Metformin Suppresses Stemness of Non-Small-Cell Lung Cancer Induced by Paclitaxel through FOXO3a.

Cancer stem cells (CSCs) play a pivotal role in drug resistance and metastasis. Among the key players, Forkhead box O3a (FOXO3a) acts as a tumor suppressor. This study aimed to unravel the role of FOXO3a in mediating the inhibitory effect of metformin on cancer stemness derived from paclitaxel (PTX)-resistant non-small-cell lung cancer (NSCLC) cells. We showed that CSC-like features were acquired by the chronic induction of resistance to PTX, concurrently with inactivation of FOXO3a. In line with this, knockdown of FOXO3a in PTX-sensitive cells led to changes toward stemness, while overexpression of FOXO3a in PTX-resistant cells mitigated stemness in vitro and remarkably curbed the tumorigenesis of NSCLC/PTX cells in vivo. Furthermore, metformin suppressed the self-renewal ability of PTX-resistant cells, reduced the expression of stemness-related markers (c-MYC, Oct4, Nanog and Notch), and upregulated FOXO3a, events concomitant with the activation of AMP-activated protein kinase (AMPK). All these changes were recapitulated by silencing FOXO3a in PTX-sensitive cells. Intriguingly, the introduction of the AMPK dominant negative mutant offset the inhibitory effect of metformin on the stemness of PTX-resistant cells. In addition, FOXO3a levels were elevated by the treatment of PTX-resistant cells with MK2206 (an Akt inhibitor) and U0126 (a MEK inhibitor). Collectively, our findings indicate that metformin exerts its effect on FOXO3a through the activation of AMPK and the inhibition of protein kinase B (Akt) and MAPK/extracellular signal-regulated kinase (MEK), culminating in the suppression of stemness in paclitaxel-resistant NSCLC cells.

PLOD3 is Upregulated in Gastric Cancer and Correlated with Clinicopathologic Characteristics.

BACKGROUND: Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3 (PLOD3) has been proven to be involved in various human cancers; however, the function of PLOD3 in gastric cancer (GC) remains unclear. In this study, the role of PLOD3 in GC was evaluated. METHODS: The expression of PLOD3 in GC tissues and normal tissues was predicted by The Cancer Genome Atlas (TCGA). The kmplot online tool was performed to evaluate the impact of PLOD3 expression on GC patients' survival. Real-time PCR was conducted to verify PLOD3 expression in our own clinical samples and GC cells. The Cell Counting Kit-8 and the colony formation assay were used to detect GC cell proliferation ability. RESULTS: PLOD3 was upregulated in human GC tissues (compared to adjacent normal tissues, p < 0.001) and GC cells. High expression of PLOD3 was significantly correlated with larger tumor size (p = 0.007) and poor prognosis. Inhibition of PLOD3 could suppress cell proliferation in GC. CONCLUSIONS: These results revealed that PLOD3 may promote the progression of GC.

Arsenic Trioxide Combining Leflunomide Activates Nrf2-ARE-HO-1 Signaling Pathway and Protects Heart Xenografts.

OBJECTIVE: To investigate the molecular mechanisms underlying the effects of arsenic trioxide (As2O3) in combination with leflunomide on the hamster-to-rat heart xenotransplant. METHODS: Transplantation of LVG hamster hearts to Lewis rats was performed by anastomosis of vessels in the neck using end-to-end anastomosis with a non-suture cuff technique. Four groups of recipient rats (n=6 in each) were treated with normal saline (control), As2O3 [5 mg/(kg·day) intraperitoneally], leflunomide [5 mg/(kg·d) orally], or leflunomide [5 mg/(kg·d)+As2O3 [5 mg/(kg·d)] in combination. Donor hearts and/or rat spleens were harvested and analyzed 4 days after transplantation. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis were performed to detect the expression of the nuclear factor erythroid-derived factor 2-related factor (Nrf2) and its target gene heme oxygenase-1 (HO-1), Treg cell marker fork-head Box P3 (FOXP3), apoptosis-associated proteins Bcl-2, Bax, and cleaved caspase-3. Immunohistochemical staining was used to detect the levels of inflammatory natural killer cell and macrophage infiltration, intercellular cell adhesion molecule-1 (ICAM-1) and complement C3. RESULTS: Expression of Nrf2-ARE-HO-1 signaling pathway was upregulated in heart xenografts in rats treated with As2O3 plus leflunomide compared with control rats or rats treated with either drug alone (P<0.01), and this was accompanied by an increased Treg cells in the recipient rat spleen (P<0.01). In contrast, the expressions of Bax, cleaved caspase-3, ICAM-1, and complement C3, and infiltration of inflammatory cells in the xenografts were inhibited by As2O3 plus leflunomide treatment (P<0.01). CONCLUSION: Combination treatment with As2O3 and leflunomide protected hamster heart-xenografts in recipient rats.

Comparison of different chemoradiotherapy regimens for the preoperative treatment in patients with locally advanced rectal cancer: a network meta-analysis.

BACKGROUND: The efficacy of different neoadjuvant chemoradiotherapy regimens on locally advanced rectal cancer (LARC) remains confusing. We evaluated them together via a network meta-analysis in terms of survival benefits to find the optimal treatment. METHODS: We searched, EMBASE, Cochrane Central Register of Controlled Trials and the ClinicalTrials website according to the selection criteria for eligible publications before Oct 25, 2019. Pathological complete response rate (pCR), disease-free survival (DFS), and overall survival (OS) were analyzed based on Bayesian methods in the meta-analysis. RESULTS: Twenty-five articles containing 7,142 participants and 12 preoperative regimens were analyzed. In terms of pCR, radiation therapy plus 5-fluorouracil (RT+5-Fu), RT plus capecitabine (RT+CAPE), RT plus 5-fluorouracil and oxaliplatin (RT+FOLFOX), RT plus capecitabine and oxaliplatin (RT+XELOX), and RT plus S-1 and irinotecan (RT+IS) were better than RT alone [odds ratio (OR) =2.66, 95% credible interval [CrI], 1.38-5.01; OR =3.11, 95% CrI: 1.33-6.98; OR =4.03, 95% CrI: 1.77-9.47; OR =4.22, 95% CrI: 1.60-10.87; OR =4.55, 95% CrI: 1.11-18.88, respectively] and RT+FOLFOX and RT+XELOX were superior to FOLFOX (OR =4.58, 95% CrI: 1.57-14.19; OR =4.81, 95% CrI: 1.20-18.73), too. Benefits could be seen on comparing RT+CAPE, RT+FOLFOX, and RT+XELOX with RT (OR =0.84, 95% CrI: 0.73-0.97; OR =0.88, 95% CrI: 0.80-0.97; OR =0.79, 95% CrI: 0.66-0.95, respectively) in DFS. RT+XELOX seemed to have better effects on OS compared than RT+5-Fu and RT+CAPE (OR =0.78, 95% CrI: 0.61-1.00; OR =0.86, 95% CrI: 0.74-1.00, respectively). Moreover, according to surface under the cumulative ranking curve analysis, RT+XELOX had the best outcomes in terms of pCR (79.18%) and OS (83.49%) and RT plus capecitabine, irinotecan, and cetuximab (RT+XELIRI+CET) ranked first with respect to DFS (87.86%). CONCLUSIONS: RT+XELOX is likely to be the best treatment with a comprehensive curative effect and the standard treatment of 5-fluorouracil-based chemoradiotherapy has some advantages, as well. More relevant evidence is needed for clinicians' guidance.

Analysis of pemetrexed-based chemotherapy in the treatment of advanced colorectal cancer.

BACKGROUND: In this study, we evaluated the therapeutic efficacy and toxicity profile of chemotherapy combinations containing pemetrexed for patients with metastatic colorectal cancer. We investigated the optimal chemotherapy treatment regimen to provide a new option for third-line or after treatment of patients with advanced colorectal cancer. METHODS: A total of 88 eligible patients with metastatic colorectal cancer were included in this study from April 2009 to March 2019 at the Department of Oncology, the First Affiliated Hospital of Nanjing Medical University. The baseline information and treatment outcomes of the patients were collected. Statistical analyses of different chemotherapy regimens focusing on objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and toxicity were conducted. The superior treatment regimen was determined, and its clinical outcomes were compared with those of the other treatment combinations to explore the factors that potentially contributed to the curative effect. RESULTS: The 88 patients in this study received 18 treatment regimens. In total, 53 patients had progressive disease (PD), 34 patients had stable disease (SD), 1 patient was assessed as complete response (CR), and no patients had a partial response (PR). The optimal regimen was pemetrexed + S-1 + bevacizumab. The 21 patients treated with this regimen exhibited a higher DCR [61.90% vs. 32.84%, odds ratio (OR) =3.324; 95% confidence interval (CI): 1.201-9.196, P=0.018] than patients treated with the other chemotherapy regimens. Moreover, the median PFS of this regimen was 4.57 (2.62-6.51) months, which was significantly longer [hazard ratio (HR) =0.566; 95% CI: 0.330-0.971, P=0.039] than the 2.57 (2.18-2.95) months of the other regimens. In terms of toxicity, leukopenia (34.1%) and neutropenia (34.1%) had the highest incidence of all-grade adverse events (AEs). Grade 3-4 AEs included neutropenia (15.9%), leukopenia (11.4%), thrombocytopenia (2.3%), and anemia (1.1%). CONCLUSIONS: The combination of pemetrexed + S-1 + bevacizumab was found to be the optimal treatment regimen. This combination was superior to the other treatment regimens in terms of DCR and PFS with controllable toxicity. These results warrant further prospective exploratory clinical trials for pemetrexed-based chemotherapy in metastatic colorectal cancer.

Uric acid preconditioning alleviated doxorubicin induced JNK activation and Cx43 phosphorylation associated cardiotoxicity via activation of AMPK-SHP2 signaling pathway.

BACKGROUND: Doxorubicin is an anthracycline antibiotic, which is effective for treating various malignancies such as leukemias and lymphomas. However, its serious cumulative dose-dependent cardiotoxicity limits its clinical application. Previous studies have shown that doxorubicin-associated cardiotoxicity is closely related to adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK). Uric acid is known to exert a strong antioxidant function and moderate protection on the nerves. However, its cardioprotective properties have not been established. This study aimed to investigate the potential effect of uric acid preconditioning on doxorubicin-induced cardiotoxicity and the involvement of AMPK signaling in this process. METHODS: An acute cardiotoxicity model of doxorubicin was established by intraperitoneal injection of a single dose of doxorubicin (20 mg/kg) in mice. Uric acid (62.5, 125, and 250 mg/kg) was intragastrically administered to mice one day before doxorubicin treatment and then continuously administered every 24 h for 8 consecutive days. The mortality rate and weight of the mice were recorded every day. Electrocardiograms (ECG) and serum biochemicals were detected with an ECG instrument and enzyme-linked immunosorbent assay kit (Elisa) respectively. A real-time cell analyzer (RTCA) was used to investigate the cytotoxicity of doxorubicin in vitro. Cell signaling was assayed by western blotting. RESULTS: Uric acid (125 mg/kg) preconditioning increased the survival rate and body weight of doxorubicin-treated mice. Uric acid also effectively alleviated prolongation of the doxorubicin-induced QT interval, slowed heart rate, and reduced the plasma levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) in plasma in mice. Moreover, uric acid strongly activated AMPK and Src homology 2 domain-containing protein tyrosine phosphatase (SHP2), inhibiting doxorubicin-induced expression phosphorylated-c-Jun N-terminal kinases (JNK) and phosphorylated-connexin 43 (Cx43) in vitro and in vivo and effectively reversing the doxorubicin-induced decreased viability of H9C2 myocardial cells in vitro. CONCLUSIONS: We demonstrated that uric acid preconditioning alleviated doxorubicin-induced cardiotoxicity through the AMPK-SHP2-JNK-Cx43 signaling pathway.

Comprehensive Analysis of lncRNA-miRNA- mRNA Network Ascertains Prognostic Factors in Patients with Colon Cancer.

BACKGROUND: Non-coding RNAs are competing endogenous RNAs in the occurrence and development of tumorigenesis; numerous microRNAs are aberrantly expressed in colon cancer tissues and play significant roles in oncogenesis development and metastasis. However, large clinical and RNA data are lacking to further confirm the exact role of these RNAs in tumors. This study aimed to ascertain differential RNA expression between colon cancer and normal colon tissues. MATERIALS AND METHODS: RNA sequencing and clinical data of patients with colon cancer were procured from The Cancer Genome Atlas database; differentially expressed long non-coding RNA, differentially expressed messenger RNAs, and differentially expressed microRNAs were achieved using the limma package in edgeR to generate competing endogenous RNAs networks. Then, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were conducted with ggplot2 package, the Kaplan-Meier survival method was used to predict survival in patients with colon cancer. RESULTS: In total, 1174 differentially expressed long non-coding RNAs, 2068 differentially expressed messenger RNAs, and 239 differentially expressed microRNAs were generated between 480 colon cancer and 41 normal colon tissue samples. Three competing endogenous RNA networks were established. Gene Ontology analysis indicated that the genes of the up-regulated microRNA network were involved in negative regulation of transcription, DNA-template, and those of down-regulated microRNA network were involved in transforming growth factor ß receptor signaling pathways, response to hypoxia, cell migration, while Kyoto Encyclopedia of Genes and Genomes analyses of these networks turned out to be negative. Three long non-coding RNAs (AP004609.1, ARHGEF26-AS1, and LINC00491), 3 microRNAs (miRNA-141, miRNA-216a, and miRNA-193b) and 3 RNAs (ULBP2, PHLPP2, and TPM2) were detected to be associated with prognosis by the Kaplan-Meier survival analysis. Additionally, univariate and multivariate Cox regression analyses showed that the microRNA-216a of the competing endogenous RNA might be an independent prognostic factor in colon cancer. CONCLUSIONS: This study constructed the non-coding RNA-related competing endogenous RNA networks in colon cancer and sheds lights on underlying biomarkers for colon cancer cohorts.

Role of CXCR3 signaling in response to anti-PD-1 therapy.

BACKGROUND: Tumor mutations and tumor microenvironment are associated with resistance to cancer immunotherapies. However, peripheral T cell in effective anti-programmed death 1 (PD-1) antibody treatment is poorly understood. METHODS: Mass spectrometry and conventional flow cytometry were used to investigate peripheral blood cells isolated from patients. Furthermore, melanoma mouse model was performed to assess the role of CXCR3 signaling in anti-PD-1 antibody treatment. FINDINGS: We revealed a marked increase in the percentage of CXCR3+ T cells in the blood of cancer patients after the first pembrolizumab infusion. This percentage decreased after the second infusion in responsive patients, whereas a sustained high percentage of CXCR3+ T cells was observed in patients with progressive disease. A low percentage of CXCR3+ T cells presented in patients with stable disease or a partial response was confirmed by conventional flow cytometry. Intriguingly, blockade of CXCR3 signaling exacerbated tumor growth in mice. Intratumoral injection with recombinant CXCL9/10 plus intraperitoneal injection of anti-PD1 antibody inhibited the tumor growth in mice. INTERPRETATION: The dynamic changes in CXCR3+ T cells in blood may be a prognostic factor in anti-PD-1 immunotherapy, and promotion of CXCR3-mediated signaling may be beneficial to the anti-PD-1 therapy. FUND: This work was supported by the National Natural Science Foundation of China (Nos. 81722047, 81871944, 81670553, 81874317, 81572389, 81730100) and Jiangsu province key medical talents (Nos. ZDRCA2016026), The "Deng Feng" Distinguished Scholars Program, National Science & Technology Major Project "Key New Drug Creation and Manufacturing Program", China (Number: 2018ZX09201002), and the Fundamental Research Funds for the Central Universities (020814380117).