Metformin exhibits the anti-proliferation and anti-invasion effects in hepatocellular carcinoma cells after insufficient radiofrequency ablation

Mechanisms and therapeutic strategies to combat the recurrence and progression of hepatocellular carcinoma after thermal ablation

Thermal ablation (TA), including radiofrequency ablation (RFA) and microwave ablation (MWA), has become the main treatment for early-stage hepatocellular carcinoma (HCC) due to advantages such as safety and minimal invasiveness. However, HCC is prone to local recurrence, with more aggressive malignancies after TA closely related to TA-induced changes in epithelial-mesenchymal transition (EMT) and remodeling of the tumor microenvironment (TME). According to many studies, various components of the TME undergo complex changes after TA, such as the recruitment of innate and adaptive immune cells, the release of tumor-associated antigens (TAAs) and various cytokines, the formation of a hypoxic microenvironment, and tumor angiogenesis. Changes in the TME after TA can partly enhance the anti-tumor immune response; however, this response is weak to kill the tumor completely. Certain components of the TME can induce an immunosuppressive microenvironment through complex interactions, leading to tumor recurrence and progression. How the TME is remodeled after TA and the mechanism by which the TME promotes HCC recurrence and progression are unclear. Thus, in this review, we focused on these issues to highlight potentially effective strategies for reducing and preventing the recurrence and progression of HCC after TA.

Antitumor Activity of Metformin Combined with Locoregional Therapy for Liver Cancer: Evidence and Future Directions

This article aimed to examine the effect of metformin use on improving outcomes after liver-directed therapy in patients with HCC and identify future directions with the adjuvant use of and potential therapeutic agents that operate on similar mechanistic pathways. Databases were queried to identify pertinent articles on metformin's use as an anti-cancer agent in HCC. Eleven studies were included, with five pre-clinical and six clinical studies. The mean overall survival (OS) and progression-free survival were both higher in the locoregional therapy (LRT) + metformin-treated groups. The outcome variables, including local tumor recurrence rate, reduction in HCC tumor growth and size, tumor growth, proliferation, migration and invasion of HCC cells, HCC cell apoptosis, DNA damage, and cell cycle arrest, showed favorable outcomes in the LRT + metformin-treated groups compared with LRT alone. This systemic review provides a strong signal that metformin use can improve the tumor response after locoregional therapy. Well-controlled prospective trials will be needed to elucidate the potential antitumor effects of metformin and other mTOR inhibitors.

Engine shutdown: migrastatic strategies and prevention of metastases

Most cancer-related deaths among patients with solid tumors are caused by metastases. Migrastatic strategies represent a unique therapeutic approach to prevent all forms of cancer cell migration and invasion. Because the migration machinery has been shown to promote metastatic dissemination, successful migrastatic therapy may reduce the need for high-dose cytotoxic therapies that are currently used to prevent the risk of metastatic dissemination. In this review we focus on anti-invasive and antimetastatic strategies that hold promise for the treatment of solid tumors. The best targets for migrastatic therapy would be those that are required by all forms of motility, such as ATP availability, mitochondrial metabolism, and cytoskeletal dynamics and cell contractility.

Progression of hepatocellular carcinoma after radiofrequency ablation: Current status of research

Hepatocellular carcinoma (HCC) remains an important disease for health care systems in view of its high morbidity, mortality, and increasing incidence worldwide. Radiofrequency ablation (RFA) is preferred to surgery as a local treatment for HCC because it is safer, less traumatic, less painful, better tolerated, causes fewer adverse reactions, and allows more rapid postoperative recovery. The biggest shortcoming of RFA when used to treat HCC is the high incidence of residual tumor, which is often attributed to the vascular thermal deposition effect, the wide infiltration zone of peripheral venules, and the distance between satellite foci and the main focus of the cancer. Recurrence and progression of the residual tumor is the most important determinant of the prognosis. Therefore, it is important to be aware of the risk of recurrence and to improve the efficacy of RFA. This review summarizes the relevant literature and the possible mechanisms involved in progression of HCC after RFA. Current studies have demonstrated that multimodal treatments which RFA combined with other anti-cancer approaches can prevent progression of HCC after RFA.

HIF-2α regulates proliferation, invasion, and metastasis of hepatocellular carcinoma cells via VEGF/Notch1 signaling axis after insufficient radiofrequency ablation

Background and Aims

Although insufficient radiofrequency ablation (RFA) promotes the recurrence and metastasis of liver cancer, the underlying mechanism remains unclear. This study aimed to investigate the role and mechanism of HIF-2α in hepatocellular carcinoma cells (HCCs) after Insufficient RFA.

Methods

We established a model of insufficient RFA in MHCC97H hepatoma cells and screened for stable sublines. We inhibited HIF-2α expression in the Insufficient RFA group using PT2385 and assessed the resulting changes in proliferation and biological function of HCCs. Cell viability and proliferation were detected by the MTT method, and scratch and Transwell chamber invasion tests detected migration and invasion abilities of HCCs. The mRNA and protein expression levels of VEGF, HIF-2α, and Notch1 were detected using qPCR, immunofluorescence, and western blotting.

Results

Compared with normal HCCs without RFA treatment, insufficient RFA enhanced the proliferation and invasion abilities of hepatocellular carcinoma subline MHCC97H (P < 0.001), as well as their migration ability (P = 0.046). The HIF-2α-specific inhibitor PT2385 downregulated the migration (P = 0.009) and invasion (P < 0.001) of MHCC97H cells but did not affect cell proliferation (P > 0.05). Insufficient ablation increased the mRNA and protein expression of VEGF, HIF-2α, and Notch1 in HCCs, whereas inhibition of HIF-2α reversed these changes.

Conclusions

Insufficient RFA increases the proliferation, migration, and invasion of HCCs via the HIF-2α/VEGF/Notch1 signaling axis; HIF-2α is a potential target for novel treatments of HCC after insufficient RFA.

Metformin administration is associated with enhanced response to transarterial chemoembolization for hepatocellular carcinoma in type 2 diabetes patients

Transarterial chemoembolization (TACE) is often used as a locoregional therapy for early hepatocellular carcinoma (HCC) when local ablation or resection are not feasible, but incomplete response and recurrence are commonly observed. In this study, we sought to determine the association between metformin administration and TACE outcomes for single nodular HCC in patients with type 2 diabetes mellitus (T2DM). The retrospective cohort analysis included 164 T2DM patients with single nodular HCC who underwent TACE as an initial treatment, and 91 were exposed to metformin before and after TACE. Propensity score (PS) matching was used to balance covariates. Logistic regression analysis was used to determine the predictors of tumor response after TACE, and Cox regression analysis assessed independent predictors of local tumor recurrence (LTR) in patients with complete response after TACE. Metformin use was associated with significantly higher objective response rate (ORR) in the overall and PS-matched cohort (79.1% vs. 60.3 and 78.7% vs. 57.5%; p = 0.008 and p = 0.029, respectively). Logistic regression analysis showed that metformin use was an independent predictor of ORR in all and PS-matched patients (odds ratio = 2.65 and 3.06; p = 0.016 and 0.034, respectively). Cox regression analysis showed metformin administration was an independent predictor for lower LTR in all and PS-matched patients (hazard ratio = 0.28 and 0.27; p = 0.001 and 0.007, respectively). Metformin administration is associated with better initial response and lower local recurrence after TACE for single nodular HCC in T2DM.

An Overview of Hepatocellular Carcinoma After Insufficient Radiofrequency Ablation

Radiofrequency ablation (RFA) is a commonly used treatment for hepatocellular carcinoma (HCC), however, various complex conditions in clinical practice may lead to insufficient radiofrequency ablation (IRFA), allowing residual HCC to survive. In clinical practice and laboratory models, IRFA plays an important role in rapid tumor progression. Therefore, targeting the residual HCC and avoiding IRFA were worthwhile methods. A deeper understanding of IRFA is required; IRFA contributes to the improvement of proliferative activity, migration rates, and invasive capacity, and this may be due to the involvement of multiple complex processes or proteins, including epithelial mesenchymal transitions (EMTs), cancer stem cells (CSCs), autophagy, heat shock proteins (HSPs), changes of non-tumor cells and extracellular matrix, altered immune microenvironment, hypoxia-inducible factors (HIFs), growth factors, epigenetic alterations, and metabolic reprogramming. We focus on the processes of the above mechanisms and possible therapeutic approach, with a review of the literature. Additionally, we recapitulated the construction methods of various experimental models of IRFA (in vivo and in vitro).

Ophiopogonin‑B targets PTP1B to inhibit the malignant progression of hepatocellular carcinoma by regulating the PI3K/AKT and AMPK signaling pathways

Ophiopogonin‑B (OP‑B) is a bioactive component from the root of Ophiopogon japonicus, which can exert anticancer effects on multiple malignant tumors. The present study aimed to uncover the effects of OP‑B on hepatocellular carcinoma (HCC) and the underlying mechanisms. An HCC‑xenografted mouse model was established and subsequently treated with OP‑B (15 and 75 mg/kg) to observe the effects of OP‑B on HCC progression and protein tyrosine phosphatase 1B (PTP1B) expression in vivo. The HCC cell line MHCC97‑H was transfected with either PTP1B overexpression (Ov)‑PTP1B or empty vector control, and then exposed to different concentrations of OP‑B. Subsequently, PTP1B expression, cell viability, proliferation, apoptosis, migration, invasion and angiogenesis were evaluated by western blotting, reverse transcription‑quantitative PCR, Cell Counting Kit‑8, colony formation, TUNEL staining, wound healing, Transwell and tube formation assays. The expression of phosphatidylinositol 3 kinase (PI3K)/AKT and adenosine 5'‑monophosphate‑activated protein kinase (AMPK) was also assessed by western blot assay. The results showed that OP‑B inhibited tumor growth and the expression of Ki67, CD31, VEGFA and PTP1B in HCC xenograft model. The expression of PTP1B in HCC cells was also inhibited by OP‑B in a concentration‑dependent manner. Results from the in vitro studies revealed that OP‑B suppressed cell proliferation, migration, invasion and angiogenesis, and promoted apoptosis of HCC cells. However, PTP1B overexpression reversed the effect of OP‑B on HCC cells. PI3K/AKT was inactivated and AMPK was activated by OP‑B exposure in HCC cells, and PTP1B overexpression blocked these effects. In conclusion, OP‑B effectively inhibited the progression of HCC both in vivo and in vitro. These effects may depend on downregulating PTP1B expression, thereby inactivating the PI3K/AKT pathway and activating the AMPK pathway.

Role of metformin in the diagnosis, prevention, and treatment of hepatocellular carcinoma

Hepatocellular carcinoma is one of the most common malignant tumors in the world. Although there are many options for the treatment of hepatocellular carcinoma, such as surgical resection, interventional therapy, radiotherapy, chemotherapy, targeted therapy and liver transplantation, the poor therapeutic effect seriously reduces the quality of life for patients and also increases the social and economic burden. Metformin is originally used as the first-line drug for type 2 diabetes, but it has been found to play a certain effect in the prevention and treatment of malignant tumor. The potential roles of metformin against hepatocellular carcinoma, such as regulation of the microenvironment, proliferation signal pathway, metabolism, invasion and metastasis, apoptosis, autophagy, and epigenetics of hepatoma cells. It provides a new choice for the prevention and treatment of hepatocellular carcinoma.

Combination of Ablation and Immunotherapy for Hepatocellular Carcinoma: Where We Are and Where to Go

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide and is increasing in incidence. Local ablative therapy plays a leading role in HCC treatment. Radiofrequency (RFA) is one of the first-line therapies for early local ablation. Other local ablation techniques (e.g., microwave ablation, cryoablation, irreversible electroporation, phototherapy.) have been extensively explored in clinical trials or cell/animal studies but have not yet been established as a standard treatment or applied clinically. On the one hand, single treatment may not meet the needs. On the other hand, ablative therapy can stimulate local and systemic immune effects. The combination strategy of immunotherapy and ablation is reasonable. In this review, we briefly summarized the current status and progress of ablation and immunotherapy for HCC. The immune effects of local ablation and the strategies of combination therapy, especially synergistic strategies based on biomedical materials, were discussed. This review is hoped to provide references for future researches on ablative immunotherapy to arrive to a promising new era of HCC treatment.

The Clinical Value of Postoperative Transarterial Chemoembolization for Resectable Patients with Intermediate Hepatocellular Carcinoma After Radical Hepatectomy: a Propensity Score-Matching Study

BACKGROUND AND AIMS

Surgical resection for patients with intermediate hepatocellular carcinoma (HCC) is preferred in China, but the prognosis remains far from satisfactory. Postoperative transarterial chemoembolization (p-TACE) has been conducted prevalently to prevent recurrence, but its efficacy remains controversial. Hence, we collected the data from primary liver cancer big data (PLCBD) to investigate the clinical value of p-TACE for patients with intermediate HCC and identify the potential beneficiaries.

METHODS

Patients who were diagnosed with intermediate HCC between December 2012 and December 2015 were identified through the PLCBD. Disease-free survival (DFS) of patients who received p-TACE or not following radical resection was evaluated using Kaplan-Meier survival curves before and after 1:1 propensity scoring match (PSM). Subgroup analysis was conducted stratified by risk factors associated with recurrence.

RESULTS

A total of 325 intermediate HCC patients receiving radical resection were eligible in this study, including 123 patients in the p-TACE group and 202 in the non-TACE group. Median DFS in the p-TACE group was significantly longer than in the non-TACE group (23.3 months vs. 18.0 months, P = 0.016) in the whole cohort with no severe complicates, which was confirmed in a well-matched cohort (17.4 months vs. 23.3 months, P = 0.012). In addition, p-TACE was identified as an independent risk factors of DFS by multivariate Cox regression analysis before and after PSM (both P < 0.05). After adjusting for other prognostic variables, patients were found to significantly benefit from p-TACE in DFS if they were male, or had hepatitis, diabetes, cirrhosis, AFP ≤ 400 ng/ml, anatomic hepatectomy, no severe surgical complication, no intraoperative transfusion, tumor number = 2, differentiation grading III, capsule, or had no transfusion (all P < 0.05).

CONCLUSION

With the current data, we concluded that p-TACE was safe and efficient for the patients with intermediate HCC following radical resection, and male patients with hepatitis, diabetes, cirrhosis, AFP ≤ 400 ng/ml, anatomic hepatectomy, no severe surgical complication, no intraoperative transfusion, tumor number = 2, differentiation grading III, and capsule would benefit more from p-TACE.

Mechanisms of metformin inhibiting cancer invasion and migration

Cancer currently ranks among the leading causes of death globally. Cancer invasion and metastasis transform locally grown cancers to a systemic and life-threatening disease, which accounts for the most significant challenge in cancer treatment. Recent studies showed that Metformin, the most commonly used first-line oral drug for the treatment of type 2 diabetes (T2DM), could prevent and treat various cancers. Moreover, multiple evidence suggested that metformin inhibited cancer invasion and metastasis, which could improve the prognosis of cancer patients administrated with metformin. To better understand the anti-cancer role of metformin, the present review summarized the potential mechanisms of inhibiting cancer invasion and metastasis by metformin, including AMPK signaling pathway, EMT signaling pathway, epigenetic modification and so on. However, multiple problems remain unresolved and more clinical trials are needed to prove the inhibition of cancer invasion and metastasis by metformin.

The Role of AMP-Activated Protein Kinase as a Potential Target of Treatment of Hepatocellular Carcinoma

Background: Hepatocellular carcinoma (HCC) is the fifth most frequent cancer worldwide with a very high recurrence rate and very dismal prognosis. Diagnosis and treatment in HCC remain difficult, and the identification of new therapeutic targets is necessary for a better outcome of HCC treatment. AMP-Activated Protein Kinase (AMPK) is an essential intracellular energy sensor that plays multiple roles in cellular physiology and the pathological development of chronic diseases. Recent studies have highlighted the important regulation of AMPK in HCC. This review aims to comprehensively and critically summarize the role of AMPK in HCC. Methods: Original studies were retrieved from NCBI database with keywords including AMPK and HCC, which were analyzed with extensive reading. Results: Dysregulation of the kinase activity and expression of AMPK was observed in HCC, which was correlated with survival of the patients. Loss of AMPK in HCC cells may proceed cell cycle progression, proliferation, survival, migration, and invasion through different oncogenic molecules and pathways. Conclusions: We identified several AMPK activators which may possess potential anti-HCC function, and discussed the clinical perspective on the use of AMPK activators for HCC therapy.

Anti-proliferative and anti-apoptotic potential effects of epigallocatechin-3-gallate and/or metformin on hepatocellular carcinoma cells: in vitro study

The effects of epigallocatechin-3-gallate (EGCG) and metformin single treatment have been tested against hepatocellular carcinoma (HCC). This study aimed to assess the combination effects of EGCG and metformin on proliferation and apoptosis of HepG2cells and identified new potential molecular targets. The effect of EGCG and metformin against cell proliferation in HepG2 was determined using MTT assay. Reverse transcription polymerase chain reaction was applied to examine the gene expression of cyclin D1, lncRNA-AF085935, caspase-3, survivin and VEGF. The level of protein expression of glypican-3 was assessed by western blot. In HepG2 cells, EGCG and metformin combination treatment exhibited high significant effect against tumor proliferation. It significantly reduced cyclin D1, lncRNA-AF085935, glypican-3 and promoted apoptosis through increasing caspase3 and decreasing survivin compared to control cells. Moreover, EGCG and metformin treated cells showed decreased expression levels of VEGF. Our study provided new insights of the anticarcinogenic effects of EGCG and metformin on HCC through their effects on glypican-3 and lncRNA-AF085935.

Metformin triggers the intrinsic apoptotic response in human AGS gastric adenocarcinoma cells by activating AMPK and suppressing mTOR/AKT signaling

Metformin is commonly used to treat patients with type 2 diabetes and is associated with a decreased risk of cancer. Previous studies have demonstrated that metformin can act alone or in synergy with certain anticancer agents to achieve anti-neoplastic effects on various types of tumors via adenosine monophosphate-activated protein kinase (AMPK) signaling. However, the role of metformin in AMPK-mediated apoptosis of human gastric cancer cells is poorly understood. In the current study, metformin exhibited a potent anti-proliferative effect and induced apoptotic characteristics in human AGS gastric adenocarcinoma cells, as demonstrated by MTT assay, morphological observation method, terminal deoxynucleotidyl transferase dUTP nick end labeling and caspase-3/7 assay kits. Western blot analysis demonstrated that treatment with metformin increased the phosphorylation of AMPK, and decreased the phosphorylation of AKT, mTOR and p70S6k. Compound C (an AMPK inhibitor) suppressed AMPK phosphorylation and significantly abrogated the effects of metformin on AGS cell viability. Metformin also reduced the phosphorylation of mitogen-activated protein kinases (ERK, JNK and p38). Additionally, metformin significantly increased the cellular ROS level and included loss of mitochondrial membrane potential (ΔΨm). Metformin altered apoptosis-associated signaling to downregulate the BAD phosphorylation and Bcl-2, pro-caspase-9, pro-caspase-3 and pro-caspase-7 expression, and to upregulate BAD, cytochrome c, and Apaf-1 proteins levels in AGS cells. Furthermore, z-VAD-fmk (a pan-caspase inhibitor) was used to assess mitochondria-mediated caspase-dependent apoptosis in metformin-treated AGS cells. The findings demonstrated that metformin induced AMPK-mediated apoptosis, making it appealing for development as a novel anticancer drug for the treating gastric cancer.

Signaling through non-membrane nuclear phosphoinositide binding proteins in human health and disease

Phosphoinositide membrane signaling is critical for normal physiology, playing well-known roles in diverse human pathologies. The basic mechanisms governing phosphoinositide signaling within the nucleus, however, have remained deeply enigmatic owing to their presence outside the nuclear membranes. Over 40% of nuclear phosphoinositides can exist in this non-membrane state, held soluble in the nucleoplasm by nuclear proteins that remain largely unidentified. Recently, two nuclear proteins responsible for solubilizing phosphoinositides were identified, steroidogenic factor-1 (SF-1; NR5A1) and liver receptor homolog-1 (LRH-1; NR5A2), along with two enzymes that directly remodel these phosphoinositide/protein complexes, phosphatase and tensin homolog (PTEN; MMAC) and inositol polyphosphate multikinase (IPMK; ipk2). These new footholds now permit the assignment of physiological functions for nuclear phosphoinositides in human diseases, such as endometriosis, nonalcoholic fatty liver disease/steatohepatitis, glioblastoma, and hepatocellular carcinoma. The unique nature of nuclear phosphoinositide signaling affords extraordinary clinical opportunities for new biomarkers, diagnostics, and therapeutics. Thus, phosphoinositide biology within the nucleus may represent the next generation of low-hanging fruit for new drugs, not unlike what has occurred for membrane phosphatidylinositol 3-kinase drug development. This review connects recent basic science discoveries in nuclear phosphoinositide signaling to clinical pathologies, with the hope of inspiring development of new therapies.

Insufficient radiofrequency ablation promotes proliferation of residual hepatocellular carcinoma via autophagy

Radiofrequency ablation (RFA) is considered to be a potentially curative therapy for hepatocellular carcinoma (HCC). However, insufficient RFA (IRFA) can promote rapid progression of the residual tumor. The mechanisms underlying IRFA-induced tumor promotion remain poorly understood. In the present study, we have established a subcutaneous xenograft mouse model and monitored the location and extent of IRFA by dual monitoring with ultrasonography and a thermal imager. For the first time, we provide evidence of the activation of autophagic pathways in mice exposed to IRFA. We show that autophagy plays an important role in relapse and proliferation after IRFA and that hydroxychloroquine (HCQ) can suppress these effects. Our findings indicate that autophagy is involved in experimental IRFA and that inhibition of autophagy may be a novel approach in the treatment of local recurrences of HCC after IRFA in the clinic.