Mycobacterium smegmatis enhances shikonin-induced immunogenic cell death-an efficient in situ tumor vaccine strategy.

Tumor vaccines are a promising avenue in cancer immunotherapy. Despite the progress in targeting specific immune epitopes, tumor cells lacking them can evade treatment. Here, we aimed to construct an efficient in situ tumor vaccine Vac-SM, utilizing shikonin (SKN) to induce immunogenic cell death (ICD) and Mycobacterium smegmatis ( M. smegmatis) as an immune adjuvant to enhance in situ tumor vaccine efficacy. SKN demonstrated a dose-dependent and time-dependent cytotoxic effect on the tumor cell line as seen using the CCK-8 assay and induced ICD in tumor cells by detecting the expression of relevant indicators respectively. Compared to that in the control groups, in situ Vac-SM injection in mouse subcutaneous metastatic tumors significantly inhibited tumor growth and distant tumor growth and improved survival rates. M. smegmatis effectively induced bone marrow-derived dendritic cells (DC) maturation and activation and in vivo tumor-draining lymph nodes showed increased maturation of DC and a higher proportion of effector memory T-cell subsets with Vac-SM treatment, based on flow cytometry analysis results.Collectively, Vac-SM vaccine effectively induces ICD, improves antigen presentation by DC, activates a specific systemic antitumor T-cell immune response, exhibits favorable safety profile, and holds promise for clinical translation for local tumor immunotherapy.

miR­142­5p inhibits pancreatic cancer cell migration and invasion by targeting PIK3CA.

Pancreatic cancer is a fatal disease with a high mortality rate and poor prognosis worldwide. The aberrant expression of microRNAs (miRs) is associated with cancer development and progression. The present study aimed to evaluate the functional role of miR­142­5p in migration and invasion, and investigated its underlying molecular mechanism in pancreatic cancer cells. First, it was identified that miR­142­5p expression was downregulated in pancreatic cancer tissues and cell lines by reverse transcription­quantitative polymerase chain reaction. Furthermore, phosphoinositide­3­kinase catalytic subunit α (PIK3CA) was identified as a target of miR­142­5p. The expression of PIK3CA was upregulated in tumor tissues and its expression was negatively regulated by miR­142­5p expression. Notably, overexpression of miR­142­5p inhibited the proliferation, migration and invasion of PanC1 cells, while PIK3CA reversed this inhibition. In addition, miR­142­5p suppressed the expression of focal adhesion kinase (FAK) and matrix metalloproteinase (MMP)9, as well as phosphorylated protein kinase B (AKT) protein level, while PIK3CA reversed the suppression induced by miR­142­5p. In conclusion, miR­142­5p functions as a tumor suppressor, which inhibits the migration and invasion of pancreatic cancer by suppressing the expression of FAK and MMP9, as well as the phosphatidylinositol 3­kinase/AKT signaling pathway by targeting PIK3CA. These findings suggest that miR­142­5p may be a novel therapeutic target for the treatment of pancreatic cancer.

PRAF2 overexpression predicts poor prognosis and promotes tumorigenesis in esophageal squamous cell carcinoma.

BACKGROUND: Prenylated Rab acceptor 1 domain family, member 2 (PRAF2) is involved in the occurrence and progression of several malignant tumors. However, its potential role in esophageal squamous cell carcinoma (ESCC) is still unknown. METHODS: PRAF2 mRNA expression was determined in 77 frozen ESCC samples by quantitative reverse transcription-polymerase chain reaction (qPCR) and its association with clinical features and overall survival were evaluated. The roles of PRAF2 in ESCC cells were investigated by proliferation, cell cycle, invasion and apoptosis assays in vitro. RESULTS: The PRAF2 mRNA expression was significantly increased in ESCC tissues compared with matched surrounding non-tumor tissues. Survival analysis showed that high PRAF2 mRNA expression was associated with worse overall survival in ESCC patients. Multivariate analysis revealed that PRAF2 (hazard ratio 2.05, 95% CI 1.10-3.85, P = 0.025) emerged as the independent predictor for poor overall survival in ESCC. The in vitro experiments revealed that knockdown of PRAF2 expression blocked cell proliferation, cell cycle progression and cell invasion and induced cell apoptosis in ESCC cells. CONCLUSION: Taken together, our data demonstrate that PRAF2 could be used as a potential prognostic biomarker and represent a potential therapeutic target for ESCC.

Intronic polymorphisms in genes LRFN2 (rs2494938) and DNAH11 (rs2285947) are prognostic indicators of esophageal squamous cell carcinoma.

BACKGROUND: Genome wide association study (GWAS) has become the major means to screen for the genetic variants associated with risk and prognosis of different diseases. A recent GWAS has discovered three novel intronic single nucleotide polymorphisms in genes LRFN2 (rs2494938), DNAH11 (rs2285947) and PLCXD2 (rs2399395) that are associated with altered risk of esophageal squamous cell carcinoma (ESCC) among Han Chinese populations. However, the prognostic significance of these variations in ESCC remains unclear. METHODS: To investigate the association of three novel single nucleotide polymorphisms (rs2494938, rs2285947, rs2399395) with the prognosis of ESCC patients, we recruited 287 ESCC patients treated with surgical resection and evaluated the potential significance of the three polymorphisms through Kaplan-Meier survival analysis, log-rank test, and Cox proportional hazards regression models. RESULTS: The ESCC patients carrying genotype AA at rs2494938 had worse survival and genotype GG at 2285947 had better prognosis (Log-rank P = 0.003 and Log-rank P = 0.037, respectively). In addition, rs2494938 at 6p21.1 was independently associated with overall survival of ESCC patients in recessive model [AA vs. GG/GA, HR = 3.12, 95% CI = 1.43-6.83, P = 0.004], rs2285947 at 7p15.3 was independently associated with overall survival of ESCC patients in both dominant model [AA/GA vs. GG, HR = 1.59, 95% CI = 1.02-2.49, P = 0.042] and additive model [AA vs. GA vs. GG, HR = 1.45, 95% CI = 1.05-2.01, P = 0.025]. CONCLUSIONS: This study demonstrated that the polymorphisms rs2494938 at 6p21.1 and rs2285947 at 7p15.3 may serve as independent prognostic biomarkers for ESCC, implying the potential biological role of their related genes (LRFN2 and DNAH11) in the process of ESCC development.

miR-142-5p regulates pancreatic cancer cell proliferation and apoptosis by regulation of RAP1A.

Pancreatic cancer, one of the fatal and aggressive malignancies, leads the sixth cancer-associated death in China. microRNAs are believed to exert function in the diagnosis and treatment of pancreatic cancer. In the present study, we firstly found that miR-142-5p was downregulated in pancreatic cancer tumor tissues while Ras-related protein Rap-1 A (RAP1A) was upregulated compared with para-carcinoma non-tumor tissues. Then, we found that RAP1A could be a putative target gene of miR-142-5p by bioinformatics tool TargetScan. Furthermore, we conducted luciferase reporter assay, RT-qPCR, western blot and correlation analysis to demonstrate that miR-142-5p could negatively regulate RAP1A expression by binding to its 3'UTR. In addition, cell-counting kit 8 (CCK-8) and flow cytometry assays certified that miR-142-5p overexpression may inhibit pancreatic cancer cell proliferation but promote cell apoptosis; while the variation could be reversed by co-transfected with pcDNA3.1-RAP1A. Finally, miR-142-5p overexpression downregulated p-ERK1/2, phosphate p38 mitogen-activated protein kinases (p-p38); however, the variation induced by miR-142-5p mimic could be reversed by co-transfected with pcDNA3.1-RAP1A. In conclusion, our findings indicate that targeting miR-142-5p may provide a novel strategy for the treatment of pancreatic cancer.

Combination of histoculture drug response assay and qPCR as an effective method to screen biomarkers for personalized chemotherapy in esophageal cancer.

Personalized chemotherapy with the use of biomarkers helps to maximize clinical efficiency. Therefore, the present study aimed to identify a potential method for identifying biomarkers in esophageal cancer. A total of 49 freshly resected tumor tissues and 72 paraffin-embedded specimens from patients with esophageal cancer were obtained. mRNA expression levels of ERCC1, BRCA1, TUBB3, FBW7, RRM1, MDM2, TS and TOP1 were measured quantitative reverse transcription polymerase chain reaction (RT-qPCR). In vitro chemosensitivity to cisplatin, docetaxel, gemcitabine, etoposide, fluorouracil and irinotecan were tested using histoculture drug response assay (HDRA). BRCA1 mRNA levels were positively correlated with resistance to cisplatin (P=0.027) and sensitivity to docetaxel (P=0.002). TS mRNA levels were inversely correlated with fluorouracil sensitivity (P=0.044), and TOP1 mRNA expression was positively correlated with irinotecan sensitivity (P=0.008). In addition, high BRCA1 mRNA levels correlated with decreased median overall survival (mOS; P<0.001) and response rate (RR; P=0.002) in cisplatin-fluorouracil chemotherapy group and also correlated with increased mOS (P<0.001) and RR (P=0.023) in docetaxel-fluorouracil chemotherapy group. Overall, these results suggested that HDRA combined with RT-qPCR may serve as an effective method for screening biomarkers in personalized chemotherapy for esophageal cancer.

Delivery of a chemotherapeutic drug using novel hollow carbon spheres for esophageal cancer treatment.

Low toxicity and high efficacy are the key factors influencing the real-world clinical applications of nanomaterial-assisted drug delivery. In this study, novel hollow carbon spheres (HCSs) with narrow size distribution were developed. In addition to demonstrating their ease of synthesis for large-scale production, we also demonstrated in vitro that the HCSs possessed high drug-loading capacity, lower cell toxicity, and optimal drug release profile at low pH, similar to the pH in the tumor microenvironment. The HCSs also displayed excellent immunocompatibility and could rapidly distribute themselves in the cytoplasm to escape lysosomal clearance. More importantly, the HCSs could efficiently deliver doxorubicin (a representative chemotherapeutic drug) to tumor sites, which resulted in significant inhibition of tumor growth in an esophageal xenograft cancer model. This also prolonged the circulation time and altered the biodistribution of the drug. In conclusion, this study revealed a novel drug delivery system for targeted tumor therapy.

Homoharringtonine suppresses imatinib resistance via the Bcl-6/p53 pathway in chronic myeloid leukemia cell lines.

BACKGROUND: The anti-leukemic mechanism of homoharringtonine (HHT) differs from that of IM, and HHT is one of the most useful agents for use in patients with IM resistance or intolerance. The Bcl-6/p53 pathway has been shown to regulate the sensitivity of tumor cells to antitumor drugs. We tested whether HHT blocked the Bcl-6/p53 pathway in order to promote the apoptosis of IM-resistant cells in vitro and in vivo. RESULTS: Ph+ acute lymphoblastic leukemia (ALL) cells and IM-resistant chronic myeloid leukemia (CML) cells showed high expression of Bcl-6 protein. Bcl-6 mediated the upregulation of p53, and and Bcl-6 induced growth inhibition of IM-resistant cells as well as its apoptosis by targeting p53. In addition, Bcl-6 was downregulated moderately after HHT treatment in different cells. The Bcl-6 expression was significantly increased in patients with CML when compared with healthy subjects. Furthermore, the expression of Bcl-6 was higher in patients with CML-blastic phase (CML-BP) than in those with CML-chronic phase (CML-CP). METHODS: The inhibitory effect of drugs on cell growth was detected by Cell Counting Kit-8 (CCK-8), The apoptosis rate and the cell cycle were investigated by flow cytometry. The expression of Bcl-6, p53, Bcl-2, caspase9, and caspase3 proteins was assayed by western blot, Real- Time PCR (qPCR) detect Bcl-6 and p53 mRNA. CONCLUSIONS: HHT can suppress the growth and induce apoptosis of IM-resistant cells, the mechanism of which is associated with blocking of the Bcl-6/p53 pathway. Our results could offer a theoretical explanation for HHT use in patients with IM resistance or intolerance.

Effects of JWA, XRCC1 and BRCA1 mRNA expression on molecular staging for personalized therapy in patients with advanced esophageal squamous cell carcinoma.

BACKGROUND: DNA damage repair genes JWA, XRCC1 and BRCA1 were associated with clinical outcomes and could convert the response to the cisplatin-based therapy in some carcinomas. The synergistic effects of JWA, XRCC1 and BRCA1 mRNA expression on personalized therapy remain unknown in advanced esophageal squamous cell carcinoma (ESCC). METHODS: We employed quantitative real-time polymerase chain reaction (qPCR) to determine the expression of JWA, XRCC1 and BRCA1 mRNA in paraffin-embedded specimen from 172 patients with advanced ESCC who underwent the first-line cisplatin-or docetaxel-based treatments. RESULTS: High JWA or XRCC1mRNA expression was correlated with longer median overall survival (mOS) in all the patients (both P<0.001) or in subgroups with different regimens (all P<0.05), but not correlated with response rate (RR, all P>0.05). Multivariate analysis revealed that high JWA (HR 0.22; 95% CI 0.13-0.37; P<0.001) or XRCC1 (HR 0.36; 95% CI 0.21-0.63; P<0.001) mRNA expression emerged as the independent prognostic factors for ESCC patients in this cohort. But no significant difference in prognostic efficacy was found between JWA plus XRCC1 and JWA alone through ROC analysis. Further subgroup analysis showed cisplatin-based treatments could improve mOS of patients with low JWA expression (P<0.05), especially in those with low BRCA1 expression simultaneously (P<0.001); while in patients with high JWA expression, high BRCA1 mRNA expression was correlated with increased mOS in docetaxel-based treatments (P=0.044). CONCLUSION: JWA, XRCC1and BRCA1 mRNA expression could be used as predictive markers in molecular staging for personalized therapy in patients with advanced ESCC who received first-line cisplatin- or docetaxel-based treatments.