Hexokinase 2 confers radio-resistance in hepatocellular carcinoma by promoting autophagy-dependent degradation of AIMP2.

With technological advancements, radiotherapy (RT) has become an effective non-surgical treatment for hepatocellular carcinoma (HCC), comprehensively improving the local control rate of patients with HCC. However, some patients with HCC still experience radio-resistance, cancer recurrence, and distant metastasis following RT. Our previous study has revealed that hexokinase 2 (HK2), a potent oncogene, was overexpressed in radio-resistant HCC cell lines; however, its role in HCC radio-resistance remains elusive. Here, we confirmed the upregulation of HK2 in HCC tissue, which is related to unfavorable prognosis in patients with HCC, and demonstrated that HK2 exerts a radio-resistant role by attenuating apoptosis and promoting proliferation in HCC cell lines. HK2 downregulation combined with ionizing radiation showed an excellent synergistic lethal effect. Mechanistically, HK2 alleviated ionizing radiation-mediated apoptosis by complexing with pro-apoptotic protein aminoacyl tRNA synthetase complex interacting multifunctional protein 2 (AIMP2) while enhancing its autophagic lysosomal-dependent degradation, thereby increasing radio-resistance of HCC. Pharmacologically, ketoconazole, an FDA-approved antifungal drug, served as an inhibitor of HK2 and synergistically enhanced the efficacy of RT. Our results indicated that HK2 played a vital role in radio-resistance and could be a potential therapeutic target for improving RT efficacy in HCC.

Targeting MS4A4A on tumour-associated macrophages restores CD8+ T-cell-mediated antitumour immunity.

OBJECTIVE: Checkpoint immunotherapy unleashes T-cell control of tumours but is suppressed by immunosuppressive myeloid cells. The transmembrane protein MS4A4A is selectively highly expressed in tumour-associated macrophages (TAMs). Here, we aimed to reveal the role of MS4A4A+ TAMs in regulating the immune escape of tumour cells and to develop novel therapeutic strategies targeting TAMs to enhance the efficacy of immune checkpoint inhibitor (ICI) in colorectal cancer. DESIGN: The inhibitory effect of MS4A4A blockade alone or combined with ICI treatment on tumour growth was assessed using murine subcutaneous tumour or orthotopic transplanted models. The effect of MS4A4A blockade on the tumour immune microenvironment was assessed by flow cytometry and mass cytometry. RNA sequencing and western blot analysis were used to further explore the molecular mechanism by which MS4A4A promoted macrophages M2 polarisation. RESULTS: MS4A4A is selectively expressed by TAMs in different types of tumours, and was associated with adverse clinical outcome in patients with cancer. In vivo inhibition of MS4A4A and anti-MS4A4A monoclonal antibody treatment both curb tumour growth and improve the effect of ICI therapy. MS4A4A blockade treatment reshaped the tumour immune microenvironment, resulting in reducing the infiltration of M2-TAMs and exhausted T cells, and increasing the infiltration of effector CD8+ T cells. Anti-MS4A4A plus anti-programmed cell death protein 1 (PD-1) therapy remained effective in large, treatment-resistant tumours and could induce complete regression when further combined with radiotherapy. Mechanistically, MS4A4A promoted M2 polarisation of macrophages by activating PI3K/AKT pathway and JAK/STAT6 pathway. CONCLUSION: Targeting MS4A4A could enhance the ICI efficacy and represent a new anticancer immunotherapy.

[Study on risk factor of central venous catheter infection in ICU: 1 160 patients report].

OBJECTIVE: To analyze the etiology and risk factors of central venous catheter (CVCs) infections, and to explore the prophylaxis and treatment for catheter-related infections. METHODS: A retrospective study was conducted. The patients with CVCs admitted to intensive care unit (ICU) of Qianfoshan Hospital Affiliated to Shandong University from January 2000 to December 2016 were enrolled. The gender, age, catheter data and microorganism culture results of all patients were collected. The infection rate and the incidences of CVCs infection per 1 000 catheter days were calculated. The risk factors of CVCs infection were analyzed by Logistic regression. RESULTS: 1 160 patients were enrolled in 17 years [male 915, female 245, age 7-98 years, mean (71.8±17.5) years]. The incidences of CVCs infection per 1 000 catheter days were descended every 3 years (cases/1 000 days: 21.87, 24.50, 19.95, 12.64, 16.34, 12.40, χ2 = 38.851, P = 0.000). Of the 1 160 patients, 375 were positive for catheter culture, and 397 strains were cultured, among which 173 strains (43.58%) were Gram negative (G-), 130 strains (32.74%) of Gram positive (G+), and 94 strains of fungi (23.68%). Non-fermenting bacteria (Pseudomonas aeruginosa 11.59%, Acinetobacter baumannii 8.82%) was predominant in the G- bacteria, followed by Enterobacteria (Klebsiella pneumoniae 8.06%, Escherichia coli 2.02%); Staphylococcus spp. (Staphylococcus epidermidis 11.84%, Staphylococcus aureus 5.29%) was the main species of G+ bacteria; the main fungi were Candida tropicalis (9.07%) and Candida albicans (5.79%). The catheter infection rate of internal jugular vein, femoral vein and subclavian vein were 36.07% (22/61), 35.52% (119/335), 30.63% (234/764) respectively (χ2 =2.275, P = 0.099), the incidence of catheter infection of three vein insertion sites per 1 000 catheter days were 18.00, 17.71, 17.08 cases/1 000 days respectively (χ2 = 0.034, P = 0.714). The mean placement time of infected CVCs in situ was longer than that of non-infected CVCs (days: 20.80±11.68 vs. 17.64±10.77, t = 4.417, P = 0.000).The positive rate was lowest during 1-7 days of indwelling time (19.87%, 30/151). The infection rate was increased with long indwelling time. The positive rate was 44.44% (68/153) as indwelling time was over 30 days. The infection rate was significantly positively related to indwelling time (χ2 = 22.849, P = 0.000). Multiple Logistic regression analysis showed that the infection risk of femoral vein catheter was increased [odds ratio (OR) = 1.362, 95% confidence interval (95%CI) = 1.030-1.801, P = 0.030] as compared with that of subclavian vein catheter; the infection risk was increased with long indwelling time (OR = 1.306, 95%CI = 1.177-1.480, P = 0.000). CONCLUSIONS: G- are the major pathogens of CVCs infection. Femoral vein catheter and long indwelling time are the risk factors of CVCs infection.

[Detection the coinfection of Hantavirus and Orientia tsutsugamushi in primary cultured mite cells].

OBJECTIVE: To investigate whether HV and Ot can coexist in their host (Leptotrombidium scutellare). METHODS: Collecting the separate Leptotrombidium scutellare and the ones from mice in epidemic area. The cells of mites at larva, nymph, and adult stages were cultured and made into smear. In situ RT-PCR and PCR were used to detect and locate HV RNA and Ot DNA in the primary cultured cells. RESULTS: Positive signals of HV RNA and Ot DNA distributed mostly in epithelial cells of digestive system and ovary cells of larva and nymph. The positive rate increased by the generation of passages. CONCLUSION: Coinfection of HV and Ot did exist in wild Leptotrombidium scutellare.

[Study on the coinfection of Hantavirus and Orientia tsutsugamushi in tissue cell culture].

OBJECTIVE: To investigate the possibility of Hantavirus (HV) and Orientia tsutsugamushi (Ot) coinfection in their hosts. METHODS: HV and Ot were used to infect Vero E6 cells cultured in vitro singly, simultaneously or successively. Genes of HV and Ot were identified in different generation cells with RT-PCR. RESULTS: Five experiment groups of infected Vero E6 cells were tested, the results were as follows: HV and Ot were both positive in infected Vero E6 cells passaged 2 times and the positive rate increased following the passaged times in HV and Ot infection groups, simultaneously or successively. However, in the groups which were infected with HV and Ot separately, the gene of HV or Ot could be detected in infected Vero E6 cells passaged only once and the positive rate increased following the times of the passaged. The positive rate was higher in the singly infected groups than in those infected simultaneously or successively. CONCLUSION: Coinfection of HV and Ot did exist in the hosts while HV and Ot could inhibit each other in the initial infection stage.