Nuclear factor erythroid 2-related factor 2 promotes radioresistance by regulating glutamate-cysteine ligase modifier subunit and its unique immunoinvasive pattern.

The enzyme glutamate-cysteine ligase modifier subunit (GCLM) serves as the initial rate-limiting factor in glutathione (GSH) synthesis. GSH is the preferred substrate for glutathione peroxidase 4 (GPX4), directly impacting its activity and stability. This study aims to elucidate the expression of GCLM and its correlation with the nuclear factor erythroid 2-related factor 2 (NFE2L2), commonly referred to as NRF2, in esophageal squamous cell carcinoma (ESCC) and further investigate the potential signaling axis of radiotherapy resistance caused by NRF2-mediated regulation of ferroptosis in ESCC. The expression of NRF2, GCLM, and GPX4 in ESCC was analyzed by bioinformatics, and their relationship with ferroptosis was verified through cell function experiments. Their role in radioresistance was then investigated through multiple validation steps. Bioinformatics analysis was employed to determine the immune infiltration pattern of NRF2 in ESCC. Furthermore, the effect of NRF2-mediated massive macrophage M2 infiltration on radiotherapy and ferroptosis was validated through in vivo experiments. In vitro assays demonstrated that overactivated NRF2 promotes radioresistance by directly binding to the promoter region of GCLM. The Tumor Immune Estimation Resource (TIMER) and quanTIseq analyses revealed NRF2 enrichment in M2 macrophages with a positive correlation. Co-culturing KYSE450 cells with M2 macrophages demonstrated that a significant infiltration of macrophages M2 can render ESCC cells resistant to radiotherapy but restore their sensitivity to ferroptosis in the process. Our study elucidates a link between the NRF2-GCLM-GSH-GPX4 signaling axis in ESCC, highlighting its potential as a therapeutic target for antagonistic biomarkers of resistance in the future. Additionally, it provides a novel treatment avenue for ESCC metastasis and radioresistance.

DPP3 expression promotes cell proliferation and migration in vitro and tumour growth in vivo, which is associated with poor prognosis of oesophageal carcinoma.

Dipeptidyl peptidase III (DPP3), a zinc­dependent metallopeptidase, is upregulated in a variety of malignancies. However, little is known about its roles in the pathogenesis of these malignancies. The present study was designed to investigate the roles of DPP3 in the pathogenesis and progression of oesophageal cancer (EC). The expression level of DPP3 in EC tissues and adjacent normal tissues was detected in 93 cases of tissue biopsies collected from patients diagnosed with oesophageal carcinoma by immunohistochemistry. The effect of DPP3 expression on cell proliferation, migration or apoptosis was determined in DPP3­depleted EC cells created by infection with lentivirus containing short hairpin RNA specific to the human DPP3 mRNA sequence, followed by detection at the cellular level using a Celigo cell count assay, flow cytometry, wound­healing assay and Transwell assay as well as chip screening with a Human Apoptosis Antibody Array kit, which enables the quantitative detection of 43 apoptosis­related genes. A xenograft model was applied to detect the tumour growth and invasion of DPP3­depleted cancer cells in nude mice. The results revealed that DPP3 expression was elevated in EC tissues compared with adjacent non­tumour tissues, and high DPP3 expression was significantly associated with poor prognosis. DPP3 depletion resulted in reduced cell proliferation and migration and enhanced cell cycle arrest and apoptosis of EC cells and led to the inhibition of tumour growth and invasion in a xenograft model. In addition, DPP3 depletion was associated with the upregulation of the proapoptotic proteins SMAC and p53 and the downregulation of the antiapoptotic proteins clAP­2, IGFBP­2 and TRAILR­4. Finally, DPP3 may promote cell proliferation, migration and survival of EC cells in vitro and tumour growth and invasion of oesophageal carcinoma in vivo, and thus may serve as a molecular target for tumour therapy.

Downregulation of microRNA-519 enhances development of lung cancer by mediating the E2F2/PI3K/AKT axis.

MicroRNA-519 (miR-519) acts as an inhibitor in different kinds of tumors. The current study was set to probe the function of miR-519 in lung cancer and to explore the potential molecular mechanism. The expression difference of miRNAs between lung cancer and paracancerous tissues was analyzed by microarray. miR-519 expression was significantly diminished in lung cancer tissues and cells. After that, EdU staining, CCK-8 assay, Transwell assay, Hoechst 33258 staining and PI/Annexin-V staining revealed that overexpression of miR-519 in lung cancer cells inhibited their viability and promoted apoptosis. TragetScan and miRSearch were employed to predict the target mRNAs of miR-519, which were verified by a luciferase activity assay. miR-519 bound to the 3'untranslated region of E2F transcription factor 2 (E2F2) mRNA. Finally, the extent of PI3K/AKT signaling pathway phosphorylation was examined, which illustrated that upregulation of miR-519 repressed the phosphorylation of the PI3K/AKT pathway in SPC-A-1 and 95C cells. miR-519 reduces PI3K/AKT pathway activities by suppressing the transcription activity of E2F2, thereby potentially inhibiting the occurrence of lung cancer.

Functional analysis of serum microRNAs miR-21 and miR-106a in renal cell carcinoma.

OBJECTIVE: microRNAs (miRNAs) plays an important role in tumor development and progression and act as oncogenes or tumor suppressor genes in the carcinogenesis process. miRNA is stable in serum, and recent studies have demonstrated the feasibility of using circulating miRNA as biomarkers in cancer patients. However, currently, no serum biomarkers for the early diagnosis and prognosis of renal cell carcinoma (RCC) have been reported. Therefore, a new molecular marker for early diagnosis and evaluation of recurrence after surgery is required. Our purpose was to identify miRNA signatures that could distinguish the serum of RCC patients from matched healthy controls and validate identified miRNAs as potential biomarkers for RCC. METHOD: Serum samples from 30 RCC patients were collected before and 1 month after surgery. 30 cancer-free blood donor volunteers with no history of any cancer were recruited from the same institute. miR-21 and miR-106a expression levels were determined by real-time PCR. RESULT: The serum miR-21 level was significantly higher in RCC patients (median, 8.34) than in healthy control individuals (median, 0.70; p= 0.001). A month after surgery, serum miR-21 levels (median, 0.69) were significantly reduced (p= 0.032). The serum miR-106a level was higher in RCC patients (median, 8.99) compared with controls (median, 0.96; p= 0.000), while miR-106a levels (median, 1.01) were reduced a month after surgery (p= 0.028). The expression level of miR-21 and miR-106 a in RCC patients increased significantly, while miR-21 and miR-106a decreased after surgery. This outcome suggests that serum miR-21 and miR-106a expression level was closely related with kidney cancer tissue. CONCLUSION: We conclude that serum miR-21 and miR106a are expected to be molecular markers for RCC.

Differential expression and clinical significance of serum protein among patients with clear-cell renal cell carcinoma.

BACKGROUND AND OBJECTIVE: Looking for tumor markers by using protein chip technology is one of the hot topics, but many studies are still limited on short term detection of differential expressed proteins before and after surgery among patients with RCC. This study analyzed differential expressed serum protein and its clinical significance with clear-cell renal cell carcinoma to further measurement of the rule of variable expressing. METHODS: Eighty-nine patients with clear-cell renal cell carcinoma who underwent surgery from November 2013 to 2014 and postoperatively confirmed by pathology were entered in RCC group, 100 healthy volunteers and patients without RCC who underwent medical examination in the same period were entered in control group. The serum protein were analyzed in both group before surgery and every regular follow-up period in 1 year after surgery with RCC group. The surface-enhanced laser desorption ionization time of flight mass spectrometry (SELDI-TOF-MS) and weak cation exchange protein chip (CM10) technology systems were used for identifying differential expressed serum protein in RCC group and controls. The linear support vector machine (SVM) was applied to establish the diagnostic model of protein fingerprints and the leave-one-out cross validation was used for determining model discriminating effect. The differential expressed proteins were analyzed by ZUCI-PDAS protein spectral data analysis system. RESULTS: Five kinds of proteins were identified as potential biomarker, ultimately. The M/Z of these proteins was 15953, 7987, 9304, 8948, 5911, respectively. There were significant difference on expression level of these proteins with two groups preoperatively (P< 0.05). Comparison of all postoperative expression levels to preoperative one and each differential level mutually between a year in postoperative period also revealed statistical significance (P< 0.05). With taking identified proteins as biomarker, the sensitivity and specificity in predicting clear-cell renal cell carcinoma was 88.8% (79/89) and 91.0% (91/100), respectively. CONCLUSION: The corresponding specific protein was Bcl-2 family apoptosis regulatory proteins, WAP four-disulfide core protein, Krueppel-like factor 8, monocyte chemotactic protein-1, serum amyloid ß -protein-4, respectively, and will may serve as tumor markers of kidney cancer. These proteins manifests high predictive value for clear-cell renal cell carcinoma, and may contribute to therapeutic evaluation, prognosis and targeted therapy for clear-cell renal cell carcinoma.