The optimal timing of radiotherapy in the combination treatment of limited-stage extranodal natural killer/T-cell lymphoma, nasal type: an updated meta-analysis.

This study was designed to explore the relative efficacy and toxicity of upfront radiotherapy (RT) and late RT in combination treatments for patients with limited-stage extranodal natural killer/T-cell lymphoma nasal type (LS-ENKTL). We searched for clinical trials in the PubMed database that compared upfront RT with late RT in the combined treatment of patients with LS-ENKTL. We systematically evaluated the differences in survival, treatment response, and treatment-related adverse events (AEs) between these two groups. Ten retrospective studies with a total of 1752 patients were included. Upfront RT significantly prolonged the overall survival (OS) and progression-free survival (PFS) of patients compared to late RT in combination with chemotherapy (CT) (HR = 0.72, 95% CI 0.59-0.88, P = 0.001 for OS; HR = 0.57, 95% CI 0.41-0.79, P = 0.0007 for PFS). The complete remission (CR) rate in the upfront RT group was superior to that in the late RT group (HR = 1.61, 95% CI 1.09-2.37, P = 0.02). Patients experienced similar local recurrence-free survival (LRFS), objective response rates (ORR), and toxicity between these two arms (P > 0.05 for all) in the analysis of each subgroup. The survival benefit of upfront RT was not correlated with the RT dose, concurrent chemoradiotherapy (CCRT) (or not), or the CT regimen (P > 0.05 for all). Without compromises in terms of toxicity, RT dose, and treatment modality, upfront RT can significantly benefit OS, PFS, and CR compared to late RT in combination treatment. These findings verified that the upfront RT regimen is more suitable for patients with LS-ENKTL.

Low initial trough concentration of rituximab is associated with unsatisfactory response of first-line R-CHOP treatment in patients with follicular lymphoma with grade 1/2.

For follicular lymphoma (FL) with grade 1/2, the complete response (CR) rate of the first-line R-CHOP treatment was significantly low. In this study, we assessed the rationality of the administration of rituximab for FL patients with grade 1/2 based on concentration-response relationship analyses. Thus, we conducted a prospective pharmacokinetic (PK) study in 68 FL patients with grades 1-3 treated with R-CHOP at 21-day intervals. Plasma rituximab concentrations were quantified using ELISA and the population PK modeling was established with Phoenix® NLMETM. The first cycle trough concentration (C1-trough) of rituximab was a significant independent risk factor for achieving CR in matched-pair logistic regression analysis, rather than the concentrations in later cycles; the recommendatory minimum optimal C1-trough was 13.60 µg/mL. Patients with grade 1/2 had significantly lower C1-trough compared with grade 3 (12.21 µg/mL vs. 23.45 µg/mL, P < 0.001), only 30% patients with grade 1/2 could reach 13.60 µg/mL, compared with 91.67% in patients with grade 3, which was in accord with its unsatisfactory CR rates (43.33% vs. 76.32%). The stage indicating the tumor burden (the target) was a crucial influence factor for C1-trough, accounting for 40.70% of its variability, 70% patients with grade 1/2 were stage IV in this study, since the systemic therapy only started at the disseminated disease stage. The initial dose of 1800 mg was recommended by Monte Carlo simulation for patients with grade 1/2. In summary, low C1-trough accounted for low-grade FL's unsatisfactory CR rate, designing the first dosage of rituximab should be a very important component of individualized therapy for FL.

Platelet-derived alpha-granules are associated with inflammation in patients with NK/T-cell lymphoma-associated hemophagocytic syndrome.

Due to the variable overlap of multiple symptoms, accurate early diagnosis of NK/T-cell lymphoma-associated hemophagocytic syndrome (NK/T-LAHS) is difficult, making the prognosis extremely poor. Hemophagocytic syndrome (HPS) is now diagnosed primarily based on the hemophagocytic lymphohistiocytosis (HLH)-2004 diagnostic criteria, and platelet count is one of the baseline evaluations. However, in our study, the data showed that decreased platelets were not only a clinical feature of HPS but also the key cells that regulate inflammation by releasing α-granules containing upregulated platelet factor 4 (PF4) and downregulated platelet-derived growth factors (PDGFs). Furthermore, we found that angiopoietin-4 (ANG-4), which has significant differential expression, has been less reported, that may affect hematopoiesis and proinflammatory responses and can be used as diagnostic biomarkers together with PF4 and PDGFs.

A proposal for a prognostic index for non-nasal type natural killer/T cell lymphoma after asparaginase-based treatment.

In the era of asparaginase-based therapy for extranodal natural killer/T cell lymphoma (ENKTL), the clinical outcomes of ENKTL have notably improved. However, as a rare subtype of ENKTL, the therapeutic effect and prognostic factors of non-nasal type ENKTL remain unclear. Thus, we performed this study to analyze the clinical characteristics and to establish a prognostic model specifically for the non-nasal disease. We performed a retrospective study of consecutive patients newly diagnosed with non-nasal type ENKTL and mainly received asparaginase-based therapy at Sun Yat-sen University Cancer Center (SYSUCC) between January 2011 and December 2019, to analyze the prognostic factors and to propose a prognostic model. We validated the prognostic model in an independent cohort. In total, 98 non-nasal type ENKTL patients were included in the training cohort. Multivariate analyses showed that prognostic factors for OS were elevated LDH levels, involvement of bone marrow and serum total protein (TP) < 60 g/L. We developed a new prognostic model named the non-nasal type ENKTL prognostic index (NPI) by grouping the prognostic factors: group 1, no risk factors; group 2, one risk factor; and group 3, two or three risk factors, which were associated with 3-year OS rates of 84.1% (95% CI, 70.9-97.2), 46.8% (27.7-65.8), and 14.9% (0-32.9), respectively (P < 0.001). These results were validated and confirmed in an independent cohort. The new model is efficient in distinguishing non-nasal-type ENKTL patients with various outcomes in the contemporary era of asparaginase-based therapy.

Cancer cell-extrinsic STING shapes immune-active microenvironment and predicts clinical outcome in gastric cancer.

PURPOSE: The activation of cGAS-STING pathway can be triggered by cytosolic double-stranded DNA (dsDNA) in tumor and non-tumor compartments. We aim to assess the constitutive expression of dsDNA-cGAS-STING axis in different cellular contexts and compare their relative contribution to clinical outcomes. METHODS: A cohort of 154 cases of patients with newly diagnosed gastric cancer were enrolled in this study to evaluate the histo-score of cytosolic dsDNA, cGAS, and STING via immunohistochemistry as well as the types and densities of tumor-infiltrating immune cells. Kaplan-Meier method, multivariable regression, and receiver operating characteristic curve were implemented to analyze the prognostic efficacy of dsDNA-cGAS-STING axis in distinct compartments. RESULTS: The supra-normal concentration of cytosolic dsDNA correlated with the constitutive expression of cGAS-STING pathway in tumor compartments. In contrast to the lack of STING within cancer cells, the higher STING expression in non-tumor compartments indicated a transcellular cGAS-STING activation. Cancer cell-extrinsic STING was supported to potentiate nucleic acid immunity by sensing tumor-derived dsDNA fragments. Compartmental analyses also confirmed that the level of STING expressed in non-tumor cells was associated with the infiltration of protective immune cells, leading to the prolonged overall survival. Multivariate analysis further identified the independent prognostic value of cancer cell-extrinsic STING and its predictive accuracy could be significantly improved in combination with the immune cell infiltration. CONCLUSIONS: Cancer cell-extrinsic STING facilitates the remodeling of immune-active tumor microenvironment and acts as an independent prognostic factor in gastric cancer.

A study on the prevention of hemorrhage and perforation in patients with primary gastric diffuse large-B cell lymphoma during treatment with immunochemotherapy.

BACKGROUND: Stomach hemorrhage and perforation are very severe and common complications in patients with primary gastric diffuse large B-cell lymphoma (PG-DLBCL) during treatment with immunochemotherapy. However, no relevant clinical studies have been performed on the prevention of these serious complications. METHODS: Patients diagnosed with PG-DLBCL were enrolled in this retrospective study. The prevention group received standard rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) treatment without prednisone combined with antacids and anti-Helicobacter pylori (Hp) therapy. These patients received R-CHOP-based treatment until the complete recovery of gastric ulcers, as proven by gastroscopy. The control group received a standard R-CHOP regimen. Toxicity and survival were the main endpoints. RESULTS: A total of 52 patients received preventative treatment, while 146 patients did not. Among patients with stage I, II-1, and II-2 disease, the prevention group had a lower rate of hemorrhage and perforation (0/40) than the control group (10/78, p = 0.044). At a median follow-up time of 25 months, the 5-year event-free survival (EFS) rates were 97.1% in the prevention group and 66.1% in the control group (p = 0.025), and the 5-year overall survival (OS) rates were 100% and 72.0%, respectively (p = 0.021). However, the differences in the 5-year EFS and OS of patients with disseminated disease were not statistically significant. CONCLUSIONS: Preventative treatment can decrease the risk of hemorrhage and perforation in patients with localized PG-DLBCL during immunochemotherapy, leading to better EFS and OS in these patients. However, preventative treatment failed to reduce the risk of gastric hemorrhage and perforation and did not improve survival (EFS and OS) in advanced-stage patients.

Modified R-CODOX-M/IVAC chemotherapy regimens in Chinese patients with untreated sporadic Burkitt lymphoma.

OBJECTIVE: To characterize modified R-CODOX-M/IVAC-based chemotherapy to lower the severe adverse events in Chinese adult patients with sporadic Burkitt lymphoma. METHODS: We enrolled a retrospective cohort including 123 adult patients with untreated sporadic Burkitt lymphoma from August 2008 to September 2019 at Sun Yat-sen University Cancer Center. We studied a dose-modified and long-course R-CODOX-M/IVAC regimen utilizing a low dose of 1.0 g/m2/cycle cyclophosphamide, 2 g/m2/cycle methotrexate, 4,500 mg/m2/cycle ifosfamide, and 4.0 g/m2/cycle cytarabine. Forty-nine patients with low risk disease underwent 4-6 cycles of dose-modified R-CODOX-M-based chemotherapy. Seventy-four patients with high risk disease underwent 6-8 cycles of dose-modified alternating R-CODOX-M/IVAC regimens. RESULTS: The objective remission was 87.0%. The event-free survival rate and overall survival at 3 years were 81.2% and 92.1%, respectively. Major grade 3-4 adverse events included leukopenia (91.9%), anemia (58.5%), thrombocytopenia (73.2%), and febrile neutropenia (48.8%). A total of 26.0% and 37.4% of patients received red blood cell and platelet transfusions, respectively. We observed 4 cases (3.3%) of septic shock after chemotherapy. Two treatment-related deaths occurred from severe infection. CONCLUSIONS: The modified R-CODOX-M/IVAC chemotherapy regimen was effective for sporadic Burkitt lymphoma in the Chinese population, with a lower toxicity than standard regimens.

Combination of crizotinib and chemotherapy in patients with relapsed or refractory anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL).

Our aim was to explore the role of crizotinib, targeted anaplastic lymphoma kinase (ALK), on r/r systemic anaplastic large cell lymphoma (sALCL). The treated group prospectively screened 20 patients. After taking crizotinib in the first week, 16 patients who were tolerant and sensitive received the combination of crizotinib with chemotherapy. The control group included 27 patients receiving chemotherapy in the same hospital during the same period. The objective remission rates of the treated and control group were 81.3% and 74.1% (p = .869), respectively. The progression-free survival rates at two years in treated and control group were 68.7% and 45.0% (HR = 0.42, 95% CI 0.17-0.99, p < .05), respectively. The overall survival rates at two years in the treated and control group were 86.1% and 78.9% (p = .385, HR = 0.51, 95% CI 0.11-2.30), respectively. The main adverse events included elevated transaminase, diarrhea, and vision abnormalities. Thus, the combination of crizotinib with chemotherapy might be effective in ALK-positive and crizotinib sensitive r/r sALCL patients.

A New Immunological Prognostic Model Based on Immunohistochemistry for Extranodal Natural Killer/T-Cell Lymphoma Patients After Non-Anthracycline-Based Chemotherapy.

PURPOSE: Programmed death ligand 1 (PD-L1) has been proposed as an important prognostic factor in many types of cancer. However, the role of predicting the prognosis of PD-L1 in extranodal natural killer/T-cell lymphoma (ENKTL) was controversial. Combining other biomarkers might enhance its predictive power. This study aims to evaluate the prognostic value of PD-L1 in conjunction with tumor-infiltrating FoxP3+Tregs for ENKTL after non-anthracycline-based chemotherapy. PATIENTS AND METHODS: A total of 81 patients with ENKTL were included in this study. Clinicopathological characteristics were collected, and prognostic significance of PD-L1 in neoplastic cells (nPD-L1) and tumor-infiltrating FoxP3+Tregs were evaluated. RESULTS: Patients with nPD-L1-positive had significantly inferior overall survival (OS) and progression-free survival (PFS) compared with nPD-L1-negative (3-year OS, 37.2% vs 67.3%, p = 0.014; 3-year PFS, 31.0% vs 61.8%, p =0.010, respectively). Patients who had low FoxP3+Tregs had significantly inferior OS and PFS compared with high FoxP3+Tregs (3-year OS, 36.4% vs 63.0%, p = 0.004; 3-year PFS, 31.7% vs 56.3%, p = 0.020, respectively). The results of multivariate analysis showed that nPD-L1 positivity (HR 6.629, 95% CI 1.966-22.350, p=0.002) and low FoxP3+Tregs (HR 7.317, 95% CI 2.154-24.855, p=0.001) were independent predictors of inferior OS. Using these 2 variables, we constructed a new prognostic model that singled out 3 groups with different risk profiles: group 1, no adverse factors; group 2, 1 adverse factor; and group 3, 2 adverse factors. The 3-year OS rates of group 1, group 2, and group 3 were 93.3%, 46.6% and 20.8%, respectively (p<0.001), and the 3-year PFS rates were 86.7%, 40.8% and 15.0%, respectively (p=0.001). CONCLUSION: This study is the first to validate the prognostic value of nPD-L1 and tumor-infiltrating FoxP3+Tregs in ENKTL; the new immunological prognostic model might be used to stratify ENKTL patients in clinical trials for new therapeutic strategies.

A prospective, crossover randomized trial of the optimal timing for leucovorin rescue after high-dose methotrexate management in adult non-Hodgkin's lymphoma patients.

This study aimed to investigate the optimal time of leucovorin rescue for HDMTX in non-Hodgkin's lymphoma (NHL) patients. Ninety-eight patients treated with HDMTX were randomly assigned to receive leucovorin at either 18 or 24 h after initiation of HDMTX infusion during the first cycle and switched to the other mode in the second cycle. All courses achieved an efficacious MTX concentration. Compared to the 18th hour group, the 24th hour group exhibited an increase in incidence of thrombocytopenia (48% versus 34.7%, p = .036) and grade III/IV neutropenia (34.7% versus 21.4%, p = .039). No bleeding occurred and the incidence of fever with grade III/IV neutropenia was low with no difference observed between the two groups. We recommend that with the HDMTX generally used most adult patients with NHL may have greater therapeutic benefit and acceptable toxicity with their LV rescue started at 24 h instead of 18 h.

Colon cancer metastasis to the mandibular gingiva with partial occult squamous differentiation: A case report and literature review.

Metastasis is the primary cause of death among patients with colon cancer. However, the number of available studies regarding oral cavity metastases from colon cancer is currently limited. We herein report an unusual case of a 60-year-old male patient who developed an oral cavity metastasis from colon cancer. A total of 12 clinical case studies reporting colon cancer metastases to the mandibular gingival region were also reviewed, with the aim to elucidate the clinical and pathological characteristics of this disease entity in order to improve clinical diagnosis and treatment. It was demonstrated that patients with oral cavity metastases from colon cancer were predominantly in the sixth or seventh decades of life. The mandible was the main site of metastatic tumors to the oral cavity, while the occurrence of gingival metastases was comparatively rare. Moreover, the diagnoses of an oral metastatic tumor and primary colon cancer were often synchronous and were frequently accompanied with metastases to other organs. Several key aspects were suggested that should be accounted for when diagnosing colon cancer patients, including focusing attention to oral symptoms when examining cancer patients, utilizing a multidisciplinary approach for differential diagnosis and utilizing postoperative pathological examination to accurately diagnose the type of tumor and optimize the efficacy of treatment.

Research progress on circadian clock genes in common abdominal malignant tumors.

The circadian clock refers to the inherent biological rhythm of an organism, which, is accurately regulated by numerous clock genes. Studies in recent years have reported that the abnormal expression of clock genes is ubiquitous in common abdominal malignant tumors, including liver, colorectal, gastric and pancreatic cancer. In addition, the abnormal expression of certain clock genes is closely associated with clinical tumor parameters or patient prognosis. Studies in clock genes may expand the knowledge about the mechanism of occurrence and development of tumors, and may provide a new approach for tumor therapy. The present study summarizes the research progress in this field.

Hepatitis B virus X protein and hypoxia­inducible factor-1α stimulate Notch gene expression in liver cancer cells.

Increasing evidence has demonstrated that Notch genes, including Notch1, Notch2, Notch3 and Notch4, are involved in carcinogenesis. However, the expression and regulation of Notch genes in hepatocellular carcinoma (HCC) tissues have not been fully investigated. In the present study, immunohistochemical and quantitative real-time PCR (qPCR) analyses were performed to examine the expression of Notch genes in normal human liver, HBV-related HCC and paired peritumoral tissues. Additionally, qPCR and western blotting were utilized to investigate the impact of hepatitis B virus X protein (HBx) and hypoxia­inducible factor-1α (HIF-1α) on the regulation of Notch gene expression. The immunohistochemical and qPCR results showed that the expression levels of Notch1, Notch3 and Notch4 were significantly higher in HCC tissues than the levels in peritumoral and normal liver tissues. However, no significant difference in Notch2 expression was found between HCC and peritumoral tissues. Among the four Notch genes, immunohistochemical analyses found that only the increased level of Notch3 in HCC tissues was positively correlated with vascular invasion of liver cancer (P<0.05). Moreover, we found that overexpression of both HBx and HIF-1α increased the expression of Notch1, Notch3 and Notch4 in HepG2 and Bel-7404 cell lines. In summary, the present study demonstrated that Notch1, Notch3 and Notch4 were upregulated in HCC tissues and that HBx and HIF-1α may be the factors that cause the overexpression of Notch genes. Furthermore, the increased expression of Notch3 was closely related to the vascular invasiveness of HCC.

Melittin-Containing Hybrid Peptide Hydrogels for Enhanced Photothermal Therapy of Glioblastoma.

The design of biocompatible and efficacious anticancer biomaterials to achieve relatively low tumor recurrence rates is the main pursuit of cancer photothermal therapy (PTT). RADA16-I is a synthetic amphiphilic peptide with the sequence RADARADARADARADA that can self-assemble into a peptide nanofiber hydrogel. In this study, we synthesized a novel melittin-RADA32-indocyanine green (ICG) hydrogel ("MRI hydrogel"), which contains melittin in the peptide hydrogel backbone and ICG in the hydrogel matrix, for enhanced PTT of glioblastomas. The MRI hydrogel exhibited physiologic characteristics similar to those of the RADA16 hydrogel, while displaying concentration-dependent cytotoxicity to C6 glioma cells and photothermal effects. The in vivo biodistribution of the MRI hydrogel was visualized by near-infrared fluorescence and photoacoustic imaging. More importantly, in vivo PTT provided by the MRI hydrogel significantly reduced the tumor size and the tumor recurrence rate compared with the RADR16-ICG hydrogel and other controls, suggesting a synergistic effect of MRI hydrogel-carried melittin and ICG-based PTT treatment. Thus, MRI provides an alternative tool for the safe and efficient PTT treatment of tumors.

Low heme oxygenase-1 expression promotes gastric cancer cell apoptosis, inhibits proliferation and invasion, and correlates with increased overall survival in gastric cancer patients.

Heme oxygenase-1 (HO-1) plays a key role in anti-oxidation, anti-apoptosis, and anti-proliferation in various types of cancers. However, the relationship between HO-1 expression and gastric cancer development remains largely unknown. In this study, the protein expression of HO-1 in human gastric cancer was measured by immunohistochemistry on paraffin sections of 89 paired gastric carcinoma tissues and adjacent non-cancer tissues. The correlation of HO-1 expression with 5-year overall survival rate was estimated. The effects of decreased HO-1 expression by two strands of small interfered RNAs (siRNAs) on cell apoptosis, proliferation, and invasion of gastric cancer cell lines were examined by flow cytometry, the MTT assay, and the cell migration assay, respectively. High expression of HO-1 was detected in 11.2% (10/89) of gastric carcinoma tissues, compared with 1.1% (1/89) in matched adjacent normal tissues, and correlated with a decreased survival rate in gastric cancer patients. There were no significant correlations between HO-1 expression and clinical characteristics. Downregulation of HO-1 expression using two strands of siRNAs promoted apoptosis and inhibited the proliferation and invasion of two gastric cancer cell lines, SGC7901 and MKN-28 cells. This study demonstrated that HO-1 plays a vital role in the development of gastric cancer and may serve as a therapeutic target of this type of cancer.

Clinicopathological and prognostic significance of hypoxia-inducible factor-1 alpha in lung cancer: a systematic review with meta-analysis.

Hypoxia-inducible factor-1 alpha (HIF-1α) plays a vital role in the initiation, evaluation and prognosis in lung cancer. The prognostic value of HIF-1α reported in diverse study remains disputable. Accordingly, a meta-analysis was implemented to further understand the prognostic role of HIF-1α in lung cancer. The relationship between HIF-1α and the clinicopathological characteristics and prognosis of lung cancer were investigated by a meta-analysis. PubMed and Embase were searched from their inception to January 2015 for observational studies. Fixed-effects or random-effects meta-analyses were used to calculate odds ratios and 95% confidence intervals of different comparisons. A total of 20 studies met the criteria. The results showed that HIF-1α expression in lung cancer tissues was significantly higher than that in normal lung tissues. Expression of HIF-1α in patients with squamous cell carcinoma was significantly higher than that of patients with adenocarcinomas. Similarly, non-small cell lung cancer (NSCLC) patients had higher HIF-1α expression than small cell lung cancer (SCLC) patients. Moreover, lymph node metastasized tissues had higher HIF-1α expression than non-lymph node metastasized tissues. A high level HIF-1α expression was well correlated with the expression of vascular endothelial growth factor and epidermal growth factor receptor in the NSCLC. Notably, NSCLC or SCLC patients with positive HIF-1α expression in tumor tissues had lower overall survival rate than patients with negative HIF-1α expression. It was suggested that HIF-1α expression may be a prognostic biomarker and a potential therapeutic target for lung cancer.

Evaluation of HO-1 expression, cellular ROS production, cellular proliferation and cellular apoptosis in human esophageal squamous cell carcinoma tumors and cell lines.

Patients with esophageal squamous cell carcinoma (ESCC) have a poor prognosis. However, the related mechanisms are unclear, thus we investigated the expression of HO-1 in ESCC tissue and explored possible mechanisms of tumor progression. Expression of HO-1 was examined by immunohistochemistry in 143 ESCC tumors. The correlation of HO-1 with clinicopathological characteristics was also examined. Two human ESCC cell lines, TE-13 and Eca109 were studied. Silencing of cell line HO-1 by specific small interfering RNA (siRNA) was evaluated using real-time quantitative PCR. Cell line viability, apoptosis and intracellular levels of reactive oxygen species (ROS) after transfection were determined using MTT and flow cytometry, respectively. HO-1, Bax, Bcl-2 and A-caspase-3/-9 expression was evaluated using western blot analyses. We found that HO-1 was expressed in 58 of 143 ESCC tumors, mainly in the cytoplasm. There was a significant association between HO-1 expression and tumor grade (P<0.001). Knockdown of HO-1 expression in cell lines was associated with significantly decreased cellular proliferation (P<0.05) and a higher rate of apoptosis (P<0.001) 48 h after treatment. Treatment of the cell lines with the ROS inhibitor N-acetylcysteine abrogated this effect. Knockdown of HO-1 was associated with increased A-caspase-3 and -9 expression, but no change in Bax or Bcl-2 expression or Bax/Bcl-2 ratio was observed. Thus, the present study identified that ESCC tumors frequently expressed HO-1. Knockdown of HO-1 promoted apoptosis through activation of a ROS-mediated caspase apoptosis pathway.

Hepatitis B virus induces hypoxia-inducible factor-2α expression through hepatitis B virus X protein.

A growing number of studies suggest that the hepatitis B virus X protein (HBx) enhances the protein stability of the hypoxia-inducible factor-1α (HIF-1α). However, the relationship between hepatitis B virus (HBV), HBx and hypoxia-inducible factor-2α (HIF-2α) has not yet been fully elucidated. Immunohistochemical analysis was employed to detect the expression of HIF-2α in normal liver, HBV-related chronic hepatitis, and HBV-related and non-HBV-related hepatocellular carcinoma (HCC) tissues. Quantitative real­time PCR (qPCR) and western blotting were used to investigate the impact of HBV and HBx on the expression of HIF­2α. Immunoprecipitation and immunofluorescence were applied to explore the underlying mechanisms. The HIF­2α expression was found to be higher in HBV­related chronic hepatitis tissues than in normal liver tissues. Furthermore, it was higher in HBV­related HCC tissues and HBV­integrated HepG2 cells than in the corresponding non­HBV­related HCC tissues and HepG2 cells. Both HBV and HBx enhanced the protein stability of HIF­2α. HBx­mediated upregulation of HIF­2α resulted mainly from an inhibition of the degradation of HIF­2α due to the binding of HBx to the von Hippel­Lindau protein (pVHL). In addition, HBx upregulated the expression of HIF­2α by activating the NF­κB signaling pathway. Thus, the present study identified that HBV induces the HIF­2α expression through its encoded protein HBx. This upregulates the HIF-2α expression by binding to the pVHL activating the NF-κB signaling pathway.