894 could bind to the ANXA2 protein, enhanced the stability of the ANXA2 protein and reduced its ubiquitination. Furthermore, LINC00894 modulated HCC resistance to oxaliplatin both in vitro and in vivo by targeting the ANXA2 protein.LINC00894 enhanced the stability of ANXA2 protein and attenuated its ubiquitination by interacting with it, thereby promoting oxaliplatin resistance in HCC. Our findings contributed to understanding the role of these mechanisms in the process of oxaliplatin resistance in HCC.

Elevated TUBA1A Might Indicate the Clinical Outcomes of Patients with Gastric Cancer, Being Associated with the Infiltration of Macrophages in the Tumor Immune Microenvironment.

TUBA1A belongs to the tubulin superfamily, and its role in gastric cancer (GC) remains unclear. This study assessed the expression and effect of TUBA1A in GC, as well as its association with survival and clinicopathological features. Gene set enrichment analysis (GSEA) results revealed that high TUBA1A expression was associated with multiple pathways, including those that contributed to the infiltration of macrophages in the tumor microenvironment. Since increased infiltration of macrophages can lead to oxaliplatin resistance, we analyzed the association between TUBA1A, the infiltration of macrophages to the tumor microenvironment, and the inhibitory concentration 50% (IC50) of oxaliplatin. In addition, we analyzed the possible epigenetic regulation mechanism. A total of 1,881 samples, including 1,618 patients with GC and 263 normal samples, were examined. The associations between clinicopathological features and TUBA1A were assessed by chi-square test, survival was assessed by Kaplan-Meier analysis, and gene set enrichment analysis (GSEA) was performed to explore the potential mechanisms. The associations between TUBA1A and immune infiltration of M0-, M1-, and M2- polarized macrophages were examined by applying deconvolution's quantification and Pearson's correlation analysis. The association of TUBA1A with the IC50 of oxaliplatin was analyzed by Pearson correlation test. The mechanisms of TUBA1A dysregulation were studied by analyzing methylation data. A single-cell TUBA1A mRNA expression map of the stomach was drawn from the analysis of stomach single-cell RNA sequencing data that included more than 13,000 single cells of 17 stomach cell types. TUBA1A expression was elevated in GC (p<0.01) and indicated poorer overall survival (p<0.001), first progression survival (p<0.001), and post-progression survival (p<0.01). High TUBA1A expression was significantly correlated with more aggressive clinicopathological features of GC patients (p<0.001). Elevated TUBA1A contributes to the infiltration of macrophages to the tumor microenvironment (p<0.001) and increased the IC50 of oxaliplatin in vitro (p<0.05), while hypomethylation was shown to contribute to the upregulation of TUBA1A (p<0.05). TUBA1A might be a potential prognostic marker and therapeutic target in GC. TUBA1A is significantly associated with the infiltration of M2-polarized macrophages in GC, and the IC50 of oxaliplatin. Hypomethylation contributes to the upregulation of TUBA1A in GC.

Abstract 1520: RAB31 triggers oxaliplatin resistance in colorectal cancer via epithelial-mesenchymal transition

Abstract Colorectal tumorigenesis during Epithelial-Mesenchymal transition (EMT) is associated with cancer metastasis and drug resistance. The small G-proteins family has been implicated in the regulation of cell cytoskeleton, cell movement, and vesicle transport. Small G-proteins family is divided into five main families. The Rab protein family is a member of the Ras superfamily of small G-proteins. We analyzed all probes of the Rab family members from microarray datasets and RNA-sequencing. We further calculated the EMT scores by using an algorithm. Our results showed that the RAB31 expression levels of the three probes are positively correlated with EMT score (Pearson rho=0.72, 0.71 and 0.68, respectively). Compared with other family members, RAB31 had most significantly value in colorectal cancer cell lines. We established several two-way model with cDNA and shRNAs of RAB31, respectively. Furthermore, we observed that the expression of epithelial type marker CDH1 was inhibited, and mesenchymal type markers SNAI1 and SNAI2 were upregulated in RAB31 overexpression models. Moreover, we found that the protein level of RAB31 was correlated with several clinicopathological parameters (N status, M status) and disease-free survival in tissue arrays through immunohistochemistry staining. According to The Cancer Genome Atlas Program (TCGA) and online meta-database, high RNA level of RAB31 was consistent in colorectal cancer (HR=1.38, n=466 and HR=1.29, n=482) and correlated with poor prognosis of patients. In addition, we identified that RAB31 may associated with IC50 of oxaliplatin and EGFR trafficking. We concluded that RAB31 regulates the sensitivity of oxaliplatin, an additional chemotherapy strategy and an independent prognostic factor for colorectal cancer. Citation Format: Chi-Long Chen, Yu-Chan Chang, Michael Hsiao. RAB31 triggers oxaliplatin resistance in colorectal cancer via epithelial-mesenchymal transition [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1520.

Effect of small interference RNA silenced S100A4 protein in human gastric carcinoma cells on proliferation, apoptosis and chemotherapy sensitivity in vitro

Objective To study the application of small interfering RNA silencing S100A4 protein in human gastric cancer cell BGC-823 proliferation, apoptosis and the effect of chemotherapy sensitivity. Methods Human gastric carcinoma cell line BGC - 823 transfection siRNA, RT-PCR detected the changes of mRNA after transfection. Groups divided into interference group, negative control group and normal control group. MTT test determined different concentrations of oxaliplatin in gastric cancer cells and calculated IC50,then draw cell growth curve, TUNEL method to detect apoptosis, RT-PCR tested each cell mRNA changed, Western blot detected the change of the S100A4 protein. All data analysis by SPSS17.0, t test applied, RT-PCR and Western blot results analysis by SPSS17.0, comparing multiple samples by using single factor analysis of variance and LSD test. P<0.05 was statistically significant. Results RT-PCR results showed that BGC- 823 cell transfection, S100A4mRNA expression quantity respectively after 48 hours: (0.674±0.011), (0.652±0.021), (0.345±0.040), the interference group and normal control group were statistically significant (P=0.012, P 0.380); Western blot results showed BGC - 823 cell transfection S100A4 expression significantly lowered respectively after 48 hours, there were (0.654 ± 0.025), (0.642±0.014), (0.317±0.061), the interference group and normal control group was statistically significant (P=0.01, P 0.341). After S100A4-siRNA transfection, gastric carcinoma BGC-823 cell proliferation decreased, TUNEL method showed obviously increase apoptosis, MTT showed that IC50 of oxaliplatin was 56.31 μmol/L, after transfection, IC50 was 0.654 μmol/L. Conclusions This study showed that the siRNA silence S100A4 protein inhibit gastric cancer cell proliferation, induced apoptosis and improved chemotherapy sensitivity of oxaliplatin. S100A4 might be prompt targets for the treatment of gastric carcinoma. Key words: Gastric carcinoma; siRNA-S100A4; Cell proliferation; Apoptosis; Chemotherapy sensitivity

Abstract 4350: Low frequencies of SF3B1 mutations indicate SF3B1 inhibitor as a novel moleculartargeted drug for colorectal cancer.

Abstract Purpose: FR901464 (FR) is an antitumor agent that specifically binds to and inhibits the function of splicing factor 3B subunit 1 (SF3B1). Higher frequencies of SF3B1 gene mutations and their relevance to cancer progression have been shown in studies of hematological malignancies. We assessed the frequencies of SF3B1 gene mutations in colorectal cancer (CRC) and the correlation of SF3B1 mutations and FR sensitivity in CRC. Experimental Design: We measured FR sensitivity in CRC cell lines to establish FR-resistant clones and performed DNA sequencing of all 25 SF3B1 exons in nine CRC cell lines, FR-resistant clones, and 16 CRC patients. On the basis our results, we performed further DNA sequencing in 80 CRC patients. Results: The FR IC50 values in all CRC cell lines were &amp;lt; 1ng/ml. Six FR-resistant clones were established: three from DLD1, two from HCT116, and one from LoVo cells. The FR IC50 of the FR-resistant clones was &amp;gt; 500-fold greater than that of their parental cells, although the IC50 of oxaliplatin or 5-fuluorouracil were the same. We found nonsense mutations in exon 10 of DLD1 cells and no significant mutations in the other samples. All the FR-resistant clones had the missense mutations in codon 1073 of exon 22. We found no mutation in exons 10, 22, and 12-15, which were previously reported in hematological malignancies in 80 CRC patients. Conclusion: Our data indicated the usefulness of the SF3B1 inhibitor as a novel molecular targeted drug for CRC and the other malignancies without codon 1073 mutations. Citation Format: Tomoki Yamano, Hidenori Nakajima, Satoshi Tsuda, Shuji Kubo, Mie Hamanaka, Masayoshi Kobayashi, Daisuke Yamagishi, Takashi Kuno, Kiyoshi Tsukamoto, Astuko Tamamoto, Masafumi Noda, Nagahide Matsubara, Dave SB Hoon, Naohiro Tomita. Low frequencies of SF3B1 mutations indicate SF3B1 inhibitor as a novel moleculartargeted drug for colorectal cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4350. doi:10.1158/1538-7445.AM2013-4350

Effect of trastuzumab on telomere-related proteins and the relationship to the sensitivity of HER2-amplified human gastric cancer cells to oxaliplatin and cisplatin.

53 Background: HER2 amplification occurs in about 20% of gastric cancers, and trastuzumab in combination with cisplatin based chemotherapy has been reported to improve oncological outcomes in gastric and gastro-oesophageal junction cancer with HER2 gene amplification. The aim of this study was to evaluate the potentially useful combined antitumor efficacy of trastuzumab and platinum agents in gastric cancer cells and to elucidate further the mechanisms possibly involved in the interaction between the trastuzumab and platinum agents. Methods: Gene expression was determined by using real-time quantitative PCR in gastric cancer cell lines. The chemosensitivity of gastric cancer cells to platinum agents and the apoptotic effect of drugs in vitro were evaluated using cellTiter 96 Aqueous One Solution Cell Proliferation Assay kit and double staining with both Annexin-V-FITC and PI, respectively. Results: Treatment with 1.0μg/ml trastuzumab for 48h could significantly increase sensitivity of oxaliplatin or cisplatin in HER2 amplified gastric cancer cells, and the IC50 of oxaliplatin and cisplatin were reduced to about 3.29 times and 6.91 times, respectively. Apoptosis analysis also indicated that trastuzumab significantly increased both oxaliplatin and cisplatin-induced apoptosis in NCI-N87 cells. Analysis of telomere-related genes revealed that trastuzumab singly and pretreatment with trastuzumab for 48h followed by oxaliplatin or cisplatin for another 48h could significantly downregulate the mRNA expression of TPP1, TRF1, TRF2, TRF2IP, POT1 and TIN2 genes. Conclusions: Our results describe the potential role of low dose trastuzumab to increase sensitivity of oxaliplatin and cisplatin in HER2 amplified gastric cancer cells, which may be partially through downregulating the expression levels of telomere-related genes.