Plasma thioredoxin reductase: a potential diagnostic biomarker for gastric cancer.

To improve the early detection of gastric cancer (GC), there is a growing need for novel and efficient biomarkers. We aimed to evaluate diagnostic value of thioredoxin reductase 1 (TXNRD1), which was found to be over expressed in various malignancies. We found that TXNRD1 has a higher expression level in GC tissues compared with adjacent normal tissues, and high TXNRD1 expression was significantly associated with poor outcomes of GC patients. Next, a total of 1446 cases were collected, with 896 cases in GC, 322 in benign gastric disease and 228 in healthy controls. We noticed plasma thioredoxin reductase (TrxR) level in GC [8.4 (7.1, 9.7) U/ml] was significantly higher than that in benign disease [6.1 (5.4, 7.2) U/ml] or healthy controls [3.7 (1.7, 5.6) U/ml]. Receiver operating characteristic analysis showed that the optimal cutoff value of TrxR activity for GC diagnosis was set at 5.75 U/ml with an area under the curve of 0.945. Moreover, a combined panel of TrxR and routine tumor markers could further elevate the diagnostic efficacy compared to a single biomarker. Finally, by measuring pre- and post-treatment TrxR activity and routine tumor markers, we found the change trend of them was broadly consistent, and plasma TrxR activity was significantly decreased in patients treated with platinum/fluorouracil-based therapy. Our findings recommend plasma TrxR activity combined with tumor markers as effective diagnostic tools for GC patients. As well, plasma TrxR has the potential to monitor therapeutic efficacy.

SOX2-OT induced by PAI-1 promotes triple-negative breast cancer cells metastasis by sponging miR-942-5p and activating PI3K/Akt signaling.

Triple-negative breast cancer (TNBC) has an aggressive biological behavior and poor outcome. Our published study showed that PAI-1 could induce the migration and metastasis of TNBC cells. However, the underlying mechanism by which PAI-1 regulates TNBC metastasis has not been addressed. Here, we demonstrated that PAI-1 is high expressed in TNBC and promotes TNBC cells tumorigenesis. Using microarray analysis of lncRNA expression profiles, we identified a lncRNA SOX2-OT, which is induced by PAI-1 and could function as an oncogenic lncRNA in TNBC. Mechanistic analysis demonstrated that SOX2-OT acts as a molecular sponge for miR-942-5p to regulate the expression of PIK3CA, ultimately leading to activating PI3K/Akt signaling pathway and promoting TNBC metastasis. Taken together, our findings suggest that SOX2-OT regulates PAI-1-induced TNBC cell metastasis through miR-942-5p/PIK3CA signaling and illustrate the great potential of developing new SOX2-OT-targeting therapy for TNBC patients.

Exosomal Transfer Of Cisplatin-Induced miR-425-3p Confers Cisplatin Resistance In NSCLC Through Activating Autophagy.

INTRODUCTION: Exosomes are important mediators of intercellular communication. Previously, we characterized circulating exosomal miR-425-3p as a non-invasive prognostic marker for predicting clinical response to platinum-based chemotherapy in patients with non-small cell lung cancer (NSCLC). METHODS: Circulating exosomal miR-425-3p was validated by qRT-PCR in paired serum samples from NSCLC patients during the course of platinum-based chemotherapy. Cell coculture was performed to examine the effects of exosomal miR-425-3p on the sensitivity of recipient A549 cells to cisplatin. Using bioinformatics, ChIP and luciferase reporter assays, the transcription factor essential for miR-425-3p expression was identified. Autophagic activity in the recipient cells was determined by Western blot and fluorescence microscopy. RESULTS: Higher levels of exosomal miR-425-3p were found in serum samples from the patients in tolerance versus those at baseline. An upward trend in the expression of circulating exosomal miR-425-3p was revealed during chemotherapy. Furthermore, the expression of exosomal miR-425-3p could be induced by cisplatin in NSCLC cells. Exosomes isolated from either cisplatin-treated or cisplatin-resistant NSCLC cells conferred chemoresistance to sensitive A549 cells in a miR-425-3p-dependent manner. Cisplatin-induced c-Myc was found to directly bind the miR-425-3p promoter and transactivated its expression. Exosomal miR-425-3p facilitated autophagic activation in the recipient cells by targeting AKT1, eventually leading to chemoresistance. DISCUSSION: Our results suggest that apart from a prognostic marker of treatment response, exosomal miR-425-3p might be a potential dynamic biomarker to tailor cisplatin resistance in NSCLC patients during the treatment and represent a promising therapeutic target for therapy-resistant NSCLC.

Prognostic Role of Circulating Exosomal miR-425-3p for the Response of NSCLC to Platinum-Based Chemotherapy.

BACKGROUND: Platinum-based doublets with a third-generation agent are the recommended option for many patients with non-small cell lung cancer (NSCLC) with no contraindications to platinum compounds. Unfortunately, the clinical effectiveness of such chemotherapy is limited by intrinsic or acquired resistance. METHODS: Circulating exosomal miRNAs were isolated and used to perform HiSeq deep-sequencing analyses on serum pool samples from platinum-resistant or platinum-sensitive patients, and six exosomal miRNAs were further validated for their predictive utility by qRT-PCR in 170 serum samples of patients with advanced NSCLC. Gain- and loss-of-function experiments clarified the responsiveness regulating role of the clinically relevant miRNA. IHC analyses were performed to evaluate the association between basal autophagy in lung cancer tissues and responsiveness in 203 patients with NSCLC receiving platinum-based chemotherapy. RESULTS: Six circulating exosomal miRNAs (miR-425-3p, miR-1273h, miR-4755-5p, miR-9-5p, miR-146a-5p, and miR-215-5p) were found to be differentially expressed with the largest fold change in platinum-resistant patients compared with platinum-sensitive patients. High miR-425-3p proved to be a potent predictive biomarker for low responsiveness and poor progression-free survival (PFS). Mechanistically, miR-425-3p upregulated the autophagic levels via targeting AKT1, leading to the decrease in therapeutic response. Concordantly, high levels of basal autophagy in lung cancer tissues correlate with low responsiveness in patients with NSCLC within the early and advanced disease stages. CONCLUSIONS: Our study highlights circulating exosomal miR-425-3p as a potential biomarker for improved predictions of the clinical response to platinum-based chemotherapy in patients with NSCLC. IMPACT: This study provides the first evidence that miR-425-3p in NSCLC patient-derived exosomes can be a marker for predicating the clinical response to platinum-based chemotherapy.

Andrographolide enhances cisplatin-mediated anticancer effects in lung cancer cells through blockade of autophagy.

Lung cancer is the most common cause of cancer-related death worldwide and the platinum-based drugs such as cisplatin have been used as the first line of the treatment. However, the clinical effectiveness of such chemotherapy is limited by intrinsic or acquired resistance. In this study, we found that cisplatin induced autophagy that attenuated the sensitivity of both A549 and Lewis lung cancer (LLC) cells to cisplatin. In contrast, the clinical drug andrographolide (Andro) suppressed autophagy and enhanced cisplatin-mediated apoptosis in these cells. Using two murine lung cancer models, including a subcutaneously inoculated LLC model and an orthotopic LLC implantation model, we investigated the therapeutic efficacy of the combined treatment of cisplatin and Andro. Compared with the sole cisplatin treatment, combining cisplatin with Andro potentially inhibited tumor growth, reduced the incidence of lung metastases, and relieved renal tubular damage. Moreover, the combined treatment prolonged the life span of tumor-bearing mice. TUNEL and immunohistochemistry assays showed the increase in apoptotic cells and the decrease in both conversion of LC3B-I to LC3B-II and Atg5 protein expression in the tumor tissues from mice with the combined treatment. These results suggest that Andro offers an ideal candidate of autophagy inhibitors in clinical application, and combination of cisplatin with Andro could be a promising strategy for the treatment of lung cancer.

Inhibition of autophagy by andrographolide resensitizes cisplatin-resistant non-small cell lung carcinoma cells via activation of the Akt/mTOR pathway.

Resistance to cisplatin is a major obstacle for the success of non-small cell lung cancer therapy. The mechanisms underlying cisplatin resistance are not fully understood. In this study, we found that the increase of basal auotophagy accompanied the development of cisplatin resistance. Meanwhile the blockade of the Akt/mTOR pathway occurred in the process. Inhibition of this pathway was induced by cisplatin treatment in the resistant non-small cell lung carcinoma cells. Andrographolide, a natural diterpenoid, promoted the activation of the Akt/mTOR signaling by downregulating PTEN and suppressed autophagy, which subsequently resensitized the resistant cells to cisplatin-mediated apoptosis. Cisplatin treatment in combination with andrographolide significantly prevented the growth of the resistant cells in vivo. These results highlight the involvement of autophagy in cisplatin-resistance development and suggest that inhibition of autophagy via tuning the Akt/mTOR signaling could be a promising strategy in the therapy for cisplatin-resistant non-small cell lung cancer.