Colorectal cancer (CRC) is the second leading cause of cancer-related illness worldwide and one of the most common malignancies. Therefore, colorectal cancer research and cases have gained increasing attention. Oxaliplatin (OXA) is currently used in first-line chemotherapy to treat stage III and stage IV metastatic CRC. However, patients undergoing chemotherapy often develop resistance to chemo drugs being used. Evidence has confirmed that microRNAs regulate downstream genes in cancer biology and thereby have roles related to tumor growth, proliferation, invasion, angiogenesis, and multi-drug resistance. The aim of our study is to establish whether miR-31-5p is an oncogene in human colorectal cancers that are resistant to OXA and further confirm its malignant phenotype-associated target molecule. From the results of miRNA microarray assay, we establish that miR-31-5p expression was upregulated in oxaliplatin-resistant (OR)-LoVo cells compared with parental LoVo cells. Moreover, through in vitro and in vivo experiments, we demonstrate that miR-31-5p and large tumor suppressor kinase 2 (LATS2) were inversely related and that miR-31-5p and Forkhead box C1 (FOXC1) were positively correlated in the same LoVo or OR-LoVo cells. Importantly, we reveal a novel drug-resistance mechanism in which the transcription factor FOXC1 binds to the miR-31 promoter to increase the expression of miR31-5p and regulate LATS2 expression, resulting in cancer cell resistance to OXA. These results suggest that miR-31-5p may be a novel biomarker involved in drug resistance progression in CRC patients. Moreover, the FOXC1/miR31-5p/LATS2 drug-resistance mechanism provides new treatment strategies for CRC in clinical trials.

Background: Colorectal cancer (CRC) remains a leading cause of cancer-related morbidity and mortality in both sexes globally. This is not unconnected with the heterogeneity and plasticity of CRC stem cells (CRC-SCs) which stealthily exploit the niche-related and (epi)genetic factors to facilitate metastasis, chemoresistance, tumor recurrence, and disease progression. Despite the accumulating evidence of the role of dysregulated microRNAs in malignancies, the therapeutic efficacy of pharmacological-targeting of CRC-SC-associated microRNAs is relatively under-explored. Experimental approach: In this present study, we employed relatively new bioinformatics approaches, analyses of microarray data, Western blot, real-time polymerase chain reaction (RT-PCR), and functional assays to show that hsa-miR-324-5p expression is significantly suppressed in CRC cells, and inversely correlates with the aberrant expression of SOD2. Results: This converse hsa-miR-324-5p/SOD2 relationship is associated with enhanced oncogenicity, which is effectively inhibited by 4-acetylantroquinonol B (4-AAQB), as evidenced by inhibited cell viability and proliferation, as well as attenuated migration, invasion, and clonogenicity in 4-AAQB-treated DLD1 and HCT116 cells. Interestingly, 4-AAQB did not affect the viability and proliferation of normal colon cells. We also showed that 4-AAQB-induced re-expression of hsa-miR-324-5p, akin to short-interfering RNA, reduced SOD2 expression, correlates with the concurrent down-regulation of SOD2, N-cadherin, vimentin, c-Myc, and BcL-xL2, with concomitant up-regulation of E-cadherin and BAX2 proteins. Enhanced expression of hsa-miR-324-5p in the CRC cells suppressed their tumorigenicity in vitro and in vivo. Additionally, 4-AAQB synergistically potentiates the FOLFOX (folinate (leucovorin), fluorouracil (5FU), and oxaliplatin) anticancer effect by eliciting the re-expression of SOD2-suppressed hsa-miR-324, and inhibiting SOD2-mediated tumorigenicity. Conclusion: Our findings highlight the pre-clinical anti-CSC efficacy of 4-AAQB, with or without FOLFOX in CRC, and suggest a potential novel therapeutic strategy for CRC patients.

Background: Hepatocellular carcinoma (HCC) remains an aggressive malignancy with a poor prognosis and a leading cause of cancer-related mortality globally. Cumulative evidence suggests critical roles for endoplasmic reticulum (ER) stress and unfolded protein response (UPR) in chronic liver diseases. However, the role of ER stress in HCC pathogenesis, aggressiveness and therapy response remains unclear and understudied. Objectives: Against this background, the present study evaluated the therapeutic efficacy and feasibility of notopterol (NOT), a furanocoumarin and principal component of Notopterygium incisum, in the modulation of ER stress and cancer stemness, and the subsequent effect on liver oncogenicity. Methods: An array of biomolecular methods including Western blot, drug cytotoxicity, cell motility, immunofluorescence, colony and tumorsphere formation, flow-cytometric mitochondrial function, GSH/GSSG ratio, and tumor xenograft ex vivo assays were used in the study. Results: Herein, we demonstrated that NOT significantly suppresses the viability, migration, and invasion capacity of the human HCC HepJ5 and Mahlavu cell lines by disrupting ATF4 expression, inhibiting JAK2 activation, and downregulating the GPX1 and SOD1 expression in vitro. NOT also markedly suppressed the expression of vimentin (VIM), snail, b-catenin, and N-cadherin in the HCC cells, dose-dependently. Treatment with NOT significantly attenuated cancer stem cells (CSCs)-like phenotypes, namely colony and tumorsphere formation, with the concomitant downregulation of stemness markers OCT4, SOX2, CD133, and upregulated PARP-1 cleavage, dose-dependently. We also demonstrated that NOT anticancer activity was strongly associated with increased cellular reactive oxidative stress (ROS) but, conversely, reduced mitochondrial membrane potential and function in the HepJ5 and Mahlavu cells in vitro. Our tumor xenograft studies showed that compared with sorafenib, NOT elicited greater tumor growth suppression without adverse changes in mice body weights. Compared with the untreated control and sorafenib-treated mice, NOT-treated mice exhibited markedly greater apoptosis ex vivo, and this was associated with the co-suppression of stemness and drug-resistance markers OCT4, SOX2, ALDH1, and the upregulation of endoplasmic reticulum stress and oxidative stress factors PERK and CHOP. Conclusions: In summary, we demonstrated for the first time that NOT exhibits strong anticancer activity via the suppression of cancer stemness, enhanced endoplasmic reticulum stress and increased oxidative stress thus projecting NOT as a potentially effective therapeutic agent against HCC.

Background: Neoadjuvant chemoradiation therapy (NCRT) followed by surgery is the standard treatment for locally advanced rectal cancer (LARC); approximately 80% of patients do not achieve complete response. Identifying prognostic factors predictive of survival in these patients to guide further management is needed. The intratumoural lymphocytic response (ILR), peritumoural lymphocytic reaction (PLR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PtLR) are correlated with the tumour microenvironment and cancer-related systemic inflammation. This study aimed to explore the ability of the ILR, PLR, NLR, and PtLR to predict survival in LARC patients without a complete response to NCRT. Methods: Sixty-nine patients who underwent NCRT and surgery were retrospectively reviewed. The ILR and PLR were assessed in surgical specimens, and the NLR and PtLR were calculated using pre- and post-NCRT blood count data. The Kaplan–Meier method and Cox regression analyses were performed for survival analysis. Results: A high PLR and high post-NCRT NLR and PtLR were significantly associated with better prognosis. Lymphovascular invasion (LVI), post-NCRT neutrophil count, and lymphocyte count were significant predictors of overall survival. LVI and the PLR were independent predictors of disease-free survival. Conclusions: NCRT-induced local and systemic immune responses are favourable prognostic predictors in LARC patients without complete response to NCRT.