TMB Signature-Related RCAN2 Promotes Apoptosis by Upregulating EHF/DR5 Pathway in Hepatocellular Carcinoma.

BACKGROUND: The tumour mutation burden (TMB) is a valuable indicator of the accumulation of somatic mutations, and is thought to be associated with the biological behaviour and prognosis of tumours. However, the related genetic mechanism for these association is still unclear. The aim of the present study was to identify the key gene(s) associated with TMB in hepatocellular carcinoma (HCC) and to investigate its biological functions, downstream transcription factors, and mechanism of action. METHODS: Patients in The Cancer Genome Atlas-Liver Hepatocellular Carcinoma (TCGA-LIHC) database were classified according to TMB signature-related genes. Key genes related to the TMB signature and tumour prognosis were identified. Immunohistochemistry and Quantitative Real-Time Polymerase Chain Reaction (qPCR) were then used to assess gene expression in clinical HCC tissues and HCC cells. Cells with altered gene expression were evaluated for the effect on cell proliferation and apoptosis, both in vitro and in vivo. Three independent databases and cell sequencing data were used to identify the mechanisms involved and the downstream transcription factors. The mechanism was also studied by altering the expression of downstream transcription factors in vitro. RESULT: The integrated cluster (IC) 2 group, characterized by 99 TMB signature-related genes, showed a significant different TMB score compared to the IC1 group (p < 0.001), as well as more favourable tumour prognosis (p = 0.031). We identified five key prognostic genes that were differentially expressed between IC2 and IC1 and were associated with overall survival. The expression of one of these key prognostic genes, RCAN2, was negatively correlated with TMB in 18 out of 33 tumour types examined. A high level of RCAN2 was correlated with better overall survival in HCC (p = 0.0009). Overexpression of RCAN2 enhanced apoptosis in vitro and in vivo, whereas knockdown of RCAN2 attenuated apoptosis. The mechanism by which RCAN2 promotes apoptosis may involve upregulation of the expression of ETS homologous factor (EHF) and of death receptor 5 (DR5). CONCLUSIONS: Downregulation of RCAN2 expression was found to correlate with elevated TMB in multiple cancer types. RCAN2 was also found to be a biomarker of HCC prognosis, and to promote the apoptosis of HCC cells through the EHF/DR5 pathway. These findings provide a new perspective on systemic treatment for advanced HCC with a high TMB.

A sample-to-answer, portable platform for rapid detection of pathogens with a smartphone interface.

Emerging and re-emerging infectious diseases pose global threats to human health. Although several conventional diagnostic methods have been widely adopted in the clinic, the long turn-around times of "gold standard" culture-based techniques, as well as the limited sensitivity of lateral-flow strip assays, thwart medical progress. In this study, a smartphone-controlled, automated, and portable system was developed for rapid molecular diagnosis of pathogens (including viruses and bacteria) via the use of a colorimetric loop-mediated isothermal amplification (LAMP) approach on a passive, self-driven microfluidic device. The system was capable of 1) purifying viral or bacterial samples with specific affinity reagents that had been pre-conjugated to magnetic beads, 2) lysing pathogens at low temperatures, 3) executing isothermal nucleic acid amplification, and 4) quantifying the results of colorimetric assays for detection of pathogens with an integrated color sensor. The entire, 40 min analytical process was automatically performed with a novel punching-press mechanism that could be controlled and monitored by a smartphone. As a proof of concept, the influenza A (H1N1) virus and methicillin-resistant Staphylococcus aureus bacteria were used to characterize and optimize the device, and the limits of detection were experimentally found to be 3.2 × 10-3 hemagglutinating units (HAU) per reaction and 30 colony-forming units (CFU) per reaction, respectively; both such values represent high enough sensitivity for clinical adoption. Moreover, the colorimetric assay could be both qualitative and quantitative for detection of pathogens. This is the first instance of an easy-to-use, automated, and portable system for accurate and sensitive molecular diagnosis of either viruses or bacteria, and it is envisioned that this smartphone-controlled apparatus may serve as a platform for clinical, point-of-care pathogen detection, particularly in resource-limited settings.

MiR-384 regulated IRS1 expression and suppressed cell proliferation of human hepatocellular carcinoma.

Acquired evidence indicated that microRNAs (miRNAs) played essential roles in cancer development, including hepatocellular carcinoma (HCC). Functions and mechanisms of miRNAs involved in HCC remain largely unknown. Here, we found that miR-384 was significantly downregulated in HCC cells and tissues by RT-PCR. Gain and loss of function studies revealed that miR-384 significantly suppressed HCC cell proliferation. Insulin receptor substrate 1(IRS1) was identified as a direct and functional target of miR-384. Moreover, miR-384 decreased IRS1 expression, subsequently downregulating cyclin D1 and upregulating p21 and p-Rb expression. In addition, promotion of cell proliferation caused by miR-384-in was counteracted by silencing IRS1 expression with siRNAs. Taken together, our data provided convincing evidence that miR-384 exerted suppressive effect on HCC cell proliferation through the direct inhibition of IRS1 expression, suggesting miR-384 may serve as a potential therapeutic target for HCC.

Clinical experience in diagnosis and treatment of malignant gastrointestinal stromal tumors.

This study investigated the clinical pathologic character of malignant gastrointestinal stromal tumors (MGIST), their treatment with surgery, and evaluated the efficacy of imatinib postoperation. A total of 68 MGIST patients were enrolled. Of these, 27 patients underwent imatinib auxiliary therapy (treatment group) and 41 underwent imatinib therapy (control group). The therapeutic effects on the two groups were compared using χ(2) test analysis after follow-up of two years. The expressions of CD117, CD34, S100, Vimentin, and alpha smooth-muscle actin (SMA) were detected by immunohistochemistry methods. Of the 68 cases, 28 showed potential MGIST, whereas 40 had MGIST. Haemorrhagia or necrosis, abundant cell, manifest heteromorphism, and caryocinesia were observed in varying degrees. The positive rates of CD117, CD34, Vimentin, S100, and SMA were 89.7% (61/62), 88.2% (60/62), 73.5% (50/62), 41.1% (28/62) and 25.0% (17/62), respectively. The recurrence rate in the treatment group was significantly lower than that in the control group (p < 0.01). We concluded that CD117 and CD34 may be the most valuable markers in the diagnosis of MGIST, and the diagnosis of MGIST depends on the pathology. Surgery is a far better approach in the treatment of such patients, and imatinib is the more efficient target drug in preventing recurrence and metastasis.

[Interference of osteopontin expression inhibits the invasion and metastasis of human hepatocellular carcinoma cell lines].

OBJECTIVE: To investigate the effect of osteopontin (OPN) on the invasion and metastasis of human hapatocellular carcinoma (HCC). METHODS: HCC cell lines (HCC-LM3) were transfected with the chemically synthesized small interfering RNA (siRNA). Real-time PCR and Western blot were used to quantify the mRNA and OPN protein levels. The malignant phenotypes including cellular growth, colony formation and invasion capability of the HCC cells were analyzed. RESULTS: The OPN mRNA and proteins levels were decreased by 75% and 80% in OPN siRNA treated cells. Colony formation and migratory capability were reduced in OPN siRNA treated cells (P < 0.05). CONCLUSION: The specific siRNA is able to reduce the OPN expression at both the mRNA and protein levels and significantly inhibits the invasiveness of HCC cells.

[Adeno-associated virus mediated tumor necrosis factor related apoptosis inducing ligand gene transfected into hepatocellular carcinoma cells by ultrasound microbubble intensifier: an experimental study].

OBJECTIVE: To evaluate the impact of the recombined adeno-associated virus encoding soluble tumor necrosis factor related apoptosis inducing ligand gene (rAAV-sTRAIL) on proliferation and apoptosis of human hepatocellular carcinoma (HCC) cells, and to investigate the feasibility and efficiency of transfection of rAAV-sTRAIL into human HCC cells by ultrasound microbubble intensifier. METHODS: Human HCC cells of the line HepG2 were transfected with rAAV-sTRAIL or rAAV-sTRAIL combined with microbubble echocontrast agent and appropriate dose of ultrasound irradiation. RT-PCR and Western blotting were used to detect the mRNA and protein expression of sTRAIL gene. MTT method was used to detect the proliferation inhibition rate, and the apoptosis rate of the HepG2 cells was evaluated by flow cytometry. RESULTS: The expression levels of sTRAIL mRNA and protein were higher in the rAAV-TRAIL combined with ultrasound microbubble group than in the rAAV-sTRAIL group (both P < 0.05). The proliferation inhibition rate of the rAAV-TRAIL combined with ultrasound microbubble group was significantly higher than that of the rAAV-sTRAIL group (P < 0.05). The apoptotic effect of the rAAV-TRAIL combined with ultrasound microbubble group was greater than that of the rAAV-sTRAIL group (P < 0.05). CONCLUSION: TRAIL has a potential role to inhibit e proliferation and induce apoptosis of human hepatocellular carcinoma cells. Ultrasound and microbubble echocontrast agent increase the transfection rate of rAAV vector into HCC cells.

[Clinical analysis of 60 cases with malignant gastrointestinal stromal tumors].

OBJECTIVE: To investigate the clinicopathological characteristics, and treatment of malignant gastrointestinal stromal tumors (MGIST). METHODS: Immunohistochemistry was used to detect CD117, CD34, S100, vimentin and SMA expressions. The postoperative curative effect was compared between the patients with or without imatinib treatment. RESULTS: Radical resection was performed in 60 cases. Twenty-two tumors with a mean diameter of 5.3 cm were potentially malignant, and 38 tumor with a mean diameter of 9.2 cm were malignant. Microscopical examination revealed haemorrhagia or necrosis, abundant tumor cells, heteromorphism and caryocinesia of the tumors. 54 Cases were CD117 positive, 53 cases CD34 positive, 48 cases vimentin positive, 27 cases S100 positiveì16 cases SMA positive. The two-year recurrence rate was 80.5% in the patients without postoperative imatinib treatment, significantly higher than 21.1% in the patients with postoperative imatinib treatment(P< 0.05). CONCLUSIONS: CD117 and CD34 markers are most valuable diagnostic indexes of MGIST, but its final diagnosis depends on pathology. Postoperative imatinib treatment is most effective to control recurrence and metastasis.