YY1 modulates the radiosensitivity of esophageal squamous cell carcinoma through KIF3B-mediated Hippo signaling pathway.

Radiotherapy is an important strategy in the comprehensive treatment of esophageal squamous cell carcinoma (ESCC). However, effectiveness of radiotherapy is still restricted by radioresistance. Herein, we aimed to understand the mechanisms underlying ESCC radioresistance, for which we looked into the potential role of YY1. YY1 was upregulated in radioresistant tissues and correlated with poor prognosis of patients with ESCC. YY1 depletion enhanced the radiosensitivity of ESCC in vitro and in vivo. Multi-group sequencing showed that downregulation of YY1 inhibited the transcriptional activity of Kinesin Family Member 3B (KIF3B), which further activated the Hippo signaling pathway by interacting with Integrin-beta1 (ITGB1). Once the Hippo pathway was activated, its main effector, Yes-associated protein 1 (YAP1), was phosphorylated in the cytoplasm and its expression reduced in the nucleus, thus enhancing the radiosensitivity by regulating its targeted genes. Our study provides new insights into the mechanisms underlying ESCC radioresistance and highlights the potential role of YY1 as a therapeutic target for ESCC.

Aberrant miR-1246 expression promotes radioresistance in non-small cell lung cancer: a potential prognostic biomarker and radiotherapy sensitization target.

Radiosensitivity varies among patients with non-small cell lung cancer (NSCLC). In this work, we aimed to investigate microRNAs associated with this heterogeneity among individuals. We selected miR-1246 from the microRNAs that were revealed by microarray experiments to be differentially expressed between radioresistant and parental cell lines. Both intracellular and extracellular miR-1246 was found to be upregulated after irradiation in a time-dependent pattern, resulting in increased radioresistance of NSCLC cells. We found that mTOR was a direct target gene of miR-1246, which mediated miR-1246-induced autophagy activation. Yin Yang-1 (YY1) was demonstrated to be a new transcription factor that regulates miR-1246 and CDR1as was found to be a circular RNA that sequesters miR-1246, which was confirmed in NSCLC cells and clinical samples. Finally, combining these data with the results from The Cancer Genome Atlas (TCGA), we verified that miR-1246 could be used as a biomarker to predict NSCLC patients' radiosensitivity and prognosis. Overall, our study fully investigated the effect of miR-1246 on radiosensitivity and comprehensively investigated the potential of miR-1246 as a prognostic biomarker and radiotherapy sensitization target.

Methotrexate-based amphiphilic prodrug nanoaggregates for co-administration of multiple therapeutics and synergistic cancer therapy.

The goal of nanomedicine is to seek strategies that are more efficient to address various limitations and challenges faced by conventional medicines, including lack of target specificity, poor bioavailability, premature degradability, and undesired side effects. Self-assembling drug amphiphiles represent a prospective nanomedicine for cancer therapy owing to their favorable route of administration and therapeutic efficiency compared with pristine drug counterparts. In this work, we report a class of self-deliverable prodrug amphiphiles consisting of the hydrophilic drug methotrexate (MTX) and the hydrophobic anticancer drugs camptothecin (CPT) and doxorubicin (DOX) for targeted and combinational chemotherapy. The disulfide bond and hydrazone bond, which are subject to stimuli-triggered bond cleavage, were introduced to link these therapeutic agents and form two prodrug amphiphiles, named as MTX-CPT and MTX-DOX, respectively, which could self-assemble into stable prodrug nanoaggregates (NAs) in aqueous media. MTX molecules in the prodrug NAs facilitated NA uptake into tumor cells with high expression of folic acid receptors (FRs). This systemic study provided clear evidence of the synergistic therapeutic effect by co-administrating dual prodrug NAs on various tumor cells in vitro and a xenograft tumor model in vivo. The obtained prodrug amphiphiles provide an efficient strategy for the design of multifunctional drug delivery systems and elaborate therapeutic nanoplatforms for cancer chemotherapy. STATEMENT OF SIGNIFICANCE: This work presents two kinds of prodrug amphiphiles that are carrier free and integrate targeted drug delivery, stimuli-triggered drug release, synergistic therapy, and theranostic function into a single system. Reduction/acid active prodrug amphiphiles can self-assemble into micellar nanoaggregates (NAs) at a very low critical aggregation concentration. These NAs exhibit superior stability in physiological environment and disassemble in the presence of tumor cells expressing folic acid receptors or the high glutathione or in low pH tumoral endosomal environment. The induced disassembly of prodrug NAs can "switch on" the inherent fluorescence of the internalized camptothecin or doxorubicin for the detection of tumor cells. Compared to a single type of prodrug NA, co-administration of dual prodrug combination can produce an evident synergistic therapeutic effect against various tumor cells in vitro and inhibit xenograft tumor growth in vivo. The methotrexate-based prodrug amphiphiles may provide a potential strategy for developing multifunctional nanoplatforms and delivery of multiple therapeutics in chemotherapy.

Meta-analysis of the association between selenium and gastric cancer risk.

To clarify the effects of selenium level on the risk of gastric cancer (GC) and GC mortality, a meta-analysis was performed. Related studies were identified from PubMed, EMBASE, Springer Link, Ovid, Chinese Wanfang Data Knowledge Service Platform, Chinese National Knowledge Infrastructure (CNKI), and Chinese Biology Medicine (CBM). Pooled ORs and 95% CIs were used to assess the strengthof the associations. A total of 8 studies including 17834 subjects were involved in this meta-analysis. High selenium level was associated with GC risk in case-control study (OR = 0.62, 95% CI 0.44-0.89, P = 0.009; I2 = 52%) and cohort study (OR = 0.87, 95% CI 0.78-0.97, P = 0.01; I2 = 25%). In addition, high selenium level was associated with GC mortality risk (OR = 0.90, 95% CI 0.84-0.97, P = 0.006, I2 = 49%). In summary, this meta-analysis suggested that selenium might inversely associated with GC risk and GC mortality.

[Protective effects and its mechanisms of total alkaloids from rhizoma Coptis chinensis on Helicobacter pylori LPS induced gastric lesion in rats].

OBJECTIVE: To study the effects and its possible mechanisms of total alkaloids (TA) from rhizoma Coptis chinensis on H. pylori LPS induced gastric lesion in rats. METHOD: H. pylori lipopolysaccharide was applied to rat intragastrically for 4 days to induce a pattern of mucosal responses resembling that of acute gastritis. After treatment with 50, 100, 200 mg x kg(-1) TA, we identified the changes on gastric histopathology, the effects on the activities of cNOS and NOS-2, the contents of TNF-alpha and the gastric mucus epithelial cell apoptosis. RESULT: H. pylori LPS could significantly induce the epithelial cell apoptosis of gastric mucus, increase the expression of NOS-2 and decline the expression of cNOS, and enhance the content of TNF-alpha in serum. Treatment with 50, 100, 200 mg x kg(-1) TA led to reduction in the extent of mucosal inflammatory changes elicited by H. pylori LPS and decrease in epithelial cell apoptosis. Furthermore, this effect of TA was associated with decrease in content of TNF-alpha in serum, decline in NOS-2, and increase in cNOS. CONCLUSION: The findings suggest that TA is a potent protective agent against H. pylori LPS induced gastric mucosal inflammation. The concerned mechanisms may be related to its inhibition on epithelial cell apoptosis, and the suppression of the inflammatory responses by upregulating cNOS and interfering with the events propagated by NOS-2, and reducing the content of TNF-alpha.

[Thermal dosimetric study on hyperthermia combined with radiotherapy for deep seated pelvic malignancies].

OBJECTIVE: To ascertain a clinically meaningful thermal dose unit-temperature equivalent minute (TEM) 42.5 degrees C and the relationship between TEM 42.5 degrees C and tumor response rate. METHODS: From August 1998 to December 2002, 49 patients with recurrent or metastatic malignancies in the pelvis were treated with hyperthermia combined with conventional radiotherapy. Direct thermometry with high resistance lead needle was used whenever possible to measure the temperature by inserting Teflon catheter into the tumor. TEM 42.5 degrees C was used as the thermal dose unit and the relationship between TEM 42.5 degrees C and tumor response rate was monitored. RESULTS: There was a positive correlation between response rate TEM 42.5 degrees C and the radiation dose. The tumor volume and number of heat treatment showed no influence on response. CONCLUSION: Both univariate analysis and multivariate logistic regression analysis indicate that there is a positive correlation between the response rate, TEM 42.5 degrees C and the radiation dose. TEM 42.5 degrees C may act as a useful thermal dose unit in the combination of hyperthermia and radiotherapy. To lower the incidence of complications in thermometry, direct thermometry with high resistance lead needle can be used to measure the temperature by inserting Teflon catheter into the deep-seated malignancies.