Pioglitazone, a peroxisome proliferator­activated receptor γ agonist, induces cell death and inhibits the proliferation of hypoxic HepG2 cells by promoting excessive production of reactive oxygen species.

Hypoxia is a hallmark of solid tumors. Hypoxic cancer cells adjust their metabolic characteristics to regulate the production of cellular reactive oxygen species (ROS) and facilitate ROS-mediated metastasis. Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that regulates the transcription of fatty acid metabolism-related genes that have a key role in the survival and proliferation function of hypoxic cancer cells. In the present study, mRNA expression in HepG2 cells under chemically induced hypoxia was assessed. The protein expression levels of hypoxia-inducible factor 1α (HIF-1α) were measured using western blotting. Following treatment with the PPARγ agonist pioglitazone, cell viability was assessed using a Cell Counting Kit-8 assay, whilst cell proliferation and death were determined using 5-ethynyl-2'-deoxyuridine incorporation staining, and calcein-acetoxymethyl ester and propidium iodide staining, respectively. Cellular ROS production was assessed using dihydroethidium staining. Cobalt chloride was used to induce hypoxia in HepG2 cells, which was evaluated using HIF-1α expression. The results revealed that the mRNA expression of PPARγ, CD36, acetyl-co-enzyme A dehydrogenase (ACAD) medium chain (ACADM) and ACAD short-chain (ACADS) was downregulated in hypoxic HepG2 cells. The PPARγ agonist pioglitazone decreased the cell viability of hypoxic HepG2 cells by inhibiting cell proliferation and inducing cell death. Following treatment with the PPARγ agonist pioglitazone, hypoxic HepG2 cells produced excessive ROS. ROS-mediated cell death induced by the PPARγ agonist pioglitazone was rescued with the antioxidant N-acetyl-L-cysteine. The downregulated mRNA expression of PPARγ, CD36, ACADM and ACADS was not reverted by a PPARγ agonist in hypoxic HepG2 cells. By contrast, the PPARγ agonist suppressed the mRNA expression of BCL2, which was upregulated in hypoxic HepG2 cells. In summary, the PPARγ agonist stimulated excessive ROS production to inhibit cell proliferation and increase the death of hypoxic HepG2 cells by decreasing BCL2 mRNA expression, suggesting a negative association between PPARγ and BCL2 in the regulation of ROS production in hypoxic HepG2 cells.

The addition of camrelizumab is effective and safe among unresectable hepatocellular carcinoma patients who progress after drug-eluting bead transarterial chemoembolization plus apatinib therapy.

OBJECTIVE: Camrelizumab synergizes with apatinib or transarterial chemoembolization via tumor immunity and chemosensitivity. This study aimed to investigate the efficacy and safety of camrelizumab plus apatinib with or without drug-eluting bead transarterial chemoembolization (DEB-TACE) in unresectable hepatocellular carcinoma (HCC) patients after progression to DEB-TACE plus apatinib. METHODS: Eighty-nine unresectable HCC patients accepted previous DEB-TACE plus apatinib therapy, then further received second-line camrelizumab plus apatinib with or without DEB-TACE treatment. Treatment responses were calculated at 3 months (M3) and 6 months (M6). Survival and treatment-related adverse events were documented. RESULTS: Objective response rate and disease control rate were 39.3% and 80.9% at M3; meanwhile, they were 22.4% and 54.1% at M6. Furthermore, the median progression-free survival (PFS) (95% confidence interval (CI)) was 7.0 (6.2-7.8) months with a 1-year PFS rate of 18.4%; the median overall survival (OS) (95% CI) was 17.0 (15.3-18.7) months with a 1-year OS rate of 73.9%. Multivariable Cox's proportional hazards regression analysis presented that 3-4 times (vs. 0 time) of DEB-TACE, apatinib dose duration> 4 months, and camrelizumab dose duration> 5 months independently predicted longer PFS (all P<0.05); meanwhile, declined ECOG PS score, new lesions as progression pattern, 1-2 and 3-4 times (vs. 0 time) of DEB-TACE, apatinib dose duration> 4 months independently predicted prolonged OS (all P<0.05). Moreover, treatment-related adverse events mainly included grade 1-2 fever, gastrointestinal reaction, fatigue, hand-foot skin reaction, and hypertension. CONCLUSION: After progression to DEB-TACE plus apatinib treatment, the addition of camrelizumab is effective and safe among unresectable HCC patients.

Nrf2-siRNA Enhanced the Anti-Tumor Effects of As2O3 in 5-Fluorouracil-Resistant Hepatocellular Carcinoma by Inhibiting HIF-1α/HSP70 Signaling.

Purpose: Chemoresistance is a major factor contributing to the failure of cancer treatment. The conventional chemotherapy agent 5-fluorouracil (5-FU) has been used for cancer treatment for decades. However, its use is limited in the treatment of hepatocellular carcinoma (HCC) due to acquired resistance. Nrf2 (NF-E2-related factor 2) is known to be associated with drug resistance across a wide range of cancer types. Also, since arsenic trioxide (As2O3) showed antitumor effects on HCC, the purpose of this study was to determine whether As2O3 and Nrf2-siRNA could inhibit HCC synergistically. Methods: We generated two separate 5-FU-resistant HCC cell lines (SNU-387/5-FU and Hep3B/5-FU). Western blotting was used to determine protein levels. An efficient lentiviral delivery system was used to establish stable knockdown or overexpression of Nrf2 and HIF-1α. In vitro and in vivo analyses of the effects of Nrf2 gene knockdown and As2O3 on 5-FU-resistant HCC cells were conducted. Results: The expression of Nrf2 was higher in the 5-FU-resistant HCC cell lines than in the parental cell lines. When coupled with Nrf2 knockdown, As2O3 treatment significantly decreased 5-FU-resistant SNU-387 and Hep3B cell viability, migration, and invasion, inactivated HIF-1α/HSP70 signaling, inhibited anti-apoptotic B-cell lymphoma (Bcl-2) activity, and increased the expression of pro-apoptotic Bcl-2-associated X protein (BAX) along with caspase-3. The synergistic effect was also confirmed using a 5-FU-resistant Hep3B mouse xenograft model in vivo. Conclusion: Nrf2 knockdown could improve the effect of As2O3 on reversing drug resistance in 5-FU-resistant HCC cells.

Covalent organic polymer induces apoptosis of liver cancer cells via photodynamic and photothermal effects.

The purpose of this study was to explore the photodynamic and photothermal effects of the supramolecular material Purp@COP and to test the anti-cancer effect on HepG2 cells in vitro. Materials and methods: Purp@COP is a covalent organic polymer (COP) with robust tailoring heteroatom incorporation, plentiful pore structure, and multiple functions similar to the metal-organic framework (MOF). Hepatocellular carcinoma cell line HepG2 was cultured with Purp@COP for 24 h and treated with near-infrared 808-nm laser 1 W/cm2 for 10 min. Cell Counting Kit-8 (CCK-8) assay, colony formation assay, live-dead cell fluorescence staining, and Annexin V/propidium iodide (PI) staining flow cytometry were performed to detect the viability, proliferation, and apoptosis of the HepG2 cells. Results: The supramolecular material Purp@COP exhibited significant photothermal performance under near-infrared 808-nm laser irradiation in vitro. With the treatment of Purp@COP and near-infrared 808-nm laser irradiation on HepG2 cells, cell viability and colony formation capacity were decreased, and the number and proportion of apoptotic cells were increased. Conclusions: The supramolecular material Purp@COP has both photothermal and photodynamic effects and can significantly induce cancer cell death and inhibit the proliferation of cancer cells in vitro.

Liposome quercetin enhances the ablation effects of microwave ablation in treating the rabbit VX2 liver tumor model.

OBJECTIVE: This study aimed to investigate whether liposomal quercetin (LQ) could enhance the effects of microwave ablation (MVA) in treating the rabbit VX2 liver tumor model. METHODS: Rabbits with VX2 liver tumors were randomly divided into three groups: intravenous LQ group (LQ group), MWA group and LQ combined with MWA (LQ + MWA) group. Five rabbits were randomly selected and sacrificed from each group at 12 h and on days 3, 7 and 14 of the operation. The tumor samples were detected and quantified by immunohistochemistry, Western blot, and reverse transcription polymerase chain reaction (RT-PCR). RESULTS: For up to 7 days, the coagulation necrosis volume (CV) of the LQ + MWA group was larger than that of MWA and LQ groups (p < 0.05). Fourteen days after the operation, the total tumor volume of the LQ + MWA group was smaller than that of the LQ group and the MWA group (p < 0.05). The survival time of the LQ + MWA group was significantly longer than that of the MWA and LQ groups (p < 0.01). Heat shock protein 70 (HSP70), hypoxia inducible factor-1 α (HIF-1 α), vascular endothelial growth factor (VEGF), tumor microvessel density (MVD) were lower in the LQ + MWA group than the MWA and LQ groups at 12 h, on days 3 and 7. At hour 12 and on days 3 and 7, HSP70 mRNA and HIF-1α mRNA expression of MWA group were significantly higher than that of the LQ and LQ + MWA groups (p < 0.001). At 12 h, and on days 3 and 7, apoptotic rate of tumor cells in LQ + MWA group was higher than that of the MWA and LQ groups (p < 0.05). At 12 h and on days 3, 7 and 14, the proliferation index of tumor cells in residual tumor in LQ + MWA group was lower than that in the MWA and LQ groups (p < 0.05). CONCLUSION: Preoperative infusion of LQ can significantly enhance the MWA effects of liver VX2 tumor, inhibit the excessive proliferation of residual tumor and angiogenesis, and decrease metastasis and prolong the survival period of experimental animals.

Drug-eluting bead transarterial chemoembolization followed by apatinib is effective and safe in treating hepatocellular carcinoma patients with BCLC stage C.

BACKGROUND: The present study aimed to evaluate the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) followed by apatinib in treating hepatocellular carcinoma (HCC) patients with Barcelona Clinic Liver Cancer (BCLC) stage C. METHODS: Totally, 110 HCC patients with BCLC stage C treated with DEB-TACE followed by apatinib were consecutively enrolled. Treatment response (including complete response rate (CR), objective response rate (ORR) and disease control rate (DCR)), survival data (progression-free survival (PFS), overall survival (OS)), and adverse events were documented during the follow-up. RESULTS: CR, ORR and DCR were 25.5%, 77.2% and 79.1% at 3 months, then were 29.1%, 59.1% and 71.0% at 6 months, respectively. Regarding survival, median PFS (95%CI) was 6.3 (5.0-7.7) months, meanwhile 1-year and 2-year PFS were 19.8% and 3.3%, respectively; median OS (95%CI) was 16.9 (10.2-23.7) months, then 1-year, 2-year and 3-year OS were 66.5%, 34.7% and 14.2%, respectively. Further subgroup analysis indicated that nodule size, Child-Pugh stage, Eastern Cooperative Oncology Group performance status score and level of portal vein invasion were negatively correlated with PFS or OS, which were further validated by univariate and multivariate Cox's regression analysis. Most adverse events by DEB-TACE and apatinib treatment were mild and well-tolerable. CONCLUSION: DEB-TACE followed by apatinib is effective and safe in treating BCLC stage C HCC patients, indicating its role as an acceptable option in HCC management.

Occurrence, Related Factors and Prognostic Value of Vascular Lake in Hepatocellular Carcinoma Patients Treated with Drug-Eluting Bead Transarterial Chemoembolization.

PURPOSE: The present study aimed to assess the prevalence of vascular lake (VL), its associated factors and correlation with prognosis in hepatocellular carcinoma (HCC) patients treated with drug-eluting bead transarterial chemoembolization (DEB-TACE). PATIENTS AND METHODS:  A total of 286 primary HCC patients (with 384 treated nodules) receiving DEB-TACE treatment were recruited, and their clinical characteristics were documented. The occurrence of VL was recorded, and treatment responses were assessed according to the modified response evaluation criteria in solid tumor (mRECIST).In terms of treatment response, the total response status (including CR, PR, SD and PD), objective response rate (ORR) and disease control rate (DCR) were elevated in VL patients compared to non-VL patients as well as in VL nodules compared to non-VL nodules. Liver function indexes and adverse events were assessed. Progression-free survival (PFS) and overall survival (OS) were evaluated with the last follow-up date of March 2020. RESULTS: The patient-based and nodule-based VL occurrence rates were 17.1% and 16.4%, respectively. Larger tumor size, pseudocapsules and smaller bead size were independently associated with VL occurrence. PFS and OS were more prolonged in VL patients than in non-VL patients, and VL independently correlated with better PFS and OS. For liver function, the liver function indexes before and after DEB-TACE were of no difference between VL patients and non-VL patients. Additionally, the incidences of adverse events were similar between VL patients and non-VL patients. CONCLUSION:  VL occurs in 17.1% of HCC patients treated with DEB-TACE, and it is correlated with larger tumor size, pseudocapsule, smaller bead size, more favorable treatment response and better survival.

PSMC2/ITGA6 axis plays critical role in the development and progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a type of malignant tumor with sixth highest incidence and causes the third most cancer-related deaths in the world, whose treatment is limited by the unclear molecular mechanism. Currently, the correlation between PSMC2 and HCC is still unclear. Herein, we found that the expression of PSMC2 in HCC tissues was significantly higher than normal tissues. We also discovered the significant association between PSMC2 expression and tumor infiltrate as well as tumor stage. Further investigations indicated that PSMC2 knockdown contributed to impaired proliferation, colony formation, migration, and enhanced cell apoptosis in HCC cells. Moreover, PSMC2 could also suppress tumorigenicity of HCC cells in vivo. Gene microarray analysis followed by ingenuity pathway analysis was performed for exploring downstream of PSMC2 and identified ITGA6 as a potential target. Furthermore, our study revealed that ITGA6 knockdown exhibited similar inhibitory effects with PSMC2 on HCC cells in vitro. More importantly, our results proved the direct interaction and showed the mutual regulation between PSMC2 and ITGA6, and that PSMC2 knockdown could significantly aggravate the inhibition of HCC by ITGA6 depletion. Based on these intriguing results, this is the first time ever that PSMC2 is pinpointed as a tumor promotor to interfere HCC development and progression via interacting with ITGA6 directly.

Arsenic trioxide-loaded CalliSpheres: In vitro study of drug release and antitumor activity, and in vivo study of pharmacokinetics, treatment efficacy and safety in liver cancer.

The aim of the present study was to investigate the arsenic trioxide (ATO) loading/releasing efficiency of CalliSphere beads (CBs), as well as the in vitro anticancer activity, in vivo pharmacokinetics, treatment efficacy and safety of ATO-eluting CBs in liver cancer. The ATO loading and releasing efficiencies in CBs were evaluated. Furthermore, cell viability, invasion, apoptosis, VEGF expression and MMP9 expression were determined in liver cancer cells treated with ATO-eluting CBs or ATO solution. Rabbit liver models were established and underwent TACE with ATO-eluting CBs or ATO/lipiodol emulsion. Subsequently, their ATO pharmacokinetics were determined and macroscopic/microscopic examinations were conducted. In vitro, CB-loaded ATO increased during 40 min with an optimal loading efficiency of 23.0±2.5%, and released ATO rapidly within the first 30 min (31.40±10.0%) then slowed down within the latter 48 h (47.20±4.70%). ATO-eluting CBs exhibited decreased cell viability to some extent and similar invasive cell count, apoptosis rate, VEGF and MMP9 levels compared with ATO solution at various concentrations and time-points. In vivo, ATO concentration was lower in plasma, but higher in tumor tissues, and necrosis was more complete in tumor tissue while milder in normal liver parenchyma after rabbit liver was embolized with ATO-eluting CBs compared with ATO/lipiodol emulsion. ATO-eluting CBs may be a novel and promising therapeutic option in treating liver cancer.

Combined use of microwave ablation and cell immunotherapy induces nonspecific immunity of hepatocellular carcinoma model mice.

Microwave ablation (MWA) has been widely used in the treatment of solid tumors. Studies have been less conducted on the efficacy of MWA used with cell immunotherapy in treating hepatocellular carcinoma (HCC). The current study aimed at exploring the efficacy of MWA in combination with cell immunotherapy in treating HCC. Hepa1-6 HCC mice were treated by MWA, blockade, or the combined therapy (MWA used with blockade), or left untreated. Survival rates of the mice were plotted by Kaplan-Meier Curve, followed by log-rank test. 25 days after the operation, surviving mice were monitored for tumor recurrence, and tumor volumes were calculated every 5 days. Immunohistochemistry and flow cytometry were performed to detect the numbers of CD4+ and CD8+ cells in the tumors and spleens of mice. The expressions of related cytokines were detected and measured by ELISPOT and ELISA. The results showed that MWA combined with anti-PD-1/anti-CTLA-4 not only increased the survival time, protected the mice against tumor recurrence, but also enhanced the intratumoral infiltration of cytotoxic T lymphocyte and systemic T-cell immune responses induced by MWA through activation of synergistically specific antitumor immunity. In addition, the combined therapy increased T-helper 1 cell (Th1-type) cytokines, but reduced Th2-type cytokines, resulting in the polarization of Th1 cells. T-cell immune responses of HCC cells were activated by MWA. In addition, the combined therapy of MWA and anti-PD-1/anti-CTLA-4 induced Th1-type immune response, and showed specific antitumor immunity.

Antitumor properties of arsenic trioxide-loaded CalliSpheres® microspheres by transarterial chemoembolization in VX2 liver tumor rabbits: suppression of tumor growth, angiogenesis, and metastasis and elongation of survival.

This study aimed to investigate the antitumor effect of arsenic trioxide (ATO)-loaded CalliSpheres® microspheres (CSM) by transarterial chemoembolization (TACE) in rabbits with VX2 liver tumors. A total of 120 VX2 liver tumor rabbits were randomized into four groups (N = 30 for each group), which received ATO-loaded CSM by TACE (CSM-ATO group), ATO by conventional TACE (cTACE-ATO group), transcatheter arterial embolization using CSM (TAE-CSM group), and saline arterial injection (control group). Five rabbits in each group were sacrificed at 12 h, 3 d, 7 d and 14 d, and then tumor proliferation, apoptosis, and angiogenesis/epithelial-mesenchymal transition (EMT) markers were detected. Tumor volume, metastasis status and ascites were assessed at 14 d. Ten rabbits in each group were observed until death for accumulating survival calculation. Tumor volume and ascites were decreased in the CSM-ATO group compared to the cTACE-ATO and TAE-CSM groups. Pulmonary, abdominal wall and omentum metastases were reduced while accumulating survival was increased in the CSM-ATO group compared to the TAE-CSM group. However, no difference in metastasis foci or survival between the CSM-ATO and cTACE-ATO groups was discovered. Meanwhile, tumor apoptosis was promoted while proliferation was suppressed in the CSM-ATO group compared to the cTACE-ATO and TAE-CSM groups. Additionally, HIF-1α, VEGF and microvessel density were decreased in the CSM-ATO group compared to the cTACE-ATO and TAE-CSM groups. Additionally, twist, N-cadherin, vimentin and MMP-9 were reduced while E-cadherin was enhanced in the CSM-ATO group compared to the cTACE-ATO and TAE-CSM groups. In conclusion, ATO-loaded CSM by TACE suppressed tumor growth, angiogenesis, and metastasis and elongated survival in VX2 liver tumor rabbits.