Targeting the PI3K/Akt/mTOR Pathway in Hepatocellular Carcinoma

Targeting EGFR/PI3K/AKT/mTOR Signaling in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) poses a significant global health concern, with its incidence steadily increasing. The development of HCC is a multifaceted, multi-step process involving alterations in various signaling cascades. In recent years, significant progress has been made in understanding the molecular signaling pathways that play central roles in hepatocarcinogenesis. In particular, the EGFR/PI3K/AKT/mTOR signaling pathway in HCC has garnered renewed attention from both basic and clinical researchers. Preclinical studies in vitro and in vivo have shown the effectiveness of targeting the key components of this signaling pathway in human HCC cells. Thus, targeting these signaling pathways with small molecule inhibitors holds promise as a potential therapeutic option for patients with HCC. In this review, we explore recent advancements in understanding the role of the EGFR/PI3K/AKT/mTOR signaling pathway in HCC and assess the effectiveness of targeting this signaling cascade as a potential strategy for HCC therapy based on preclinical studies.

Advances in radiotherapy and immunity in hepatocellular carcinoma

Primary liver cancer is one of the most common malignant tumours worldwide; it caused approximately 830,000 deaths in 2020. Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for over 80% of all cases. Various methods, including surgery, chemotherapy, radiotherapy, and radiofrequency ablation, have been widely used in the treatment of HCC. With the advancement of technology, radiotherapy has become increasingly important in the comprehensive treatment of HCC. However, due to the insufficient sensitivity of tumour cells to radiation, there are still multiple limitation in clinical application of radiotherapy. In recent years, the role of immunotherapy in cancer has been increasingly revealed, and more researchers have turned their attention to the combined application of immunotherapy and radiotherapy in the hope of achieving better treatment outcomes. This article reviews the progress on radiation therapy in HCC and the current status of its combined application with immunotherapy, and discusses the prospects and value of radioimmunotherapy in HCC.

Effects of LAIR-1 on hepatocellular carcinoma cell proliferation and invasion via PI3K-AKT-mTOR pathway regulation

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the common malignant tumors. Although surgical resection is the best treatment for HCC, many patients with HCC are found to have metastases at the time of initial diagnosis and lose the opportunity for radical treatment. Therefore, the study of the invasion and metastasis of HCC has always been the focus of HCC research. This study aimed to assess the influence of LAIR-1 on HCC cell proliferation and invasion and the relevant mechanisms involved in this process.

METHODS

Immunocytochemical staining assay, quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting (WB) were used to detect the expression of LAIR-1mRNA and protein in healthy human hepatocyte LO2 and the HCC cell lines HepG2, Bel-7402, MHCC97-H, and Huh-7. Then, we evaluated the cell viability, colony formation, and invasion of MHCC97-H and Huh-7 cells in each group by silencing or overexpressing LAIR-1 expression in MHCC97-H and Huh-7 cells, respectively. WB was used to detect the expression levels of PI3K-AKT-mTOR pathway related proteins.

RESULTS

Our findings showed that LAIR-1 can inhibit cell viability, colony formation and invasion in vitro. Meanwhile, LAIR-1 significantly downregulated the expression of PI3K, p-AKT and p-mTOR, which were abolished by the PI3K inhibitor, LY294002.

CONCLUSIONS

Our study revealed that LAIR-1 inhibited cell proliferation and invasion, probably via suppressing the PI3K-AKT-mTOR pathway.

TANGO1 interacts with NRTN to promote hepatocellular carcinoma progression by regulating the PI3K/AKT/mTOR signaling pathway

Transport and Golgi organization 1 (TANGO1) also known as MIA3, belongs to the melanoma inhibitory activity gene (MIA) family together with MIA, MIA2 and OTOR; these members play different roles in different tumors, but the mechanism underlying TANGO1s effect on hepatocellular carcinoma (HCC) is unclear. Our study confirmed that TANGO1 is a promoter of HCC, In HCC cells, TANGO1 can promote proliferation, inhibit apoptosis, promote EMT. These changes were reversed after TANGO1 inhibition. We explored the molecular mechanism of TANGO1 and HCC and found that the promoting effect of TANGO1 on HCC related to neurturin (NRTN) and the PI3K/AKT/mTOR signaling pathway based on RNA-seq results. NRTN is not only related to neuronal growth, differentiation and maintenance but is also involved in a variety of tumorigenic processes, and PI3K/AKT/mTOR signaling pathway has been shown to be involved in HCC progression. We verified that TANGO1 interacts with NRTN in HCC cells using endogenous Co-IP and confocal localization, and both promote HCC progression by activating the PI3K/AKT/mTOR signaling pathway. Our results reveal the mechanism by which TANGO1 promotes HCC progression, suggesting that the TANGO1/NRTN axis may be a potential therapeutic target for HCC worthy of further investigation.

The role of microRNAs in the different phases of liver regeneration

INTRODUCTION

Since the first discovery of microRNAs (miRs) extensive evidence reveals their indispensable role in different patho-physiological processes. They are recognized as critical regulators of hepatic regeneration, as they modulate multiple complex signaling pathways affecting liver regeneration. MiR-related translational suppression and degradation of target mRNAs and proteins are not limited to one specific gene, but act on multiple targets.

AREAS COVERED

In this review, we are going to explore the role of miRs in the context of liver regeneration and discuss the regulatory effects attributed to specific miRs. Moreover, specific pathways crucial for liver regeneration will be discussed, with a particular emphasis on the involvement of miRs within the respective signaling cascades.

EXPERT OPINION

The considerable amount of studies exploring miR functions in a variety of diseases paved the way for the development of miR-directed therapeutics. Clinical implementation has already shown promising results, but additional research is warranted to assure safe and efficient delivery. Nevertheless, given the broad functional properties of miRs and their critical involvement during hepatic regeneration, they represent an attractive treatment target to promote liver recovery after hepatic resection.

Hydrogen sulfide suppresses H2O2-induced proliferation and migration of HepG2 cells through Wnt/β-catenin signaling pathway

Both H₂S and H₂O₂ affect many cellular events, such as cell differentiation, cell proliferation and cell death. However, there is some controversy about the roles of H₂S and H₂O_2, since the detailed mechanisms they are involved remain unclear. In this study, low concentration of H₂O₂ (40 μM) increased the viability of hepatocellular carcinoma cells HepG2, while both H₂S and high concentration of H₂O₂ decreased the cell viability in a dose-dependent manner. Wound healing assay indicated that 40 μM H₂O₂ promoted migration of HepG2 cells, which was suppressed by exogenous H₂S. Further analysis revealed that administration of exogenous H₂S and H₂O₂ changed the redox status of Wnt3a in HepG2 cells. Altered expression of proteins including Cyclin D1, TCF-4, and MMP7, which are downstream of the Wnt3a/β-catenin signaling pathway, were found after treatment with exogenous H₂S and H₂O₂. Compared with H₂S, low concentration of H₂O₂ showed opposite effects on these protein expression levels in HepG2 cells. These results suggest that H₂S suppressed H₂O₂-induced proliferation and migration of HepG2 through regulating Wnt3a/β-catenin signaling pathway.

Ring finger protein 12 activates AKT signalling to promote the progression of liver cancer by interacting with EGFR

Liver cancer is one of the most common solid tumours, and ranks as the third leading cause of cancer-associated mortality around the world. This study has linked RNF12 to the pathogenesis of liver cancer. Based on the analysis of patient samples and database data, high RNF12 expression was found in liver cancer, in correlation with worse clinicopathological features and a poor prognosis. Meantime, RNF12 could promote the progression of liver cancer in vitro and in vivo. Mechanistically, RNF12 could interact with EGFR and decrease the internalization of EGFR to activate EGF/EGFR signalling. In addition, PI3K-AKT signalling takes part in the regulation of liver cancer cell proliferation and migration of RNF12. And AKT inhibitor MK2206 could reverse RNF12-mediated cellular proliferation and migration in liver cancer. The possibility of the physical interaction between RNF12 and EGFR might lay a foundation to develop intervention strategies for liver cancer prevention and therapy.

Role of lncRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the deadliest cancer in human malignancies. It is the most common and severe type of primary liver cancer. However, the molecular mechanisms underlying HCC pathogenesis remain poorly understood. Long non-coding RNAs (lncRNAs), a new kind of RNA and epigenetic factors, play a crucial role in tumorigenesis and the progression of HCC. LncRNAs are capable of promoting the autophagy, proliferation, and migration of tumor cells by targeting and modulating the expression of downstream genes in signaling pathways related to cancer; these transcripts modify the activity and expression of various tumor suppressors and oncogenes. LncRNAs could act as biomarkers for treatment approaches such as immunotherapy, chemotherapy, and surgery to effectively treat HCC patients. Improved knowledge regarding the aetiology of HCC may result from an advanced understanding of lncRNAs. Enhanced oxidative stress in the mitochondrial and Endoplasmic reticulum leads to the activation of unfolded protein response pathway that plays a crucial role in the pathophysiology of hepatocellular carcinoma. The mutual regulation between LncRNAs and Endoplasmic reticulum (ER) stress in cancer and simultaneous activation of the unfolded protein response (UPR) pathway determines the fate of tumor cells in HCC. Mitochondria-associated lncRNAs work as essential components of several gene regulatory networks; abnormal regulation of mitochondria-associated lncRNAs may lead to oncogenesis, which provides further insight into the understanding of tumorigenesis and therapeutic strategies.

Design, synthesis, and biological evaluation of 1-styrenyl isoquinoline derivatives for anti-hepatocellular carcinoma activity and effect on mitochondria

In this study, 18 derivatives of 1-styrene-isoquinoline were designed and synthesized from resveratrol and isoquinoline. The IC₅₀ of compound 1c against Huh7 and SK-Hep-1 cells were 2.52 μM and 4.20 μM, respectively. Mice were treated with 650 mg/kg compound 1c, and the survival status of mice was good. Further studies showed that compound 1c could inhibit cell proliferation by arresting the cell cycle in the G2/M phase, induce cell apoptosis, and inhibit cell migration and invasion by regulating epithelial-mesenchymal transition (EMT). It is worth noting that numbers of studies have pointed that resveratrol can trigger mitochondrial apoptosis to induce apoptosis of cancer cells. Therefore, we investigated the mechanism of compound 1c induced apoptosis of Huh7 and SK-Hep-1 cells. The results indicated that compound 1c could regulate the expression of proteins which are related to mitochondrial apoptosis pathway and inhibit the phosphorylation of PI3K/Akt/mTOR signaling pathway. In addition, compound 1c could inhibit the growth of Huh7-xenografts, and perform a tumor inhibitory rate of 41.44% when administered 30 mg/kg once a day. This work provides a potential anti-hepatocellular carcinoma compound that warrants further investigation.

Natural products in digestive tract tumors metabolism: Functional and application prospects

Digestive tract diseases are presently the hotspot of clinical diagnosis and treatment, and the incidence of digestive tract tumor is increasing annually. Surgery remains the main therapeutic schedule for digestive tract tumor. Though benefits were brought by neoadjuvant chemotherapy, a part of patients lose the chance of surgery because of late detection or inappropriate intervention. Therefore, the treatment of inoperable patients has become an urgent need. At the same time, tumor metabolism is an extremely complex and diverse process. Natural products are confirmed effective to inhibit the development of tumors in vitro and in vitro. There are many kinds of natural products and their functions remain not clear. However, some natural products such as polyphenols have been proven to have definite anti-cancer effects, and some terpenoids have definite anti-inflammatory, anti-ulcer, anti-tumor, and other effects. Therefore, the anti-tumor characteristics of natural products should arouse our high attention. Although there are many obstacles to study the activities of natural products in tumor, including the difficulty in detection or distinguishing each component due to their low levels in tumor tissue, etc., the emergence of highly sensitive and locatable spatial metabolomics make the research and application of natural products a big step forward. In this review, natural products such as phenols, terpenoids and biotinoids were summarized to further discuss the development and therapeutic properties of natural metabolites on digestive tract tumors.

Regulatory effect of orexin system on various diseases through mTOR signaling pathway

Orexin (OX)A and OXB are a pair of neuropeptides secreted by orexin-producing neurons in the lateral hypothalamus. The orexin system can regulate many physiological processes through these two receptor pathways, such as feeding behavior, sleep/wake state, energy homeostasis, reward, and the coordination of emotion. Mammalian target of rapamycin (mTOR) can coordinate upstream signals with downstream effectors, thereby regulating fundamental cellular processes and also plays an essential role in the signaling network downstream of the orexin system. In turn, the orexin system can activate mTOR. Here, we review the association of the orexin system with the mTOR signaling pathway mainly by discussing that drugs in various diseases exert their effects on the orexin system, indirectly affecting the mTOR signaling pathway.

Systemic treatment for unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is most commonly found in the context of liver cirrhosis and, in rare cases, in a healthy liver. Its prevalence has risen in recent years, particularly in Western nations, due to the increasing frequency of non-alcoholic fatty liver disease. Advanced HCC has a poor prognosis. For many years, the only proven therapy for unresectable HCC (uHCC) was sorafenib, a tyrosine kinase inhibitor. Recently, the synergistic effect of an immune checkpoint inhibitor, atezolizumab, and bevacizumab outperformed sorafenib alone in terms of survival, making it the recommended first-line therapy. Other multikinase inhibitors, lenvatinib and regorafenib, were also recommended as first and second-line drugs, respectively. Intermediate-stage HCC patients with retained liver function, particularly uHCC without extrahepatic metastasis, may benefit from trans-arterial chemoembolization. The current problem in uHCC is selecting a patient for the best treatment while considering the preexisting liver condition and liver function. Indeed, all study patients had a Child-Pugh class A, and the best therapy for other individuals is unknown. Additionally, in the absence of a medical contraindication, atezolizumab could be combined with bevacizumab for uHCC systemic therapy. Several studies are now underway to evaluate immune checkpoint inhibitors in combination with anti-angiogenic drugs, and the first findings are encouraging. The paradigm of uHCC therapy is changing dramatically, and many obstacles remain for optimum patient management in the near future. The purpose of this commentary review was to give an insight into current systemic treatment options for patients with uHCC who are not candidates for surgery to cure the disease.

Systemic treatment for unresectable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is most commonly found in the context of liver cirrhosis and, in rare cases, in a healthy liver. Its prevalence has risen in recent years, particularly in Western nations, due to the increasing frequency of non-alcoholic fatty liver disease. Advanced HCC has a poor prognosis. For many years, the only proven therapy for unresectable HCC (uHCC) was sorafenib, a tyrosine kinase inhibitor. Recently, the synergistic effect of an immune checkpoint inhibitor, atezolizumab, and bevacizumab outperformed sorafenib alone in terms of survival, making it the recommended first-line therapy. Other multikinase inhibitors, lenvatinib and regorafenib, were also recommended as first and second-line drugs, respectively. Intermediate-stage HCC patients with retained liver function, particularly uHCC without extrahepatic metastasis, may benefit from trans-arterial chemoembolization. The current problem in uHCC is selecting a patient for the best treatment while considering the preexisting liver condition and liver function. Indeed, all study patients had a Child-Pugh class A, and the best therapy for other individuals is unknown. Additionally, in the absence of a medical contraindication, atezolizumab could be combined with bevacizumab for uHCC systemic therapy. Several studies are now underway to evaluate immune checkpoint inhibitors in combination with anti-angiogenic drugs, and the first findings are encouraging. The paradigm of uHCC therapy is changing dramatically, and many obstacles remain for optimum patient management in the near future. The purpose of this commentary review was to give an insight into current systemic treatment options for patients with uHCC who are not candidates for surgery to cure the disease.

A Selective Androgen Receptor Modulator, S4, Displays Robust Anti-cancer Activity on Hepatocellular Cancer Cells by Negatively Regulating PI3K/AKT/mTOR Signaling Pathway

Hepatocellular carcinoma (HCC) is a major global health problem that often correlates with poor prognosis. Due to the insufficient therapy options with limited benefits, it is crucial to identify new therapeutic approaches to overcome HCC. One of the vital signaling pathways in organ homeostasis and male sexual development is Androgen Receptor (AR) signaling. Its activity affects several genes that contribute to cancer characteristics and have essential roles in cell cycle progression, proliferation, angiogenesis, and metastasis. AR signaling has been shown to be misregulated in many cancers, including HCC, suggesting that it might contribute to hepatocarcinogenesis. Targeting AR signaling using anti-androgens, AR inhibitors, or AR-degrading molecules is a powerful and promising strategy to defeat HCC. In this study, AR signaling was targeted by a novel Selective Androgen Receptor Modulator (SARM), S4, in HCC cells to evaluate its potential anti-cancer effect. To date, S4 activity in cancer has not been demonstrated, and our data unrevealed that S4 significantly impaired HCC growth, migration, proliferation, and induced apoptosis through inhibiting PI3K/AKT/mTOR signaling. Since PI3K/AKT/mTOR signaling is frequently activated in HCC and contributes to its aggressiveness and poor prognosis, its negative regulation by the downregulation of critical components via S4 was a prominent finding. Further studies are necessary to investigate the S4 action mechanism and anti-tumorigenic capacity in in-vivo.

Antioxidant and anti-inflammatory agents in chronic liver diseases: Molecular mechanisms and therapy

Chronic liver disease (CLD) is a continuous process that causes a reduction of liver function lasting more than six months. CLD includes alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), chronic viral infection, and autoimmune hepatitis, which can lead to liver fibrosis, cirrhosis, and cancer. Liver inflammation and oxidative stress are commonly associated with the development and progression of CLD. Molecular signaling pathways such as AMP-activated protein kinase (AMPK), C-Jun N-terminal kinase, and peroxisome proliferator-activated receptors (PPARs) are implicated in the pathogenesis of CLD. Therefore, antioxidant and anti-inflammatory agents from natural products are new potent therapies for ALD, NAFLD, and hepatocellular carcinoma (HCC). In this review, we summarize some powerful products that can be potential applied in all the stages of CLD, from ALD/NAFLD to HCC. The selected agents such as β-sitosterol, curcumin, genistein, and silymarin can regulate the activation of several important molecules, including AMPK, Farnesoid X receptor, nuclear factor erythroid 2-related factor-2, PPARs, phosphatidylinositol-3-kinase, and lysyl oxidase-like proteins. In addition, clinical trials are undergoing to evaluate their efficacy and safety.

Anti-hepatitis B virus activity of lithospermic acid, a polyphenol from Salvia miltiorrhiza, in vitro and in vivo by autophagy regulation

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza (the roots of S. miltiorrhiza Bunge, Danshen in Chinese), a traditional Chinese medicine, has been clinically used to prevent and treat various diseases, such as cardiovascular and cerebrovascular diseases, diabetes, and hepatitis B, in China and some other Asian countries. Lithospermic acid (LA), a polyphenol derived from S. miltiorrhiza, has been reported to exhibit multiple pharmacological properties, such as anti-inflammatory, anti-HIV, and anti-carbon tetrachloride-induced liver injury activities. However, little is known about the anti-hepatitis B virus (HBV) activity of LA.

AIM OF THE STUDY

The study was projected to investigate the anti-HBV activity of LA in vitro (HepG2.2.15 and pHBV1.3-transfected HepG2 cells) and in vivo (pAAV-HBV1.2 hydrodynamic injection [HBV-HDI] mice) and explore the potential mechanism as well.

MATERIALS AND METHODS

Hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) contents were detected by ELISA kits. HBV DNA and hepatitis B core antigen (HBcAg) levels were evaluated by quantitative real-time polymerase chain reaction and immunohistochemistry assay, respectively. The proteins in autophagy process, lysosomal acidic function, and autophagy-related signaling pathways were examined by Western blot. Transmission electron microscopy was used to observe the number of autophagosomes and autolysosomes. Confocal microscopy was applied to analyze the autophagic flux and lysosomal acidification, using mCherry-enhanced green fluorescent protein (EGFP)-microtubule-associated protein light chain (LC)3 and lysosomal probes, respectively.

RESULTS

LA exhibited anti-HBV activity by inhibiting HBV DNA replication in HepG2.2.15 and pHBV-transfected HepG2 cells in dose- and time-dependent manners and hampering HBsAg and HBeAg levels in HepG2.2.15 cells to a certain extent. LA reduced HBV DNA, HBsAg/HBeAg, and HBcAg levels in the serum/liver tissues of HBV-HDI C57BL/6 mice during the 3-week treatment and suppressed the withdrawal rebound of HBV DNA and HBsAg in the mice serum. LA increased LC3-II protein expression and the number of autolysosomes/autophagosomes and promoted the degradation of sequestosome 1(p62) protein in vitro and in vivo. LA enhanced the co-localization of LC3 protein with autolysosomes, further confirming the ability of LA to induce a complete autophagy. Knockdown of autophagy-related gene (Atg) 7 or 5 in vitro and administration of 3-methyladenine (an autophagic inhibitor) in vivo disabled the inhibitory efficacy of LA on HBV DNA replication, suggesting that the anti-HBV efficacy of LA depended on its ability of inducing autophagy. LA could enhance lysosomal acidification and improve the function of lysosomes by promoting the protein expression of lysosomal-associated membrane protein (LAMP)-1, LAMP-2, and mature cathepsin D, which may contribute to the autophagic induction of LA. LA inhibited the activation of AKT and mammalian target of rapamycin (mTOR) induced by HBV, which was reversed by IGF-1 (an agonist of the PI3K/AKT/mTOR signaling pathway), indicating that LA elicited autophagy through hampering the PI3K/AKT/mTOR signaling pathway.

CONCLUSION

We revealed the anti-HBV activity and mechanism of LA in vitro and in vivo. This study facilitates a new understanding of the anti-HBV potent components of S. miltiorrhiza and sheds light on LA for further development as an active constituent or candidate used in the therapy against HBV infection.

The mechanism of flavonoids from Cyclocarya paliurus on inhibiting liver cancer based on in vitro experiments and network pharmacology

Introduction: Cyclocarya paliurus (Batal.) Iljinsk., a subtropical tree belonging to the family Juglandaceae, is rich in polysaccharides, flavonoids, and terpenoids. It has important pharmacological effects such as lowering blood lipids, blood sugar, and blood pressure. However, little has been discerned regarding anti tumor effects and their potential mechanisms. Method: In vitro cell culture experiments were used to test the effect of C. paliurus total flavonoids (CTFs) extract on apoptosis mechanisms in HepG2 cells. Network pharmacology was applied to further explore the effects of CTFs on liver cancer as well as the mechanisms through which these effects might be achieved. Both 3 hydroxyflavone and luteolin were randomly selected to verify the effect on inducing apoptosis and inhibiting the proliferation of HepG2 cells. Results and Discussion: Network pharmacological analysis was applied to these 62 compounds and their targets, and 13 flavonoids were further screened for their potential anti liver cancer activity. These 13 flavonoids included: tangeretin, baicalein, 7,3'-dihydroxyflavone, velutin, 3-hydroxyflavone, chrysin, kumatakenin, tricin, luteolin, chrysoeriol, apigenin, pinocembrin, and butin. Together, these flavonoids were predicted to interact with AKT1, MAPK3, PIK3CA, EGFR, MAP2K1, SRC, IGF1R, IKBKB, MET, and MAPK14. It was predicted that the inhibitory effect on hepatocellular carcinoma would be accomplished by regulation of core proteins relating to such KEGG pathways as cancer, PI3K-Akt, proteoglycans in cancer, microRNAs in cancer, and endocrine resistance via core target proteins. Both 3-hydroxyflavone and luteolin were demonstrated to induce apoptosis and inhibit the proliferation of HepG2 cells. Our study provides scientific evidence supporting the use of CTFs for the treatment of liver cancer.

Circular RNA ITCH increases sorafenib-sensitivity in hepatocellular carcinoma via sequestering miR-20b-5p and modulating the downstream PTEN-PI3K/Akt pathway

BACKGROUNDS

Sorafenib-resistance leads to poor prognosis and high mortality in advanced hepatocellular carcinoma (HCC), and this study aims to investigate the functional role of a circular RNA ITCH (circITCH) in regulating the sorafenib-resistance of HCC and its underlying mechanisms.

METHODS

The expression of circITCH in HCC tissues and cell lines were detected by performing quantitative real-time polymerase chain reaction. Sorafenib-resistant HCC cells were transfected with PLCDH-circITCH to upregulate circITCH and intervened with sorafenib, and MTT assay, flow cytometry and transwell assay were used to test the cell viability, apoptosis and migration ability, respectively. The downstream target of circITCH were explored by using bioinformatic analysis, dual luciferase reporter system and Western blot.

RESULTS

CircITCH was significantly down-regulated in HCC tissues and cell lines, compared with their normal counterparts. Especially, in contrast with the sorafenib-sensitive HCC cells, continuous sorafenib treatment decreased the expression levels of circITCH in the sorafenib-resistant HCC cells. Overexpression of circITCH increased sorafenib-sensitivity, promoted cell apoptosis and reduced cell migration abilities in the sorafenib-resistant HCC cells. Mechanically, circITCH elevated PTEN expression to inactivate the PI3K/Akt signals through negatively regulating miR-20b-5p in HCC, and upregulating miR-20b-5p or inhibiting PTEN abolished the enhancing effect of circITCH overexpression on sorafenib-induced cytotoxicity in sorafenib-resistant HCC cells.

CONCLUSION

Taken together, this study proves that circITCH enhances sorafenib-sensitivity in sorafenib-resistant HCC cells via regulating the miR-20b-5p/PTEN/PI3K/Akt signaling cascade, which highlights the potential value of circITCH as a target for enhancing the sorafenib-sensitivity in HCC.

PI3K δ inhibitor PI-3065 induces apoptosis in hepatocellular carcinoma cells by targeting survivin

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide, and its clinical treatment remains challenging. The development of new treatment regimens is important for effective HCC treatment. Phosphoinositide 3-kinase (PI3K) is a lipid kinase that plays an important role in cell growth and metabolism and is overexpressed in nearly 50% of patients with HCC. Studies have shown that PI-3065, a small-molecule inhibitor of phosphatidylinositol 3-kinase delta, significantly inhibits solid breast cancer. However, its antitumor effects against HCC and the underlying mechanisms remain unclear. In the present study, we found that PI-3065 dose- and time-dependently reduced HCC cell viability and induced apoptosis while posing no obvious apoptotic toxicity in normal liver cells. Further mechanistic analysis showed that PI-3065 induced apoptosis mainly by inhibiting survivin protein expression, decreasing mitochondrial membrane potential, and promoting cytochrome C release. Simultaneously, PI-3065 markedly suppressed the colony formation, migration, and epithelial-mesenchymal transition abilities of HCC cells. Furthermore, transplantation of nude mice with HCC tumors showed that PI-3065 inhibits HCC tumor growth in vivo by targeting survivin. In summary, PI-3065 specifically inhibited survivin expression and exerted anti-HCC activity in vivo and in vitro, suggesting that it may serve as an effective antitumor drug for HCC treatment, which warrants further study.

Clinical Utility of Comprehensive Genomic Profiling in Patients with Unresectable Hepatocellular Carcinoma

The molecular mechanism of hepatocellular carcinoma (HCC) is partially demonstrated. Moreover, in the patients receiving multiple molecular-targeted therapies, the gene alternations are still unknown. Six molecular-targeted therapies of unresectable HCC (uHCC) and comprehensive genomic profiling (CGP) have been approved in clinical practice. Hence, the utility of CGP in patients with uHCC treated with multiple molecular-targeted agents is investigated. The data of the patients with uHCC who received CGP tests were collected, retrospectively, between February 2021 and May 2022. Gene alterations detected by foundation testing, excluding variants of unknown significance, were reported in all nine patients. The samples for CGP were derived from liver tumor biopsy (n = 2), surgical specimens of bone metastases (n = 2), and blood (n = 5). The median number of systemic therapies was four. Seven patients were candidates eligible for clinical trials. One patient with a high tumor mutation burden (TMB) could receive pembrolizumab after CGP. This study presented genomic alternations after receiving multiple molecular-targeted therapies. However, further investigation needs to be conducted to develop personalized therapies and invent newer agents for treating HCC.

Cellular and Molecular Biology of Cancer Stem Cells of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death globally. The cancer stem cells (CSCs) of HCC are responsible for tumor growth, invasion, metastasis, recurrence, chemoresistance, target therapy resistance and radioresistance. The reported main surface markers used to identify liver CSCs include epithelial cell adhesion/activating molecule (EpCAM), cluster differentiation 90 (CD90), CD44 and CD133. The main molecular signaling pathways include the Wnt/β-catenin, transforming growth factors-β (TGF-β), sonic hedgehog (SHH), PI3K/Akt/mTOR and Notch. Patients with EpCAM-positive alpha-fetoprotein (AFP)-positive HCC are usually young but have advanced tumor-node-metastasis (TNM) stages. CD90-positive HCCs are usually poorly differentiated with worse prognosis. Those with CD44-positive HCC cells develop early metastases. Those with CD133 expression have a higher recurrence rate and a shorter overall survival. The Wnt/β-catenin signaling pathway triggers angiogenesis, tumor infiltration and metastasis through the enhancement of angiogenic factors. All CD133+ liver CSCs, CD133+/EpCAM+ liver CSCs and CD44+ liver CSCs contribute to sorafenib resistance. SHH signaling could protect HCC cells against ionizing radiation in an autocrine manner. Reducing the CSC population of HCC is crucial for the improvement of the therapy of advanced HCC. However, targeting CSCs of HCC is still challenging.

Effect of Novel AKT Inhibitor Vevorisertib as Single Agent and in Combination with Sorafenib on Hepatocellular Carcinoma in a Cirrhotic Rat Model

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related mortality worldwide. The AKT pathway is often activated in HCC cases, and a longer exposure to tyrosine kinase inhibitors such as sorafenib may lead to over-activation of the AKT pathway, leading to HCC resistance. Here, we studied the efficacy of a new generation of allosteric AKT inhibitor, vevorisertib, alone or in combination with sorafenib. To identify specific adverse effects related to the background of cirrhosis, we used a diethylnitrosamine (DEN)-induced cirrhotic rat model. Vevorisertib was tested in vitro on Hep3B, HepG2, HuH7 and PLC/PRF cell lines. Rats were treated weekly with intra-peritoneal injections of DEN for 14 weeks to obtain cirrhosis with fully developed HCC. After that, rats were randomized into four groups (n = 7/group): control, sorafenib, vevorisertib and the combination of vevorisertib + sorafenib, and treated for 6 weeks. Tumor progression was followed by MRI. We demonstrated that the vevorisertib is a highly potent treatment, blocking the phosphorylation of AKT. The tumor progression in the rat liver was significantly reduced by treatment with vevorisertib + sorafenib (49.4%) compared to the control group (158.8%, p < 0.0001). Tumor size, tumor number and tumor cell proliferation were significantly reduced in both the vevorisertib group and vevorisertib + sorafenib groups compared to the control group. Sirius red staining showed an improvement in liver fibrosis by vevorisertib and the combination treatment. Moreover, vevorisertib + sorafenib treatment was associated with a normalization in the liver vasculature. Altogether, vevorisertib as a single agent and its combination with sorafenib exerted a strong suppression of tumor progression and improved liver fibrosis. Thus, results provide a rationale for testing vevorisertib in clinical settings and confirm the importance of targeting AKT in HCC.

Does IFITM3 link inflammation to tumorigenesis?

Uncontrolled chronic inflammation, in most cases due to excessive cytokine signaling through their receptors, is known to contribute to the development of tumorigenesis. Recently, it has been reported that the antiviral membrane protein interferon-induced transmembrane protein 3 (IFITM3), induced by interferon signaling as part of the inflammatory response after viral infection, contributes to the development of B-cell malignancy. The unexpected oncogenic signaling of IFITM3 upon malignant B cell activation elucidated the mechanism by which the uncontrolled expression of inflammatory proteins contributes to leukemogenesis. In this review, the potential effects of inflammatory cytokines on upregulation of IFITM3 and its contribution to tumorigenesis are discussed. [BMB Reports 2022; 55(12): 602-608].

Does IFITM3 link inflammation to tumorigenesis?

Uncontrolled chronic inflammation, in most cases due to excessive cytokine signaling through their receptors, is known to contribute to the development of tumorigenesis. Recently, it has been reported that the antiviral membrane protein interferon-induced transmembrane protein 3 (IFITM3), induced by interferon signaling as part of the inflammatory response after viral infection, contributes to the development of B-cell malignancy. The unexpected oncogenic signaling of IFITM3 upon malignant B cell activation elucidated the mechanism by which the uncontrolled expression of inflammatory proteins contributes to leukemogenesis. In this review, the potential effects of inflammatory cytokines on upregulation of IFITM3 and its contribution to tumorigenesis are discussed. [BMB Reports 2022; 55(12): 602-608].

HMGA1 As a Potential Prognostic and Therapeutic Biomarker in Breast Cancer

Background

High-mobility group AT-hook1 (HMGA1) protein plays an important role in various diseases. However, the contribution of HMGA1 in breast cancer remains to be tapped.

Methods

The expression of HMGA1 was analyzed in The Cancer Genome Atlas (TCGA) and TIMER database, and immunohistochemistry was performed in 39 breast cancer (BC) patients. The correlation between HMGA1 expression and prognosis was evaluated using Kaplan-Meier plotter (KM plotter) in patients with breast cancer. Then, cBioPortal and bc-GenExMiner were requisitioned to analyze the contribution of HMGA1 expression to clinical features. In order to reveal the function of HMGA1 in breast cancer cells, enrichment analysis was performed using the clusterProfiler R software package. Moreover, CCK8 assay, EdU assay, and Cell Cycle Assay were performed to assess the proliferation, and transwell assay was used to evaluate cell migration and invasion. Flow cytometry was used to explore the role of HMGA1 on cell apoptosis. After that, the effect of HMGA1 on signaling pathways in BC cells was detected by western blot.

Results

HMGA1 was highly expressed in a variety of tumors tissues, including BC. High HMGA1 expression was correlated with poor prognosis in BC patients. Meanwhile, HMGA1 expression was increased in molecular phenotypes with poor prognosis (ER-, PR-, and HER2+) and associated with high-grade group, lymph node metastasis, and NPI (Nottingham Prognostic Index). Further, function analysis revealed HMGA1 was enriched in DNA replication and cell cycle pathways in breast cancer. Moreover, knockdown of HMGA1 caused apoptosis, inhibited proliferation, migration, and invasion of MCF-7 and MDA-MB-231 cells, in which the oncogenic signaling pathway of PI3K/AKT/MMP9 played a critical role.

Conclusions

HMGA1 was important for breast cancer progression and was a critical prognostic indicator, prompting a potential therapeutic target of breast cancer.

Differential in vitro effects of targeted therapeutics in primary human liver cancer: importance for combined liver cancer

The incidence of primary liver tumors, hepatocellular carcinoma (HCC), intrahepatic cholangiocellular carcinoma (ICC), and combined HCC/ICC (cHCC/CC) is increasing. For ICC, targeted therapy exists only for a small subpopulation of patients, while for HCC, Sorafenib and Lenvatinib are in use. Diagnosis of cHCC/CC is a great challenge and its incidence is underestimated, bearing the risk of unintended non-treatment of ICC. Here, we investigated effects of targeted inhibitors on human ICC cell lines (HUH28, RBE, SSP25), in comparison to extrahepatic (E)CC lines (EGI1, CCC5, TFK1), and HCC/hepatoblastoma cell lines (HEP3B, HUH7, HEPG2). Cells were challenged with: AKT inhibitor MK-2206; multikinase inhibitors Sorafenib, Lenvatinib and Dasatinib; PI3-kinase inhibitors BKM-120, Wortmannin, LY294002, and CAL-101; and mTOR inhibitor Rapamycin. Dosage of the substances was based on the large number of published data of recent years. Proliferation was analyzed daily for four days. All cell lines were highly responsive to MK-2206. Thereby, MK-2206 reduced expression of phospho(p)-AKT in all ICC, ECC, and HCC lines, which mostly corresponded to reduction of p-mTOR, whereas p-ERK1/2 was upregulated in many cases. Lenvatinib showed inhibitory effects on the two HCC cell lines, but not on HEPG2, ICCs and ECCs. Sorafenib inhibited proliferation of all cells, except the ECC line CCC5. However, at reduced dosage, we observed increased cell numbers in some ICC experiments. Dasatinib was highly effective especially in ICC cell lines. Inhibitory effects were observed with all four PI3-kinase inhibitors. However, cell type-specific differences were also evident here. Rapamycin was most effective in the two HCC cell lines. Our studies show that the nine inhibitors differentially target ICC, ECC, and HCC/hepatoblastoma lines. Caution should be taken with Lenvatinib and Sorafenib administration in patients with cHCC/CC as the drugs may have no effects on, or might even stimulate, ICC.

Protein phosphatases regulate the liver microenvironment in the development of hepatocellular carcinoma

The liver is a complicated heterogeneous organ composed of different cells. Parenchymal cells called hepatocytes and various nonparenchymal cells, including immune cells and stromal cells, are distributed in liver lobules with hepatic architecture. They interact with each other to compose the liver microenvironment and determine its characteristics. Although the liver microenvironment maintains liver homeostasis and function under healthy conditions, it also shows proinflammatory and profibrogenic characteristics that can induce the progression of hepatitis and hepatic fibrosis, eventually changing to a protumoral microenvironment that contributes to the development of hepatocellular carcinoma (HCC). According to recent studies, phosphatases are involved in liver diseases and HCC development by regulating protein phosphorylation in intracellular signaling pathways and changing the activities and characteristics of liver cells. Therefore, this review aims to highlight the importance of protein phosphatases in HCC development and in the regulation of the cellular components in the liver microenvironment and to show their significance as therapeutic targets.

NAP1L5 targeting combined with MYH9 Inhibit HCC progression through PI3K/AKT/mTOR signaling pathway

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide. Nucleosome assembly protein 1-like 5 (NAP1L5) is a protein-coding gene that encodes a protein similar to nucleosome assembly protein 1 (NAP1). It is a histone chaperone that plays an important role in gene transcription in organisms. However, the role of NAP1L5 in the pathogenesis of hepatocellular carcinoma remains to be elucidated. In this study, low expression of NAP1L5 was found in hepatocellular carcinoma, and the downregulation of NAP1L5 was related to shorter survival and disease-free survival. In addition, its expression is also related to the tumor size and recurrence of hepatocellular carcinoma. The overexpression and knockdown of NAP1L5 by plasmid and siRNA showed that NAP1L5 inhibited the proliferation, migration and invasion and induced apoptosis of hepatoma cells. In vivo experiments confirmed that NAP1L5 can inhibit the growth and metastasis of hepatocellular carcinoma cells. In the mechanistic study, we found that NAP1L5 affects the occurrence and development of hepatocellular carcinoma by regulating MYH9 to inhibit the PI3K/AKT/mTOR signaling pathway. As a functional tumor suppressor, NAP1L5 is expressed at low levels in HCC. NAP1L5 inhibits the PI3K/AKT/mTOR signaling pathway in hepatocellular carcinoma by regulating MYH9. It may be a new potential target for liver cancer treatment.

Laminaria japonica Peptides Suppress Liver Cancer by Inducing Apoptosis: Possible Signaling Pathways and Mechanism

The anticancer properties of Laminaria japonica peptides (LJPs) have never been studied. Here, we extracted LJPs from fresh seaweed and explored their anti-liver cancer activity (in vivo and in vitro). LJPs were isolated/purified by HPLC-ESI-MS. HepG2 cell apoptosis and cell cycle were evaluated. MTT assays were used to examine the cytotoxicity of LJPs. Caspase activation of caspases 3 and 9, cleaved caspases 3 and 9, and cleaved PARP was examined by Western blotting. The PI3K/AKT pathway and the phosphorylation states of MAPKs (p38 and JNK) were examined. We found that the LJP-1 peptide had the most antiproliferative activity in H22 cells in vitro. LJP-1 blocked H22 cells in the G0/G1 phase, accompanied by inhibition of cyclin expression. LJP-1 induced apoptosis through caspase activation and regulation of the ASK1/MAPK pathway. Concurrent in vivo studies demonstrated that LJP-1 significantly inhibited tumor growth and induced tumor cell apoptosis/necrosis. In conclusion, LJPs, particularly LJP-1, exert strong inhibitory effects on liver cancer growth in vivo and in vitro. LJP-1 induces HCC cell apoptosis through the caspase-dependent pathway and G0/G1 arrest. LJP-1 induces caspase-dependent apoptosis, in part by inhibiting PI3K, MAPK signaling pathways, and cell cycle proteins. LJP-1 has the potential to be a novel candidate for human liver cancer therapeutics.

Exploring the potential targets of Sanshimao formula for hepatocellular carcinoma treatment by a method of network pharmacology combined with molecular biology

ETHNOPHARMACOLOGICAL RELEVANCE

The Sanshimao (SSM) formula is an effective prescription for hepatocellular carcinoma (HCC) therapy in the clinical setting. This prescription is made up of four herbals, Maorenshen, Shijianchuan, Shishangbai and Shidachuan, which are used for detoxification and removing blood stasis. However, its mechanism in the treatment of HCC remains ambiguous.

AIM OF THE STUDY

To explore the potential targets of SSM against HCC by network pharmacology analysis and verify the data using molecular biological methods.

MATERIALS AND METHODS

We screened active components and potential targets by data mining, constructed a network, and performed functional analysis and pathway enrichment to explore the therapeutic targets of SSM for HCC treatment. Then, the effects of SSM on HCC cells were studied to validate the data from network pharmacology analysis.

RESULTS

Eighty-eight common targets were obtained by mapping 932 HCC-related genes, and 325 targets corresponded to 11 active components of SSM. They were enriched in various biological processes, such as the response to inorganic substances, response to toxic substances and apoptotic signalling pathway, and multi-pathways involved pathways in cancer, EGFR tyrosine kinase inhibitor resistance, and AGE-RAGE signalling pathway in diabetic complications, as evaluated by the analysis of advanced functions and pathways. TP53, JUN, HSP90AA1, EGFR, AR and MAPK1 might be the core targets closely related to the effects of SSM on HCC according to PPI analysis. Treatment with SSM decreased cell viability and migration, promoted apoptosis and inhibited the EGFR/FAK/AKT signalling pathway.

CONCLUSION

This research preliminarily indicates that SSM treats HCC via multiple components and pathways. EGFR/FAK/AKT are promising therapeutic targets of SSM for HCC treatment. This provides objective evidence for further mechanistic research and the future development and clinical application of SSM in HCC patients.

Circular RNA circRASSF5 Functions as an Anti-Oncogenic Factor in Hepatocellular Carcinoma by Acting as a Competitive Endogenous RNA Through Sponging miR-331-3p

Objective

Recently, emerging studies have validated that circular RNAs participate in multiple biological progresses in various human malignant tumors, including hepatocellular carcinoma (HCC). However, until now, the elucidated mechanism of circular RNAs is only the tip of the iceberg. In this study, we firstly identify a novel circular RNA circRASSF5 (the only circular RNA derived from the RASSF5 gene), and attempt to investigate its biological function and underlying mechanism in HCC.

Methods

qRT-PCR, Western blotting and IHC were applied to detect the expression of related genes. CCK-8 assay, EdU staining, wound healing and transwell assays were used to investigate HCC proliferation, migration and invasion abilities. Animal model studies were included to investigate the function of circRASSF5 in HCC tumorigenesis and metastasis. RNA pull-down assay, luciferase reporter assay and FISH (fluorescence in situ hybridization) assay were performed to explore the potential biological mechanism underlying circRASSF5 function in HCC.

Results

CircRASSF5 is obviously downregulated in both HCC tissues and cell lines. Low level of circRASSF5 is negatively associated with larger tumor size, severe vascular invasion, more portal vein tumor embolus and unfavorable prognosis. Loss-of-function assay reveals that circRASSF5 remarkably impedes the growth and metastasis of HCC cells in vitro and in vivo. Mechanistically, circRASSF5 directly interacts with miR-331-3p as a sponge, and then enhances the expression of PH domain and leucine-rich repeat protein phosphatase (PHLPP), thus restraining the progression of HCC cells.

Conclusion

Altogether, we validate that circRASSF5 is a tumor suppressor in HCC, which competitively sponges with miR-331-3p and then enhances the tumor inhibitory effect of PHLPP, indicating the potential application value of circRASSF5 for HCC diagnosis and clinical treatment.

Leptin signaling and leptin resistance

With the prevalence of obesity and associated comorbidities, studies aimed at revealing mechanisms that regulate energy homeostasis have gained increasing interest. In 1994, the cloning of leptin was a milestone in metabolic research. As an adipocytokine, leptin governs food intake and energy homeostasis through leptin receptors (LepR) in the brain. The failure of increased leptin levels to suppress feeding and elevate energy expenditure is referred to as leptin resistance, which encompasses complex pathophysiological processes. Within the brain, LepR-expressing neurons are distributed in hypothalamus and other brain areas, and each population of the LepR-expressing neurons may mediate particular aspects of leptin effects. In LepR-expressing neurons, the binding of leptin to LepR initiates multiple signaling cascades including janus kinase (JAK)-signal transducers and activators of transcription (STAT) phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT), extracellular regulated protein kinase (ERK), and AMP-activated protein kinase (AMPK) signaling, etc., mediating leptin actions. These findings place leptin at the intersection of metabolic and neuroendocrine regulations, and render leptin a key target for treating obesity and associated comorbidities. This review highlights the main discoveries that shaped the field of leptin for better understanding of the mechanism governing metabolic homeostasis, and guides the development of safe and effective interventions to treat obesity and associated diseases.

DHW-208, A Novel Phosphatidylinositol 3-Kinase (PI3K) Inhibitor, Has Anti-Hepatocellular Carcinoma Activity Through Promoting Apoptosis and Inhibiting Angiogenesis

Hepatocellular carcinoma (HCC) is one of the most common tumors worldwide with high prevalence and lethality. Due to insidious onset and lack of early symptoms, most HCC patients are diagnosed at advanced stages without adequate methods but systemic therapies. PI3K/AKT/mTOR signaling pathway plays a crucial role in the progression and development of HCC. Aberrant activation of PI3K/AKT/mTOR pathway is involved in diverse biological processes, including cell proliferation, apoptosis, migration, invasion and angiogenesis. Therefore, the development of PI3K-targeted inhibitors is of great significance for the treatment of HCC. DHW-208 is a novel 4-aminoquinazoline derivative pan-PI3K inhibitor. This study aimed to assess the therapeutic efficacy of DHW-208 in HCC and investigate its underlying mechanism. DHW-208 could inhibit the proliferation, migration, invasion and angiogenesis of HCC through the PI3K/AKT/mTOR signaling pathway in vitro. Consistent with the in vitro results, in vivo studies demonstrated that DHW-208 elicits an antitumor effect by inhibiting the PI3K/AKT/mTOR-signaling pathway with a high degree of safety in HCC. Therefore, DHW-208 is a candidate compound to be developed as a small molecule PI3K inhibitor for the treatment of HCC, and our study provides a certain theoretical basis for the treatment of HCC and the development of PI3K inhibitors.

LINC00958: A promising long non-coding RNA related to cancer

Long non-coding RNAs (lncRNAs), a class of RNA transcripts longer than 200 nucleotides, do not encode proteins; however, they encode small peptides and micropeptides that act as bioactive peptides with notable effects in regulating the progression of malignant tumors, such as lung and colorectal cancers, and affecting patient prognosis. lncRNAs are important intracellular regulators, particularly in tumorigenesis and tumor progression. Long intergenic non-protein coding RNA958 (LINC00958), which has received increasing attention in recent years, is highly expressed in various malignancies, including head and neck squamous cell carcinoma (HNSC), non-small-cell lung cancer (NSCLC), gastric cancer, hepatocellular carcinoma (HCC), colorectal cancer, bladder cancer, and breast cancer. Here, we reviewed the recent studies on LINC00958 as well as its closely related clinical features and functional regulation in cancers. We systematically expounded the molecular mechanisms underlying the biological functions of LINC00958 in inhibiting cell apoptosis and enhancing the chemoradiotherapy resistance of tumor cells. The upregulation of LINC00958 enhances the resistance of tumor cells to radiotherapy and chemotherapy and induces lymphangiogenesis. Moreover, it is involved in tumor glycolytic metabolism, which plays a crucial role in facilitating the proliferation, invasion, and migration of tumor cells. Additionally, analysis of various studies revealed that LINC00958 acts as an endogenous competitive RNA (ceRNA) and regulates the malignant behavior of tumor cells through the miRNA-mRNA axis. Collectively, the use of LINC00958 as a novel biomarker and therapeutic target for the clinical diagnosis and treatment of different cancers has bright prospects in the future.

The Emerging Role of Branched-Chain Amino Acids in Liver Diseases

Chronic liver diseases pose a substantial health burden worldwide, with approximately two million deaths each year. Branched-chain amino acids (BCAAs)-valine, leucine, and isoleucine-are a group of essential amino acids that are essential for human health. Despite the necessity of a dietary intake of BCAA, emerging data indicate the undeniable correlation between elevated circulating BCAA levels and chronic liver diseases, including non-alcoholic fatty liver diseases (NAFLD), cirrhosis, and hepatocellular carcinoma (HCC). Moreover, circulatory BCAAs were positively associated with a higher cholesterol level, liver fat content, and insulin resistance (IR). However, BCAA supplementation was found to provide positive outcomes in cirrhosis and HCC patients. This review will attempt to address the contradictory claims found in the literature, with a special focus on BCAAs' distribution, key signaling pathways, and the modulation of gut microbiota. This should provide a better understanding of BCAAs' possible contribution to liver health.

Circular RNAs in hepatocellular carcinoma: Recent advances

Circular RNAs (circRNAs) have covalently closed loop structures at both ends, exhibiting characteristics dissimilar to those of linear RNAs. Emerging evidence suggests that aberrantly expressed circRNAs play crucial roles in hepatocellular carcinoma (HCC) by affecting the proliferation, apoptosis and invasive capacity of HCC cells. Certain circRNAs may be used as biomarkers to diagnose and predict the prognosis of HCC. Therefore, circRNAs are expected to become novel biomarkers and therapeutic targets for HCC. Herein, we briefly review the characteristics and biological functions of circRNAs, focusing on their roles in HCC to provide new insights for the early diagnosis and targeted therapy of HCC.

The potential role of FNDC5/irisin in various liver diseases: awakening the sleeping beauties

Fibronectin type III domain-containing protein 5 (FNDC5) is a transmembrane protein and the precursor of irisin, which serves as a systemic exerkine/myokine with multiple origins. Since its discovery in 2012, this hormone-like polypeptide has rapidly evolved to a component significantly involved in a gamut of metabolic dysregulations and various liver diseases. After a decade of extensive investigation on FNDC5/irisin, we are still surrounded by lots of open questions regarding its diagnostic and therapeutic values. In this review, we first concentrated on the structure-function relationship of FNDC5/irisin. Next, we comprehensively summarised the current knowledge and research findings regarding pathogenic roles/therapeutic applications of FNDC5/irisin in the context of non-alcoholic fatty liver disease, fibrosis, liver injury due to multiple detrimental insults, hepatic malignancy and intrahepatic cholestasis of pregnancy. Moreover, the prominent molecules involved in the underlying mechanisms and signalling pathways were highlighted. As a result, emerging evidence reveals FNDC5/irisin may act as a proxy for diagnosing liver disease pathology, a sensitive biomarker for assessing damage severity, a predisposing factor for surveilling illness progression and a treatment option with protective/preventive impact, all of which are highly dependent on disease grading and contextually pathological features.

Exosomes From Cancer-Associated Mesenchymal Stem Cells Transmit TMBIM6 to Promote the Malignant Behavior of Hepatocellular Carcinoma via Activating PI3K/AKT Pathway

Objective

Cancer-associated mesenchymal stem cells (MSCs) regulate the progression of cancers through exosome-delivered components, while few studies are conducted on hepatocellular carcinoma (HCC). This study aimed to evaluate the effect of exosomes from HCC-associated MSCs (HCC-MSCs) on HCC cellular functions and the potential regulatory mechanism.

Methods

HCC cells (Huh7 and PLC) were cultured normally or co-cultured with HCC-MSCs, HCC-MSCs plus GW4869, or HCC-MSC-derived exosomes; then mRNA sequencing and RT-qPCR validation were conducted. Subsequently, candidate genes were sorted out and modified in HCC cells. Next, TMBIM6-modified HCC-MSCs were used to treat HCC cells.

Results

Both HCC-MSCs and their derived exosomes promoted proliferation, invasion, sphere formation ability but suppressed apoptosis in HCC cells (all p < 0.05); however, the effect of HCC-MSCs on these cellular functions was repressed by exosome inhibitor (GW4869). Subsequently, TMBIM6, EEF2, and PRDX1 were sorted out by mRNA sequencing and RT-qPCR validation as candidate genes implicated in the regulation of HCC cellular functions by HCC-MSC-derived exosomes. Among them, TMBIM6 had a potent effect (all p < 0.05), while EEF2 and PRDX1 had less effect on regulating HCC cell viability and invasion. Next, direct silencing TMBIM6 repressed viability, sphere formation, invasion, epithelial-mesenchymal transition (EMT), and PI3K/AKT pathway but promoted apoptosis in HCC cells; however, overexpressing TMBIM6 showed the opposite effect. Furthermore, incubating with exosomes from TMBIM6-modified HCC-MSCs presented a similar effect as direct TMBIM6 modification in HCC cells.

Conclusion

HCC-MSC-derived exosomes transmit TMBIM6 to promote malignant behavior via PI3K/AKT pathway in HCC.

Investigation of the apoptosis-inducing effect of docetaxel by a comprehensive LC-MS based metabolomics and network pharmacology approaches

Docetaxel is one of the clinical first-line drugs and its combination with other chemotherapy agents for advanced or metastatic cancers has attracted widespread attention. Therefore, to promote the clinical application of docetaxel alone or in combination, a comprehensive investigation of the metabolic mechanism of docetaxel is of great importance. Here, we apply an integrative analysis of metabolomics and network pharmacology to elucidate the underlying mechanisms of docetaxel. After taking the intersection of the above two methods, 5 pathways including ABC transporters, Central carbon metabolism in cancer, Glycolysis and Gluconeogenesis, Cysteine and methionine metabolism, and Arginine biosynthesis have been screened out. In concern of the interaction network of these pathways and the anti-apoptosis effect of docetaxel itself, the Central carbon metabolism in cancer pathway was mainly focused. This study may help delineate global landscapes of cellular protein-metabolite interactions, to provide molecular insights about their mechanisms of action, to promote the clinical applications at well.

Combined Targeting of AKT and mTOR Inhibits Tumor Formation of EpCAM+ and CD90+ Human Hepatocellular Carcinoma Cells in an Orthotopic Mouse Model

The epithelial cell adhesion molecule (EpCAM) and Thy-1 cell surface antigen (CD90) have been implicated as cancer stem cell (CSC) markers in hepatocellular carcinoma (HCC). Expression of EpCAM and CD90 on HCC cells is associated with increased tumorigenicity, metastasis and poor prognosis. In this study, we demonstrate that combined treatment with AKT and mTOR inhibitors—i.e., MK2206 and RAD001—results in a synergistic reduction in proliferation of EpCAM+ and CD90+ HCC cells cultured either as adherent cells or as tumoroids in vitro. In addition, tumor growth was reduced by combined treatment with AKT and mTOR inhibitors in an orthotopic xenograft mouse model of an EpCAM+ HCC cell line (Huh7) and primary patient-derived EpCAM+ HCC cells (HCC1) as well as a CD90+ HCC-related cell line (SK-HEP1) in vivo. However, during AKT/mTOR treatment, outgrowth of therapy-resistant tumors was observed in all mice analyzed within a few weeks. Resistance was associated in most cases with restoration of AKT signaling in the tumors, intrahepatic metastases and distant metastases. In addition, an upregulation of the p38 MAPK pathway was identified in the AKT/mTOR inhibitor-resistant tumor cells by kinome profiling. The development of resistant cells during AKT/mTOR therapy was further analyzed by red-green-blue (RGB) marking of HCC cells, which revealed an outgrowth of a large number of Huh7 cells over a period of 6 months. In summary, our data demonstrate that combined treatment with AKT and mTOR inhibitors exhibits synergistic effects on proliferation of EpCAM+ as well as CD90+ HCC cells in vitro. However, the fast development of large numbers of resistant clones under AKT/mTOR therapy observed in vitro and in the orthotopic xenotransplantation mouse model in vivo strongly suggests that this therapy alone will not be sufficient to eliminate EpCAM+ or CD90+ cancer stem cells from HCC patients.