KIR2DL1-HLA signaling pathway: notable inhibition in the cytotoxicity of allo-NK cell against KG1A cell.

BACKGROUND: KIR2DL1 is an important member of killer cell immunoglobulin-like receptors (KIRs). It recognizes the C2 group of alleles exclusively and delivers signals that inhibit NK cell cytotoxicity. METHODS: In this study, NK cells were isolated by magnetic activated cell sorting (MACS) from peripheral blood of 12 healthy unrelated male donors. Flow cytometry (FCM) was used to evaluate the purity of NK cells and phenotypic KIR2DL1 expression on them. The lysis of KG1A and K562 cells by NK cells was analyzed in the lactate dehydrogenase (LDH) assay to investigate whether KIR2DL1 expression on NK cells would affect the cytotoxicity. RESULTS: Significant differences in KIR2DL1 frequency were noted among the donors (range, 27.14% - 92.49%). NK cells with lower KIR2DL1 expression exerted higher cytolytic activity against KG1A cells, whereas those with higher KIR2DL1 expression exerted significantly lower lysis against KG1A cells (R2 = 0.8169, p < 0.05). CONCLUSIONS: KIR2DL1 expression frequency was negatively correlated with the cytotoxicity of NK cells against KG1A cells. This study discovered that differential KIR2DL1 expression could positively affect the lytic activity of NK cells against KG1A cells, suggesting potential clinical value of KIR2DL1 selection in the treatment of acute myeloid leukemia (AML) patients.

Tribbles pseudokinase 3 (TRIB3) contributes to the progression of hepatocellular carcinoma by activating the mitogen-activated protein kinase pathway.

BACKGROUND: Tribble pseudokinase 3 (TRIB3) plays a key role in regulating the malignancy of many tumors. This study examined its function in cancer cells and explored the potential mechanisms of action. METHODS: The expression of TRIB3 was examined in hepatocellular carcinomas (HCCs) using The Cancer Genome Atlas (TCGA) database. A TRIB3 lentivirus with a flag label was constructed and transfected into Huh7 and Hep3B human hepatoma cell lines to generate cells that stably overexpress TRIB3. A small interfering RNA (siRNA) was designed to knockdown TRIB3 mRNA in HepG2 and Huh7. Cell viability and cell colony formation assays were conducted. Flow cytometry was performed to assess the cell cycle in cells overexpressing TRIB3. Western blotting were performed to examine the expression of (Mitogen-activated protein kinase, MAPKK) (MEK), phosphorylated-MEK (p-MEK), extracellular signal-regulated kinase (ERK), and p-MEK in cells with TRIB3 knockdown. The correlation between TRIB3 and SMARCD3 was assessed using co-immunoprecipitation assays and immunofluorescence. RESULTS: TRIB3 was significantly overexpressed in advanced grade HCC tissues and was closely correlated with poor prognosis. TRIB3 overexpression promoted the cell growth and cell cycle but had little effect on migration capabilities in Huh7 and Hep3B cells. Conversely, knockdown of TRIB3 had slow down the cell growth in Huh7 and HepG2 cells detected by CCK8 and colony formation assay. The expression of MEK and ERK at both the protein and mRNA levels were downregulated when TRIB3 was knocked down. The protein expression of p-ERK and p-MEK were also downregulated upon TRIB3 silencing. SMARCD3 is a transcript factor that is belongs to the SWI/SNF complex and has been shown to regulate many genes. Indeed, co-immunoprecipitation assays demonstrated that TRIB3 interacts with SMARCD3 in the nucleus, suggesting that it may regulate TRIB3 in HCCs. CONCLUSIONS: This study demonstrated that TRIB3 promotes the malignancy of HCC cells and its expression may be a potential diagnostic biomarker for HCC progression.

Nano-enabled coordination platform of bismuth nitrate and cisplatin prodrug potentiates cancer chemoradiotherapy via DNA damage enhancement.

The combination of chemotherapy and radiotherapy (chemoradiotherapy) is a promising strategy, extensively studied and applied clinically. Meanwhile, radiosensitizers play an important role in improving clinical radiotherapy therapeutic efficacy. There are still some disadvantages in practical applications, because radiosensitizers and drugs are difficult to deliver spatio-temporally to tumor sites and work simultaneously with low efficiency for DNA damage and repair inhibition, leading to an inferior synergistic effect. Herein, a suitable radiosensitizer of nano-enabled coordination platform (NP@PVP) with bismuth nitrate and cisplatin prodrug is developed by a simple synthetic route to improve the effectiveness of chemo-radiation synergistic therapy. When NP@PVP is internalized by a tumor cell, the bismuth in NP@PVP can sensitize radiation therapy (RT) by increasing the amount of reactive oxygen species generation to enhance DNA damage after X-ray radiation; meanwhile, the cisplatin in NP@PVP can inhibit DNA damage repair with spatio-temporal synchronization. NP@PVP is demonstrated to exhibit higher sensitization enhancement ratio (SER) of 2.29 and excellent tumor ablation capability upon irradiation in vivo in comparison with cisplatin (SER of 1.78). Our strategy demonstrates that the RT sensitization effect of bismuth and cisplatin based NP@PVP has great anticancer potential in chemo-radiation synergistic therapy, which is promising for clinical application.

Activation of MET promotes resistance to sorafenib in hepatocellular carcinoma cells via the AKT/ERK1/2-EGR1 pathway.

Sorafenib is an oral multikinase inhibitor that has become an established therapeutic approach in advanced hepatocellular carcinoma (HCC). However, the benefit of sorafenib in clinical therapy is often affected by drug resistance. Therefore, it is important to explore the mechanisms underlying sorafenib resistance and to develop individualized therapeutic strategies for coping with this problem. In this study, we found that addition of HGF to sorafenib-treated HCC cells activated MET and re-stimulated the downstream AKT and ERK1/2 pathways. Thereby, restored sorafenib-treated HCC cells proliferation, migration and invasion ability, and rescued cells from apoptosis. In addition, we found that HGF treatment of HCC cells induced early growth response protein (EGR1) expression, which is involved in sorafenib resistance. Importantly, the HGF rescued effect in sorafenib-treated HCC cells could be abrogated by inhibiting MET activation with PHA-665752 or by downregulating EGR1 expression with small interfering RNA (siRNA). Therefore, inhibition of the HGF/MET pathway may improve response to sorafenib in HCC, and combination therapy should be further investigated.

Combination of the neutrophil to lymphocyte ratio and the platelet to lymphocyte ratio as a useful predictor for recurrence following radiofrequency ablation of hepatocellular carcinoma.

The aim of the present study was to investigate the prognostic potential of a novel inflammation-based system, the combination of the neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) (CNP), for predicting the survival time of patients with hepatocellular carcinoma (HCC) who had received radiofrequency ablation (RFA). A total of 287 HCC patients treated with RFA were enrolled in the study. Patients with an elevated NLR (>2.58) and an elevated PLR (>131.78) were allocated a score of 2, and patients exhibiting one or neither of these characteristics were allocated a score of 1 or 0, respectively. The association between the CNP and various HCC clinicopathological factors, patterns of recurrence and prognoses were analyzed. The CNP was associated with liver cirrhosis (P=0.015), Child-Pugh class (P=0.024), total bilirubin level (P=0.028), neutrophil count (P<0.001), lymphocyte count (P<0.001) and platelet count (P<0.001). Compared with their low-CNP counterparts, patients with an elevated CNP were more likely to develop distant intrahepatic recurrence [52.3% (CNP 2) vs. 33.9% (CNP 0) and 34.6% (CNP 1), P=0.015; CNP 0 vs. CNP 1, P=0.922; CNP 1 vs. CNP 2, P=0.020] and extrahepatic metastasis [25.0% (CNP 2) vs. 7.6% (CNP 0) and 18.5% (CNP 1), P=0.003; CNP 0 vs. CNP 1, P=0.020; CNP 1 vs. CNP 2, P=0.309], and had shorter overall survival (OS) time (CNP 0 vs. CNP 1, P<0.001; CNP 1 vs. CNP 2, P<0.001) and recurrence-free survival (RFS; CNP 0 vs. CNP 1, P=0.012; CNP 1 vs. CNP 2, P=0.004). Moreover, multivariate analysis revealed that the CNP was superior to the NLR and the PLR as an independent prognostic marker of OS and RFS. Therefore, it was concluded that the CNP may represent a useful predictor for recurrence and prognosis in patients with HCC treated with RFA.