Hepatic stellate cells induce hepatocellular carcinoma cell resistance to sorafenib through the laminin-332/α3 integrin axis recovery of focal adhesion kinase ubiquitination

Targeting tumor extracellular matrix with nanoparticles to circumvent therapeutic resistance

Each stage of tumor development is intrinsically linked to the tumor microenvironment (TME), wherein the extracellular matrix (ECM) serves as a vital and abundant component in tumor tissues. The ECM is a non-cellular, three-dimensional macromolecular network scaffold that provides structural support to cells, stores bioactive molecules, and mediates signaling pathways through specific binding to cell surface receptors. Moreover, the ECM in tumor tissues plays a crucial role in impeding drug diffusion and resisting apoptosis induced by conventional anti-cancer therapies that primarily target cancer cells. Therefore, directing attentions towards the tumor ECM can facilitate the identification of novel targets and the development of new therapies. This review aims to summarize the composition, structure, remodeling, and function of tumor ECM, its association with drug resistance, and current targeting strategies, with a specific emphasis on nanoparticles (NPs).

Advancements in elucidating the mechanisms of Sorafenib resistance in hepatocellular carcinoma

Primary liver cancer is a major global health challenge, of which hepatocellular carcinoma is the most common. For patients with advanced liver cancer, Sorafenib is a first-line targeted drug that occupies a dominant position in clinical applications. Sorafenib is a multi-kinase inhibitor commonly used in clinical practice, which can effectively inhibit tumor cell proliferation, promote cell apoptosis, and inhibit angiogenesis. However, the emergence of drug resistance has hindered the development of treatment programs, which is an urgent problem to be solved. Recent studies have revealed many mechanisms and influencing factors of Sorafenib resistance (such as epigenetic regulation, programmed cell death, metabolic reprogramming, and tumor microenvironment changes). This review not only summarizes the above mechanisms, but also summarizes the combined application of Sorafenib with other drugs (such as molecular targeted drugs, other anti-angiogenesis drugs, cytotoxic drugs, immunotherapy drugs, etc .). Finally, potential strategies and research directions to overcome drug resistance (such as targeting epigenetic pathways or metabolic reprogramming) are discussed to provide suggestions for future in-depth research and clinical applications.

Integrins in Cancer Drug Resistance: Molecular Mechanisms and Clinical Implications

It is estimated that between 80 and 90% of mortality in cancer patients is directly or indirectly related to drug resistance. Consequently, overcoming drug resistance represents a significant challenge in the treatment of cancer. Integrins are transmembrane adhesion molecules that facilitate the linkage between the extracellular matrix (ECM) and the cytoskeleton, thereby enabling the activation of various cellular signaling pathways. Integrins are highly expressed in various cancers and contribute to cancer progression through invasion and metastasis. In addition, recent studies have revealed that integrins play a pivotal role in the development of drug resistance in cancer. This review will first provide an overview of integrin function and classification. It then discusses recent advances in understanding how integrins contribute to drug resistance in cancer, with a focus on ECM, drug transporters, the epithelial-to-mesenchymal transition (EMT), cancer stemness, PD-L1, and glycosylation. Finally, the potential applications of integrins as targets for therapeutic agents against drug-resistant cancers are also summarized.

The role of laminins in cancer pathobiology: a comprehensive review

Laminins (LMs) are a family of heterotrimeric glycoproteins that form the structural foundation of basement membranes (BM). By acting as molecular bridges between cells and the extracellular matrix (ECM) through integrins and other surface receptors, they regulate key cellular signals that influence cell behavior and tissue architecture. Despite their physiological importance, our understanding of the role of LMs in cancer pathobiology remains fragmented. In this article, we review the diverse functions of LMs in promoting cancer cell proliferation, adhesion, and migration-critical steps in cancer metastasis. Beyond their direct effects on tumor cells, LMs influence stromal interactions and modulate tumor microenvironment dynamics, affecting processes such as angiogenesis, immune cell infiltration, cancer-associated fibroblast activation, and immune evasion. Understanding the complex roles of LMs in cancer biology, as well as their differential expression patterns in malignancies, could provide new diagnostic tools for predicting disease outcomes and pave the way for innovative therapeutic strategies, such as targeting LM-receptor interactions or modulating ECM dynamics to impede tumor growth and metastasis.

Aurora kinase A promotes hepatic stellate cell activation and liver fibrosis through the Wnt/β-catenin pathway

AIMS

Aurora kinase A (AURKA) has been implicated in promoting myeloid and renal fibrosis. This study aimed to investigate the impact and underlying mechanism of AURKA on liver fibrosis and to assess the therapeutic potential of MLN8237, a small-molecule AURKA inhibitor, in preventing liver fibrosis in mice.

METHODS

The research used bioinformatics analysis and immunohistochemistry staining on fibrotic liver tissues from human and mouse models to assess AURKA expression. The cellular localization of AURKA was determined through double immunofluorescence staining in human fibrotic liver tissues and primary mouse hepatic stellate cells. RNA interference and AURKA antagonism were used to examine the effects of AURKA on liver fibrosis, while RNA-sequencing, qRT-PCR, and western blotting were employed to elucidate the potential molecular mechanisms of AURKA on hepatic stellate cell activation.

RESULTS

The results showed that AURKA was positively correlated with the progression of liver fibrosis and was predominantly expressed in activated HSCs. Silencing AURKA inhibited HSC activation and proliferation, and induced HSC apoptosis, effects that were similar to those observed with MLN8237 treatment. Additionally, silencing AURKA suppressed the glycogen synthase kinase-3β/β-catenin signaling pathway. Pharmacological inhibition of AURKA phosphorylation also resulted in reduced liver fibrosis in vivo.

CONCLUSION

In conclusion, AURKA may promote HSC activation and liver fibrosis through the Wnt/β-catenin pathway, suggesting its potential as a therapeutic target for liver fibrosis.

The role of inflammasomes in hepatocellular carcinoma: Mechanisms and therapeutic insights

Hepatocellular carcinoma is among the most frequent forms of primary liver cancer and develops within a context of chronic inflammation, frequently associated with a multitude of risk factors, including viral infections, metabolic dysfunction-associated fatty liver disease, metabolic dysfunction-associated steatohepatitis and liver fibrosis. The tumor microenvironment is crucial for the progression of HCC, as immune cells, tumor-associated fibroblasts and hepatic stellate cells interact to promote chronic inflammation and tumor spread. Inflammasomes, the multiprotein complexes that launch the innate immune response, emerge as important mediators in the pathogenesis of HCC. Among others, the inflammasome Nucleotide-binding oligomerization domain, Leucine rich Repeat (NLR) and Pyrin (NLRP) 3 (NLRP3), and absent in melanoma 2 (AIM2), exhibit a dual role in HCC background. It has been reported that they can exert oncosuppressive functions by triggering the inflammatory death of cancer cells. Vice versa, chronic activation contributes to the development of a pro-tumorigenic environment, thus supporting tumor growth. In addition, other inflammasomes such as Nucleotide-binding oligomerization domain, Leucine rich Repeat (NLR) and Pyrin (NLRP) 6 and 12 (NLRP6 and NLRP12, respectively) regulate HCC onset and progression, although more experimental evidence is required. This review focuses on the molecular mechanisms underpinning the inflammasome's contribution to the onset, progression and spread of HCC. Moreover, we will explore the potential therapeutic approaches currently under investigation, which aim to improve the efficacy and reduce the side effects of the treatments currently available. Targeting inflammasomes may be a promising therapeutic strategy for the treatment of HCC, offering new opportunities to improve patient prognosis.

Targeting Hepatic Cancer Stem Cells (CSCs) and Related Drug Resistance by Small Interfering RNA (siRNA)

Tumor recurrence after curative therapy and hepatocellular carcinoma (HCC) cells' resistance to conventional therapies is the reasons for the worse clinical results of HCC patients. A tiny population of cancer cells with a strong potential for self-renewal, differentiation, and tumorigenesis has been identified as cancer stem cells (CSCs). The discovery of CSC surface markers and the separation of CSC subpopulations from HCC cells have been made possible by recent developments in the study of hepatic (liver) CSCs. Hepatic CSC surface markers include epithelial cell adhesion molecules (EpCAM), CD133, CD90, CD13, CD44, OV-6, ALDH, and K19. CSCs have a significant influence on the development of cancer, invasiveness, self-renewal, metastasis, and drug resistance in HCC, and thus provide a therapeutic chance to treat HCC and avoid its recurrence. Therefore, it is essential to develop treatment approaches that specifically and effectively target hepatic stem cells. Given this, one potential treatment approach is to use particular small interfering RNA (siRNA) to target CSC, disrupting their behavior and microenvironment as well as changing their epigenetic state. The characteristics of CSCs in HCC are outlined in this study, along with new treatment approaches based on siRNA that may be used to target hepatic CSCs and overcome HCC resistance to traditional therapies.

A quartet of cancer stem cell niches in hepatocellular carcinoma

Hepatocellular Carcinoma (HCC), the most prevalent type of primary liver cancer, is known for its aggressive behavior and poor prognosis. The Cancer Stem Cell theory, which postulates the presence of a small population of self-renewing cells called Cancer Stem Cells (CSCs), provides insights into various clinical and molecular features of HCC such as tumor heterogeneity, metabolic adaptability, therapy resistance, and recurrence. These CSCs are nurtured in the tumor microenvironment (TME), where a mix of internal and external factors creates a tumor-supportive niche that is continuously evolving both spatially and temporally, thus enhancing the tumor's complexity. This review details the origins of hepatic CSCs (HCSCs) and the factors influencing their stem-like qualities. It highlights the reciprocal crosstalk between HCSCs and the TME (hypoxic, vascular, invasive, and immune niches), exploring the signaling pathways involved and how these interactions control the malignant traits of CSCs. Additionally, it discusses potential therapeutic approaches targeting the HCSC niche and their possible uses in clinical practice.

Hepatocyte transformation is induced by laminin γ2 monomer

Serum laminin-γ2 monomer (Lm-γ2m) is a potent predictive biomarker for hepatocellular carcinoma (HCC) onset in patients with hepatitis C infection who achieve a sustained virologic response with liver cirrhosis (LC) and for the onset of extrahepatic metastases in early-stage HCC. Although Lm-γ2m involvement in late-stage cancer progression has been well investigated, its precise roles in HCC onset remain to be systematically investigated. Therefore, we analyzed an HCC model, human hepatocytes and cholangiocytes, and surgically resected liver tissues from patients with HCC to understand the roles of Lm-γ2m in HCC onset. Ck-19- and EpCAM-positive hepatic progenitor cells (HPCs) in the liver of pdgf-c transgenic HCC mouse model with ductular reaction showed ectopic expression of Lm-γ2m. Forced expression of Lm-γ2m in hepatocytes adjacent to HPCs resulted in enhanced tumorigenicity, cell proliferation, and migration in immortalized hepatocytes, but not in cholangiocytes in vitro. Further, pharmacological inhibition of epidermal growth factor receptor (EGFR) and c-Jun activator JNK suppressed Lm-γ2m-induced hepatocyte transformation, suggesting the involvement of EGFR/c-Jun signaling in the transformation, leading to HCC development. Finally, immunohistochemical staining of HCC tissues revealed a high level of Lm-γ2 expression in the HPCs of the liver with ductular reaction in normal liver adjacent to HCC tissues. Overall, HPC-derived Lm-γ2m in normal liver with ductular reaction acts as a paracrine growth factor on surrounding hepatocytes and promotes their cellular transformation through the EGFR/c-Jun signaling pathway. Furthermore, this is the first report on Lm-γ2m expression detected in the normal liver with ductular reaction, a human precancerous lesion of HCC.

Interplay among extracellular vesicles, cancer stemness and immune regulation in driving hepatocellular carcinoma progression

The intricate interplay among extracellular vesicles, cancer stemness properties, and the immune system significantly impacts hepatocellular carcinoma (HCC) progression, treatment response, and patient prognosis. Extracellular vesicles (EVs), which are membrane-bound structures, play a pivotal role in conveying proteins, lipids, and nucleic acids between cells, thereby serving as essential mediators of intercellular communication. Since a lot of current research focuses on small extracellular vesicles (sEVs), with diameters ranging from 30 nm to 200 nm, this review emphasizes the role of sEVs in the context of interactions between HCC stemness-bearing cells and the immune cells. sEVs offer promising opportunities for the clinical application of innovative diagnostic and prognostic biomarkers in HCC. By specifically targeting sEVs, novel therapeutics aimed at cancer stemness can be developed. Ongoing investigations into the roles of sEVs in cancer stemness and immune regulation in HCC will broaden our understanding and ultimately pave the way for groundbreaking therapeutic interventions.

Linking fatty liver diseases to hepatocellular carcinoma by hepatic stellate cells

Hepatic stellate cells (HSCs), a distinct category of non-parenchymal cells in the liver, are critical for liver homeostasis. In healthy livers, HSCs remain non-proliferative and quiescent. However, under conditions of acute or chronic liver damage, HSCs are activated and participate in the progression and regulation of liver diseases such as liver fibrosis, cirrhosis, and liver cancer. Fatty liver diseases (FLD), including nonalcoholic (NAFLD) and alcohol-related (ALD), are common chronic inflammatory conditions of the liver. These diseases, often resulting from multiple metabolic disorders, can progress through a sequence of inflammation, fibrosis, and ultimately, cancer. In this review, we focused on the activation and regulatory mechanism of HSCs in the context of FLD. We summarized the molecular pathways of activated HSCs (aHSCs) in mediating FLD and their role in promoting liver tumor development from the perspectives of cell proliferation, invasion, metastasis, angiogenesis, immunosuppression, and chemo-resistance. We aimed to offer an in-depth discussion on the reciprocal regulatory interactions between FLD and HSC activation, providing new insights for researchers in this field.

Integrinβ-1 in disorders and cancers: molecular mechanisms and therapeutic targets

Integrinβ-1 (ITGB1) is a crucial member of the transmembrane glycoprotein signaling receptor family and is also central to the integrin family. It forms heterodimers with other ligands, participates in intracellular signaling and controls a variety of cellular processes, such as angiogenesis and the growth of neurons; because of its role in bidirectional signaling regulation both inside and outside the membrane, ITGB1 must interact with a multitude of substances, so a variety of interfering factors can affect ITGB1 and lead to changes in its function. Over the past 20 years, many studies have confirmed a clear causal relationship between ITGB1 dysregulation and cancer development and progression in a wide range of benign diseases and solid tumor types, which may imply that ITGB1 is a prognostic biomarker and a therapeutic target for cancer treatment that warrants further investigation. This review summarizes the biological roles of ITGB1 in benign diseases and cancers, and compiles the current status of ITGB1 function and therapy in various aspects of tumorigenesis and progression. Finally, future research directions and application prospects of ITGB1 are suggested. Video Abstract.

Focal adhesion kinase confers lenvatinib resistance in hepatocellular carcinoma via the regulation of lysine-deficient kinase 1

Lenvatinib is a clinically effective multikinase inhibitor approved for first-line therapy of advanced hepatocellular carcinoma (HCC). Although resistance against lenvatinib often emerges and limits its antitumor activity, the underlying molecular mechanisms involved in endogenous and acquired resistance remain elusive. In this study, we identified focal adhesion kinase (FAK) as a critical contributor to lenvatinib resistance in HCC. The elevated expression and phosphorylation of FAK were observed in both acquired and endogenous lenvatinib-resistant (LR) HCC cells. Furthermore, inhibition of FAK reversed lenvatinib resistance in vitro and in vivo. Mechanistically, FAK promoted lenvatinib resistance through regulating lysine-deficient kinase 1 (WNK1). Phosphorylation of WNK1 was significantly increased in LR-HCC cells. Further, WNK1 inhibitor WNK463 resensitized either established or endogenous LR-HCC cells to lenvatinib treatment. In addition, overexpression of WNK1 desensitized parental HCC cells to lenvatinib treatment. Conclusively, our results establish a crucial role and novel mechanism of FAK in lenvatinib resistance and suggest that targeting the FAK/WNK1 axis is a promising therapeutic strategy in HCC patients showing lenvatinib resistance.

Dynamic regulation of EXO1 promotes the progression from liver fibrosis to HCC through TGF-β1/Smad signaling feedback loop

BACKGROUND

HSCs are the main stromal cells in the process of liver fibrosis and accelerate HCC progression. Previous studies determined that highly expressed exonuclease 1 (EXO1) increases the malignant behavior of HCC cells and is closely related to liver cirrhosis. This study aimed to explore the roles and mechanisms of EXO1 in the development of liver cirrhosis and HCC.

METHODS

We fully demonstrated that EXO1 expression was positively correlated with liver fibrosis and cirrhotic HCC by combining bioinformatics, hepatic fibrosis mouse models, and human HCC tissues. The role of EXO1 in a murine HCC model induced by activated forms of AKT and Ras oncogenes (AKT/Ras) was investigated by employing an adeno-associated virus-mediated EXO1 knockdown technique.

RESULTS

The knockdown of EXO1 promoted a regression of HCC in AKT/Ras mice and reduced the degree of liver fibrosis. Downregulated EXO1 inhibited LX-2 cell activation and inhibited the proliferation and migration of HCC cells. Moreover, conditioned medium of LX-2 cells with EXO1 overexpression increased the proliferation and migration of HCC cells, which was attenuated after EXO1 knockout in LX-2 cells. EXO1 knockdown attenuated the role of LX-2 in promoting HepG2 xenograft growth in vivo. Mechanistically, EXO1 promotes the activation of the downstream TGF-β-smad2/3 signaling in LX-2 and HCC cells. Interestingly, increased TGF-β-smad2/3 signaling had a feedback effect on EXO1, which sustains EXO1 expression and continuously stimulates the activation of HSCs.

CONCLUSIONS

EXO1 forms a positive feedback circuit with TGF-β-Smad2/3 signaling and promotes the activation of HSCs, which accelerates HCC progression. Those findings indicate EXO1 may be a promising target for the diagnosis and treatment of cirrhotic HCC.

A key driver to promote HCC: Cellular crosstalk in tumor microenvironment

Liver cancer is the third greatest cause of cancer-related mortality, which of the major pathological type is hepatocellular carcinoma (HCC) accounting for more than 90%. HCC is characterized by high mortality and is predisposed to metastasis and relapse, leading to a low five-year survival rate and poor clinical prognosis. Numerous crosstalk among tumor parenchymal cells, anti-tumor cells, stroma cells, and immunosuppressive cells contributes to the immunosuppressive tumor microenvironment (TME), in which the function and frequency of anti-tumor cells are reduced with that of associated pro-tumor cells increasing, accordingly resulting in tumor malignant progression. Indeed, sorting out and understanding the signaling pathways and molecular mechanisms of cellular crosstalk in TME is crucial to discover more key targets and specific biomarkers, so that develop more efficient methods for early diagnosis and individualized treatment of liver cancer. This piece of writing offers insight into the recent advances in HCC-TME and reviews various mechanisms that promote HCC malignant progression from the perspective of mutual crosstalk among different types of cells in TME, aiming to assist in identifying the possible research directions and methods in the future for discovering new targets that could prevent HCC malignant progression.

The critical role of circular RNAs in drug resistance in gastrointestinal cancers

Nowadays, drug resistance (DR) in gastrointestinal (GI) cancers, as the main reason for cancer-related mortality worldwide, has become a serious problem in the management of patients. Several mechanisms have been proposed for resistance to anticancer drugs, including altered transport and metabolism of drugs, mutation of drug targets, altered DNA repair system, inhibited apoptosis and autophagy, cancer stem cells, tumor heterogeneity, and epithelial-mesenchymal transition. Compelling evidence has revealed that genetic and epigenetic factors are strongly linked to DR. Non-coding RNA (ncRNA) interferences are the most crucial epigenetic alterations explored so far, and among these ncRNAs, circular RNAs (circRNAs) are the most emerging members known to have unique properties. Due to the absence of 5' and 3' ends in these novel RNAs, the two ends are covalently bonded together and are generated from pre-mRNA in a process known as back-splicing, which makes them more stable than other RNAs. As far as the unique structure and function of circRNAs is concerned, they are implicated in proliferation, migration, invasion, angiogenesis, metastasis, and DR. A clear understanding of the molecular mechanisms responsible for circRNAs-mediated DR in the GI cancers will open a new window to the management of GI cancers. Hence, in the present review, we will describe briefly the biogenesis, multiple features, and different biological functions of circRNAs. Then, we will summarize current mechanisms of DR, and finally, discuss molecular mechanisms through which circRNAs regulate DR development in esophageal cancer, pancreatic cancer, gastric cancer, colorectal cancer, and hepatocellular carcinoma.

Extracellular matrix remodeling in tumor progression and immune escape: from mechanisms to treatments

The malignant tumor is a multi-etiological, systemic and complex disease characterized by uncontrolled cell proliferation and distant metastasis. Anticancer treatments including adjuvant therapies and targeted therapies are effective in eliminating cancer cells but in a limited number of patients. Increasing evidence suggests that the extracellular matrix (ECM) plays an important role in tumor development through changes in macromolecule components, degradation enzymes and stiffness. These variations are under the control of cellular components in tumor tissue via the aberrant activation of signaling pathways, the interaction of the ECM components to multiple surface receptors, and mechanical impact. Additionally, the ECM shaped by cancer regulates immune cells which results in an immune suppressive microenvironment and hinders the efficacy of immunotherapies. Thus, the ECM acts as a barrier to protect cancer from treatments and supports tumor progression. Nevertheless, the profound regulatory network of the ECM remodeling hampers the design of individualized antitumor treatment. Here, we elaborate on the composition of the malignant ECM, and discuss the specific mechanisms of the ECM remodeling. Precisely, we highlight the impact of the ECM remodeling on tumor development, including proliferation, anoikis, metastasis, angiogenesis, lymphangiogenesis, and immune escape. Finally, we emphasize ECM "normalization" as a potential strategy for anti-malignant treatment.

Integrins in human hepatocellular carcinoma tumorigenesis and therapy

ABSTRACT

Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.

Deciphering the possible reciprocal loop between hepatic stellate cells and cancer cells in the tumor microenvironment of the liver

Activated hepatic stellate cells (HSCs)/myofibroblasts are the important sources of cancer-associated fibroblasts in the liver tumor microenvironment (TME). The crosstalk between activated HSCs and tumor cells mediates HCC progression, metastasis, tumor cell survival, angiogenesis and chemoresistance. In TME, HCC cells secrete various soluble factors responsible for the phenotypic activation of quiescent HSCs. Tumor cells use activated HSC-derived extracellular matrix (ECM) for migration and invasion. Further, in liver TME, activated HSCs and sinusoidal endothelial cells engage in a crosstalk that causes the secretion of angiogenesis and metastasis-related growth factors and cytokines. Activated HSCs and immune cells crosstalk to decrease immune surveillance in the liver TME by increasing the population of T regulatory cells and M2 macrophages or myeloid-derived suppressor cells. Thus, HSCs play a vital role in liver TME cell interactions. Therefore, a deep understanding of HSCs activation and their crosstalk with cancer and immune cells in TME may lead to the development of novel therapeutic strategies to target HCC.

Biological impact and therapeutic perspective of targeting PI3K/Akt signaling in hepatocellular carcinoma: Promises and Challenges

Cancer progression results from activation of various signaling networks. Among these, PI3K/Akt signaling contributes to proliferation, invasion, and inhibition of apoptosis. Hepatocellular carcinoma (HCC) is a primary liver cancer with high incidence rate, especially in regions with high prevalence of viral hepatitis infection. Autoimmune disorders, diabetes mellitus, obesity, alcohol consumption, and inflammation can also lead to initiation and development of HCC. The treatment of HCC depends on the identification of oncogenic factors that lead tumor cells to develop resistance to therapy. The present review article focuses on the role of PI3K/Akt signaling in HCC progression. Activation of PI3K/Akt signaling promotes glucose uptake, favors glycolysis and increases tumor cell proliferation. It inhibits both apoptosis and autophagy while promoting HCC cell survival. PI3K/Akt stimulates epithelial-to-mesenchymal transition (EMT) and increases matrix-metalloproteinase (MMP) expression during HCC metastasis. In addition to increasing colony formation capacity and facilitating the spread of tumor cells, PI3K/Akt signaling stimulates angiogenesis. Therefore, silencing PI3K/Akt signaling prevents aggressive HCC cell behavior. Activation of PI3K/Akt signaling can confer drug resistance, particularly to sorafenib, and decreases the radio-sensitivity of HCC cells. Anti-cancer agents, like phytochemicals and small molecules can suppress PI3K/Akt signaling by limiting HCC progression. Being upregulated in tumor tissues and clinical samples, PI3K/Akt can also be used as a biomarker to predict patients' response to therapy.

Cancer Stem Cell and Hepatic Stellate Cells in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common liver cancer. It is highly lethal and has high recurrence. Death among HCC patients occur mainly due to tumor progression, recurrence, metastasis, and chemoresistance. Cancer stem cells (CSCs) are cell subpopulations within the tumor that promote invasion, recurrence, metastasis, and drug resistance. Hepatic stellate cells (HSCs) are important components of the tumor microenvironment (TME) responsible for primary secretory ECM proteins during liver injury and inflammation. These cells promote fibrogenesis, infiltrate the tumor stroma, and contribute to HCC development. Interactions between HSC and CSC and their microenvironment help promote carcinogenesis through different mechanisms. This review summarizes the roles of CSCs and HSCs in establishing the TME in primary liver tumors and describes their involvement in HCC chemoresistance.

A comprehensive review of the relationship between autophagy and sorafenib-resistance in hepatocellular carcinoma: ferroptosis is noteworthy

Patients with hepatocellular carcinoma (HCC) bear a heavy burden of disease and economic burden but have fewer treatment options. Sorafenib, a multi-kinase inhibitor, is the only approved drug that can be used to limit the progression of inoperable or distant metastatic HCC. However, enhanced autophagy and other molecular mechanisms after sorafenib exposure further induce drug resistance in HCC patients. Sorafenib-associated autophagy also generates a series of biomarkers, which may represent that autophagy is a critical section of sorafenib-resistance in HCC. Furthermore, many classic signaling pathways have been found to be involved in sorafenib-associated autophagy, including the HIF/mTOR signaling pathway, endoplasmic reticulum stress, and sphingolipid signaling, among others. In turn, autophagy also provokes autophagic activity in components of the tumor microenvironment, including tumor cells and stem cells, further impacting sorafenib-resistance in HCC through a special autophagic cell death process called ferroptosis. In this review, we summarized the latest research progress and molecular mechanisms of sorafenib-resistance-associated autophagy in detail, providing new insights and ideas for unraveling the dilemma of sorafenib-resistance in HCC.

Activated Hepatic Stellate Cells in Hepatocellular Carcinoma: Their Role as a Potential Target for Future Therapies

Hepatocellular carcinoma (HCC) is a global healthcare challenge, which affects more than 815,000 new cases every year. Activated hepatic stellate cells (aHSCs) remain the principal cells that drive HCC onset and growth. aHSCs suppress the anti-tumor immune response through interaction with different immune cells. They also increase the deposition of the extracellular matrix proteins, challenging the reversion of fibrosis and increasing HCC growth and metastasis. Therapy for HCC was reported to activate HSCs, which could explain the low efficacy of current treatments. Conversely, recent studies aimed at the deactivation of HSCs show that they have been able to inhibit HCC growth. In this review article, we discuss the role of aHSCs in HCC pathophysiology and therapy. Finally, we provide suggestions for the experimental implementation of HSCs in HCC therapies.

Curcumin and berberine co-loaded liposomes for anti-hepatocellular carcinoma therapy by blocking the cross-talk between hepatic stellate cells and tumor cells

Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment (TME). In hepatocellular carcinoma (HCC), quiescent hepatic stellate cells (HSCs) could be activated to become CAFs, which play a critical role in tumor progression and drug resistance. Therefore, recent efforts have been focused on combining anti-HSC and pro-apoptotic activities to improve anti-tumor efficacy of drugs. In this study, glycyrrhetinic acid and hyaluronic acid–modified liposomes (GA-HA-Lip) were prepared for co-delivery of curcumin (CUR) and berberine (BBR) for the treatment of HCC. Furthermore, we established the LX-2+BEL-7402 co-cultured cell model and implanted the m-HSCs+H22 cells into a mouse to evaluate the anti-tumor effect of CUR&BBR/GA-HA-Lip both in vitro and in vivo. The results showed that CUR&BBR/GA-HA-Lip could accumulate in tumor tissues and be taken up by HSCs and BEL-7402 cells simultaneously. Compared with free CUR, the combination therapy based on GA-HA-Lip exhibits stronger pro-apoptotic and anti-proliferation effect both in vitro and in vivo. The anti-tumor mechanistic study revealed that CUR&BBR/GA-HA-Lip could inhibit the activation of HSCs and restrain drug resistance of tumor cells. In summary, CUR&BBR/GA-HA-Lip could be a promising nano-sized formulation for anti-tumor therapy.

Ets1 mediates sorafenib resistance by regulating mitochondrial ROS pathway in hepatocellular carcinoma

The incidence and mortality of hepatocellular carcinoma (HCC) are on a rise in the Western countries including US, attributed mostly to late detection. Sorafenib has been the first-line FDA-approved drug for advanced unresectable HCC for almost a decade, but with limited efficacy due to the development of resistance. More recently, several other multi-kinase inhibitors (lenvatinib, cabozantinib, regorafenib), human monoclonal antibody (ramucirumab), and immune checkpoint inhibitors (nivolumab, pembrolizumab) have been approved as systemic therapies. Despite this, the median survival of patients is not significantly increased. Understanding of the molecular mechanism(s) that govern HCC resistance is critically needed to increase efficacy of current drugs and to develop more efficacious ones in the future. Our studies with sorafenib-resistant (soraR) HCC cells using transcription factor RT² Profiler PCR Arrays revealed an increase in E26 transformation-specific-1 (Ets-1) transcription factor in all soraR cells. HCC TMA studies showed an increase in Ets-1 expression in advanced HCC compared to the normal livers. Overexpression or knocking down Ets-1 modulated sorafenib resistance-related epithelial-mesenchymal transition (EMT), migration, and cell survival. In addition, the soraR cells showed a significant reduction of mitochondrial damage and mitochondrial reactive oxygen species (mROS) generation, which were antagonized by knocking down Ets-1 expression. More in-depth analysis identified GPX-2 as a downstream mediator of Ets-1-induced sorafenib resistance, which was down-regulated by Ets-1 knockdown while other antioxidant pathway genes were not affected. Interestingly, knocking down GPX2 expression significantly increased sorafenib sensitivity in the soraR cells. Our studies indicate the activation of a novel Ets-1-GPX2 signaling axis in soraR cells, targeting which might successfully antagonize resistance and increase efficacy.

New insights into antiangiogenic therapy resistance in cancer: Mechanisms and therapeutic aspects

Angiogenesis is a hallmark of cancer and is required for tumor growth and progression. Antiangiogenic therapy has been revolutionarily developing and was approved for the treatment of various types of cancer for nearly two decades, among which bevacizumab and sorafenib continue to be the two most frequently used antiangiogenic drugs. Although antiangiogenic therapy has brought substantial survival benefits to many cancer patients, resistance to antiangiogenic drugs frequently occurs during clinical treatment, leading to poor outcomes and treatment failure. Cumulative evidence has demonstrated that the intricate interplay among tumor cells, bone marrow-derived cells, and local stromal cells critically allows for tumor escape from antiangiogenic therapy. Currently, drug resistance has become the main challenge that hinders the therapeutic efficacies of antiangiogenic therapy. In this review, we describe and summarize the cellular and molecular mechanisms conferring tumor drug resistance to antiangiogenic therapy, which was predominantly associated with redundancy in angiogenic signaling molecules (e.g., VEGFs, GM-CSF, G-CSF, and IL17), alterations in biological processes of tumor cells (e.g., tumor invasiveness and metastasis, stemness, autophagy, metabolic reprogramming, vessel co-option, and vasculogenic mimicry), increased recruitment of bone marrow-derived cells (e.g., myeloid-derived suppressive cells, tumor-associated macrophages, and tumor-associated neutrophils), and changes in the biological functions and features of local stromal cells (e.g., pericytes, cancer-associated fibroblasts, and endothelial cells). We also review potential biomarkers to predict the response to antiangiogenic therapy in cancer patients, which mainly consist of imaging biomarkers, cellular and extracellular proteins, a certain type of bone marrow-derived cells, local stromal cell content (e.g., pericyte coverage) as well as serum or plasma biomarkers (e.g., non-coding RNAs). Finally, we highlight the recent advances in combination strategies with the aim of enhancing the response to antiangiogenic therapy in cancer patients and mouse models. This review introduces a comprehensive understanding of the mechanisms and biomarkers associated with the evasion of antiangiogenic therapy in cancer, providing an outlook for developing more effective approaches to promote the therapeutic efficacy of antiangiogenic therapy.

The Tumor Microenvironment Drives Intrahepatic Cholangiocarcinoma Progression

Intrahepatic cholangiocarcinoma (iCCA) is a highly aggressive cancer with limited therapeutic options and short overall survival. iCCA is characterized by a strong desmoplastic reaction in the surrounding ecosystem that likely affects tumoral progression. Overexpression of the Notch pathway is implicated in iCCA development and progression. Our aim was to investigate the effectiveness of Crenigacestat, a selective inhibitor of NOTCH1 signaling, against the cross-talk between cancer cells and the surrounding ecosystem in an in vivo HuCCT1-xenograft model. In the present study, a transcriptomic analysis approach, validated by Western blotting and qRT-PCR on iCCA tumor masses treated with Crenigacestat, was used to study the molecular pathways responsive to drug treatment. Our results indicate that Crenigacestat significantly inhibited NOTCH1 and HES1, whereas tumor progression was not affected. In addition, the drug triggered a strong immune response and blocked neovascularization in the tumor ecosystem of the HuCCT1-xenograft model without affecting the occurrence of fibrotic reactions. Therefore, although these data need further investigation, our observations confirm that Crenigacestat selectively targets NOTCH1 and that the desmoplastic response in iCCA likely plays a key role in both drug effectiveness and tumor progression.

Hepatocellular Carcinoma: Molecular Pathogenesis and Therapeutic Advances

Hepatocellular carcinoma (HCC), the most common form of liver cancer, continues to be a serious medical problem with poor prognosis, without major therapeutic improvement for years and increasing incidence. Fortunately, advances in systemic treatment options are finally arriving for HCC patients. After a decade of sorafenib as a standard therapy for advanced HCC, several tyrosine kinase inhibitors (TKIs), antiangiogenic antibodies, and immune checkpoint inhibitors have reached the clinic. Although infections by hepatitis B virus and hepatitis C virus remain principal factors for HCC development, the rise of non- alcoholic steatohepatitis from diabetes mellitus or metabolic syndrome is impeding HCC decline. Knowledge of specific molecular mechanisms, based on the etiology and the HCC microenvironment that influence tumor growth and immune control, will be crucial for physician decision-making among a variety of drugs to prescribe. In addition, markers of treatment efficacy are needed to speed the movement of patients towards other potentially effective treatments. Consequently, research to provide scientific data for the evidence-based management of liver cancer is guaranteed in the coming years and discussed here.

β-arrestin2 regulating β2-adrenergic receptor signaling in hepatic stellate cells contributes to hepatocellular carcinoma progression

Background: β-arrestin2 and β2-adrenergic receptor (β2-AR) have important roles in malignant tumors, the present study aims to investigate the role of activated β2-AR in hepatic stellate cells (HSCs) during hepatocellular carcinoma (HCC) progression and the regulatory effect of β-arrestin2.

Methods: Immunofluorescence and Western blot were used to detect the expression of β-arrestin2 and β2-AR in HSCs of liver tissues from human HCC samples and diethylnitrosamine (DEN)-induced HCC model mice. We next used β-arrestin2^-/- mice to demonstrate the regulatory role of β-arrestin2 in DEN mice. The subsets of T cells were quantified by flow cytometry. MTT and wound healing assay were applied to detect the proliferation and migration of cells. Co-immunoprecipitation assay was used to detect the link of β-arrestin2 and β2-AR in HSCs. Effect of β-arrestin2 overexpression on β2-AR downstream signaling pathway was verified by Western blot. The secretion of CCL2 was detected by ELISA.

Results: The expression of β2-AR was significantly increased, while β-arrestin2 was decreased in HSCs of HCC tissues. And β-arrestin2 deficiency exacerbates DEN-induced HCC accompanied with increased β2-AR expression. The results of flow cytometry showed that the percentage of activated T cells decreased gradually after DEN injection. β-arrestin2 knockout down-regulated the ratio of activated T cells. In vitro, selective activation of β2-AR in HSCs promoted the proliferation and migration of HCC cells. β-arrestin2 overexpression enhanced co-immunoprecipitation of β-arrestin2 and β2-AR in activated HSCs, and decreased its downstream Akt phosphorylation. Akt inhibitor decreased secretion of CCL2 in activated HSCs.

Conclusion: Our study demonstrated that β2-AR activation in HSCs induces the proliferation and migration of HCC cells may be through Akt signaling, and this effect appears to be regulated by β-arrestin2.

Validation of a Lab-on-Chip Assay for Measuring Sorafenib Effectiveness on HCC Cell Proliferation

Hepatocellular carcinoma (HCC) is a highly lethal cancer, and although a few drugs are available for treatment, therapeutic effectiveness is still unsatisfactory. New drugs are urgently needed for hepatocellular carcinoma (HCC) patients. In this context, reliable preclinical assays are of paramount importance to screen the effectiveness of new drugs and, in particular, measure their effects on HCC cell proliferation. However, cell proliferation measurement is a time-consuming and operator-dependent procedure. The aim of this study was to validate an engineered miniaturized on-chip platform for real-time, non-destructive cell proliferation assays and drug screening. The effectiveness of Sorafenib, the first-line drug mainly used for patients with advanced HCC, was tested in parallel, comparing the gold standard 96-well-plate assay and our new lab-on-chip platform. Results from the lab-on-chip are consistent in intra-assay replicates and comparable to the output of standard crystal violet proliferation assays for assessing Sorafenib effectiveness on HCC cell proliferation. The miniaturized platform presents several advantages in terms of lesser reagents consumption, operator time, and costs, as well as overcoming a number of technical and operator-dependent pitfalls. Moreover, the number of cells required is lower, a relevant issue when primary cell cultures are used. In conclusion, the availability of inexpensive on-chip assays can speed up drug development, especially by using patient-derived samples to take into account disease heterogeneity and patient-specific characteristics.

Focal adhesion kinase inhibitor TAE226 combined with Sorafenib slows down hepatocellular carcinoma by multiple epigenetic effects

Background

Hepatocellular carcinoma (HCC) is one of the most common and lethal malignant tumours worldwide. Sorafenib (SOR) is one of the most effective single-drug systemic therapy against advanced HCC, but the identification of novel combination regimens for a continued improvement in overall survival is a big challenge. Recent studies highlighted the crucial role of focal adhesion kinase (FAK) in HCC growth. The aim of this study was to investigate the antitumor effects of three different FAK inhibitors (FAKi), alone or in combination with SOR, using in vitro and in vivo models of HCC.

Methods

The effect of PND1186, PF431396, TAE226 on cell viability was compared to SOR. Among them TAE226, emerging as the most effective FAKi, was tested alone or in combination with SOR using 2D/3D human HCC cell line cultures and HCC xenograft murine models. The mechanisms of action were assessed by gene/protein expression and imaging approaches, combined with high-throughput methods.

Results

TAE226 was the more effective FAKi to be combined with SOR against HCC. Combined TAE226 and SOR treatment reduced HCC growth both in vitro and in vivo by affecting tumour-promoting gene expression and inducing epigenetic changes via dysregulation of FAK nuclear interactome. We characterized a novel nuclear functional interaction between FAK and the NuRD complex. TAE226-mediated FAK depletion and SOR-promoted MAPK down-modulation caused a decrease in the nuclear amount of HDAC1/2 and a consequent increase of the histone H3 lysine 27 acetylation, thus counteracting histone H3 lysine 27 trimethylation.

Conclusions

Altogether, our findings provide the first evidence that TAE226 combined with SOR efficiently reduces HCC growth in vitro and in vivo. Also, our data highlight that deep analysis of FAK nuclear interactome may lead to the identification of new promising targets for HCC therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02154-8.

Magnetic implants in vivo guiding sorafenib liver delivery by superparamagnetic solid lipid nanoparticles

HYPOTHESIS

Solid lipid nanoparticles (SLNs), co-encapsulating superparamagnetic iron oxide nanoparticles and sorafenib, have been exploited for magnetic-guided drug delivery to the liver. Two different magnetic configurations, both comprising two small magnets, were under-skin implanted to investigate the effect of the magnetic field topology on the magnetic SLNP accumulation in liver tissues. A preliminary simulation analysis was performed to predict the magnetic field topography for each tested configuration.

EXPERIMENTS

SLNs were prepared using a hot homogenization approach and characterized using complementary techniques. Their in vitro biological behavior was assessed in HepG-2 liver cancer cells; wild-type mice were used for the in vivo study. The magnet configuration that resulted in a higher magnetic targeting efficiency was investigated by evaluating the iron content in homogenated murine liver tissues.

FINDINGS

SLNs, characterized by an average size smaller than 200 nm, retained their superparamagnetic behavior and relevant molecular resonance imaging properties as negative contrast agents. The evaluation of iron accumulation in the liver tissues was consistent with the magnetic induction profile of each magnet configuration, concurring with the results predicted by simulation analysis and obtained by measurements in living mice.

Hepatic stellate cells in the injured liver: Perspectives beyond hepatic fibrosis

Over the last two decades, our understanding of the pathological role of hepatic stellate cells (HSCs) in fibrotic liver disease has increased dramatically. As HSCs are identified as the principal collagen-producing cells in the injured liver, several experimental and clinical studies have targeted HSCs to treat liver fibrosis. However, HSCs also play a critical role in developing nonfibrotic liver diseases such as cholestasis, portal hypertension, and hepatocellular carcinoma (HCC). Therefore, this review exclusively focuses on the role of activated HSCs beyond hepatic fibrosis. In cholestasis conditions, elevated bile salts and bile acids activate HSCs to secrete collagen and other extracellular matrix products, which cause biliary fibrosis and cholangitis. In the chronically injured liver, autocrine and paracrine signaling from liver sinusoidal endothelial cells activates HSCs to induce portal hypertension via endothelin-1 release. In the tumor microenvironment (TME), activated HSCs are the major source of cancer-associated fibroblasts (CAF). The crosstalk between activated HSC/CAF and tumor cells is associated with tumor cell proliferation, migration, metastasis, and chemoresistance. In TME, activated HSCs convert macrophages to tumor-associated macrophages and induce the differentiation of dendritic cells (DCs) and monocytes to regulatory DCs and myeloid-derived suppressor cells, respectively. This differentiation, in turn, increases T cells proliferation and induces their apoptosis leading to reduced immune surveillance in TME. Thus, HSCs activation in chronically injured liver is a critical process involved in the progression of cholestasis, portal hypertension, and liver cancer.

The metabolic flexibility of quiescent CSC: implications for chemotherapy resistance

Quiescence has been observed in stem cells (SCs), including adult SCs and cancer SCs (CSCs). Conventional chemotherapies mostly target proliferating cancer cells, while the quiescent state favors CSCs escape to chemotherapeutic drugs, leaving risks for tumor recurrence or metastasis. The tumor microenvironment (TME) provides various signals that maintain resident quiescent CSCs, protect them from immune surveillance, and facilitates their recurrence potential. Since the TME has the potential to support and initiate stem cell-like programs in cancer cells, targeting the TME components may prove to be a powerful modality for the treatment of chemotherapy resistance. In addition, an increasing number of studies have discovered that CSCs exhibit the potential of metabolic flexibility when metabolic substrates are limited, and display increased robustness in response to stress. Accompanied by chemotherapy that targets proliferative cancer cells, treatments that modulate CSC quiescence through the regulation of metabolic pathways also show promise. In this review, we focus on the roles of metabolic flexibility and the TME on CSCs quiescence and further discuss potential treatments of targeting CSCs and the TME to limit chemotherapy resistance.

Hepatic Stellate Cell: A Potential Target for Hepatocellular Carcinoma

Liver cancer is a leading cause of cancer-related death worldwide, in which hepatocellular carcinoma (HCC) accounts for the majority. Despite the progression in treatment, the prognosis remains extremely poor for HCC patients. The mechanisms of hepatocarcinogenesis are complex, of which fibrosis is acknowledged as the pre-cancerous stage of HCC. Approximately, 80-90% of HCC develops in the fibrotic or cirrhotic livers. Hepatic stellate cells (HSCs), the main effector cells of liver fibrosis, could secret various biological contents to maintain the liver inflammation. By decades, HSCs are increasingly correlated with HCC in the tumor microenvironment. In this review, we summarized the underlying mechanisms that HSCs participated in the genesis and progression of HCC. HSCs secrete various bioactive contents and regulate tumor-related pathways, subsequently contribute to metastasis, angiogenesis, immunosuppression, chemoresistance and cancer stemness. The study indicates that HSC plays vital roles in HCC progression, suggesting it as a promising therapeutic target for HCC treatment.

Y-box binding protein 1 augments sorafenib resistance via the PI3K/Akt signaling pathway in hepatocellular carcinoma

BACKGROUND

Sorafenib is the first-line treatment for patients with advanced hepatocellular carcinoma (HCC). Y-box binding protein 1 (YB-1) is closely correlated with tumors and drug resistance. However, the relationship between YB-1 and sorafenib resistance and the underlying mechanism in HCC remain unknown.

AIM

To explore the role and related mechanisms of YB-1 in mediating sorafenib resistance in HCC.

METHODS

The protein expression levels of YB-1 were assessed in human HCC tissues and adjacent nontumor tissues. Next, we constructed YB-1 overexpression and knockdown hepatocarcinoma cell lines with lentiviruses and stimulated these cell lines with different concentrations of sorafenib. Then, we detected the proliferation and apoptosis in these cells by terminal deoxynucleotidyl transferase dUTP nick end labeling, flow cytometry and Western blotting assays. We also constructed a xenograft tumor model to explore the effect of YB-1 on the efficacy of sorafenib in vivo. Moreover, we studied and verified the specific molecular mechanism of YB-1 mediating sorafenib resistance in hepatoma cells by digital gene expression sequencing (DGE-seq).

RESULTS

YB-1 protein levels were found to be higher in HCC tissues than in corresponding nontumor tissues. YB-1 suppressed the effect of sorafenib on cell proliferation and apoptosis. Consistently, the efficacy of sorafenib in vivo was enhanced after YB-1 was knocked down. Furthermore, KEGG pathway enrichment analysis of DGE-seq demonstrated that the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway was essential for the sorafenib resistance induced by YB-1. Subsequently, YB-1 interacted with two key proteins of the PI3K/Akt signaling pathway (Akt1 and PIK3R1) as shown by searching the BioGRID and HitPredict websites. Finally, YB-1 suppressed the inactivation of the PI3K/Akt signaling pathway induced by sorafenib, and the blockade of the PI3K/Akt signaling pathway by LY294002 mitigated YB-1-induced sorafenib resistance.

CONCLUSION

Overall, we concluded that YB-1 augments sorafenib resistance through the PI3K/Akt signaling pathway in HCC and suggest that YB-1 is a key drug resistance-related gene, which is of great significance for the application of sorafenib in advanced-stage HCC.

Combined anti-hepatocellular carcinoma therapy inhibit drug-resistance and metastasis via targeting "substance P-hepatic stellate cells-hepatocellular carcinoma" axis

Peripheral nerves have emerged as the important components in tumor microenvironment (TME), which could activate hepatic stellate cells (HSCs) by secreting substance P (SP), leading to hepatocellular carcinoma (HCC) invasion and metastasis. Herein, we proposed a novel anti-HCC concept of blocking "SP-HSCs-HCC" axis for omnidirectional inhibition of HCC development. To pursue this aim, the novel CAP/GA-sHA-DOX NPs were developed for targeted co-delivery of capsaicin (CAP) and doxorubicin (DOX) using glycyrrhetinic acid (GA) modified sulfated-HA (sHA) as nanocarriers. Among that, CAP could inhibit the activation of HSCs as an inhibitor of SP. Notably, to real mimic "SP-HSCs-HCC" axis for in vitro and in vivo evaluation, both "SP + LX-2+BEL-7402" co-cultured cell model and "SP + m-HSC + H22" co-implantation mice model were attempted for the first time. Furthermore, in vivo anti-HCC effects were performed in three different tumor-bearing models: subcutaneous implantation of H22 or "SP + m-HSC + H22", intravenous injection of H22 for lung metastasis, and orthotopic implantation of H22 for primary HCC. Our results showed that CAP/GA-sHA-DOX NPs could be efficiently taken up by tumor cells and activated HSCs (aHSCs) simultaneously, and effectively inhibit tumor drug-resistance and migration by blocking SP-induced HSCs activation. In addition, CAP/GA-sHA-DOX NPs exhibited low ECM deposition, less tumor angiogenesis, and superior in vivo anti-HCC effects. The anti-HCC mechanisms revealed that CAP/GA-sHA-DOX NPs could down-regulate the expression level of Vimentin and P-gp, reverse epithelial-mesenchymal transition (EMT) of tumor cells. In brief, the nano-sized combination therapy based on GA-sHA-DOX polymers could effectively inhibit drug-resistance and metastasis of HCC by blocking "SP-HSCs-HCC" axis, which provides a promising approach for cancer therapy.

Periostin deficiency reduces diethylnitrosamine-induced liver cancer in mice by decreasing hepatic stellate cell activation and cancer cell proliferation

Periostin is a critical extracellular regulator in the pathogenesis of liver disorders such as hepatosteatosis, non-alcoholic steatohepatitis, inflammation, and fibrosis. Periostin is also involved in the progression of hepatocellular carcinoma (HCC). However, the molecular mechanisms of periostin in hepatic stellate cell (HSC) activation and tumor cell proliferation in the pathogenesis of HCC remain largely unknown. We demonstrate that periostin is markedly upregulated in diethylnitrosamine (DEN)-induced mouse HCC tissues and that periostin knockout impairs DEN-induced HCC development. Periostin is predominantly derived from activated HSCs and periostin deficiency in HSCs impairs HSC activation and inhibits HSC-promoted HCC cell proliferation in vitro and tumor growth in vivo. Mechanistically, periostin promotes HSC activation through the integrin-FAK-STAT3-periostin pathway and augments HCC cell proliferation by activating ERK. There are positive correlations between periostin and HSC activation and cell proliferation in HCC clinical samples. Collectively, our findings demonstrate that HSC-derived periostin promotes HCC development by enhancing HSC activation through an autocrine periostin-integrin-FAK-STAT3-periostin circuit and by augmenting HCC cell proliferation via the ERK pathway in a paracrine manner. Thus, periostin is a multifaceted extracellular regulator in the development of HCC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Acute Myeloid Leukemia Mutations and Future Mechanistic Target to Overcome Resistance

OPINION STATEMENT

Cytogenetics and mutation identification in acute myeloid leukemia have allowed for more targeted therapy. Many therapies have been approved by the FDA in the last 3 years including gilteritinib and azacitidine but the overall survival has remained stagnant at 25%. The inability to achieve complete remission was related to the residual leukemic stem cells (LSCs). Thus, the relationship between bone marrow niche and LSCs must be further explored to prevent treatment relapse/resistance. The development of immunotherapy and nanotechnology may play a role in future therapy to achieve the complete remission. Nano-encapsulation of drugs can improve drugs' bioavailability, help drugs evade resistance, and provide combination therapy directly to the cancer cells. Studies indicate targeting surface antigens such as CLL1 and CD123 using chimeric antibody receptor T cells can improve survival outcomes. Finally, new discoveries indicate that inhibiting integrin αvβ3 and acid ceramidase may prove to be efficacious.

METTL3/METTL14 Transactivation and m6A-Dependent TGF-β1 Translation in Activated Kupffer Cells

BACKGROUND AND AIMS

Transforming growth factor β1 (TGF-β1) secreted from activated Kupffer cells (KC) promotes the progression of nonalcoholic steatohepatitis (NASH) to liver fibrosis. N6-methyladenosine (m⁶A) RNA modification participates in various cell stress responses, yet it remains unknown whether it plays a role in TGF-β1 upregulation in activated KCs.

METHODS

Western blot, dot blot, and liquid chromatography with tandem mass spectrometry were used to determine the expression of m⁶A methyltransferase, METTL3, and METTL14, as well as global m⁶A modification. RNA-sequencing and m⁶A-seq were employed to screen differentially expressed genes and responsive m⁶A peaks. Nuclear factor κB (NF-κB)-mediated METTL3/METTL14 transactivation were validated with chromatin immunoprecipitation polymerase chain reaction and dual-luciferase reporter system, and the role of m⁶A in TGF-β1 upregulation was further verified in METTL3/METTL14-deficient KCs and myeloid lineage cell-specific METTL14 knockout mice.

RESULTS

Serum lipopolysaccharide (LPS) concentration is increased in high-fat diet-induced NASH rats. TGF-β1 upregulation is closely associated with METTL3/METTL14 upregulation and global m⁶A hypermethylation, in both NASH rat liver and LPS-activated KCs. LPS-responsive m⁶A peaks are identified on the 5' untranslated region (UTR) of TGF-β1 messenger RNA (mRNA). NF-κB directly transactivates METTL3 and METTL14 genes. LPS-stimulated TGF-β1 expression is abolished in METTL3/METTL14-deficient KCs and myeloid lineage cell-specific METTL14 knockout mice. Mutation of m⁶A sites on the 5'UTR of TGF-β1 mRNA blocks LPS-induced increase of luciferase reporter activity.

CONCLUSIONS

NF-κB acts as transcription factor to transactivate METTL3/METTL14 genes upon LPS challenge, leading to global RNA m⁶A hypermethylation. Increased m⁶A on the 5'UTR of TGF-β1 mRNA results in m⁶A-dependent translation of TGF-β1 mRNA in a cap-independent manner. We identify a novel role of m⁶A modification in TGF-β1 upregulation, which helps to shed light on the molecular mechanism of NASH progression.

Upregulated microRNA-132 in T helper 17 cells activates hepatic stellate cells to promote hepatocellular carcinoma cell migration in vitro

MicroRNAs play an important role in the modulation of the immune system. T helper 17 (Th17) cells are involved in the modulation of the tumour microenvironment. However, the function of miRNA in Th17 cells in the tumour microenvironment is unclear. In this study, we analysed miR-132 expression in Th17 cells and assessed the function of miR-132 on Th17 cell differentiation. In addition, the effect of miR-132 on Th17 cells in the tumour microenvironment, especially hepatic stellate cells (HSCs), was confirmed. CD4+ IL-17 ∓ cells were isolated from hepatocellular carcinoma (HCC) tumour tissues. The expression of miR-132 was higher in CD4+ IL-17 + cells than in CD4+ IL-17- cells. Human primary CD4+ T cells were used for Th17 cell differentiation. Compared with primary CD4+ T cells, Th17 cells expressed high levels of miR-132. During Th17 cell differentiation, a miR-132 mimic and inhibition were applied. After treatment with the miR-132 mimic, the differentiation of Th17 cells accelerated, showing a a higher percentage of Th17 cells and the expression and secretion of IL-17 and IL-22. Smad nuclear interacting protein 1 (SNIP1), as one of the targets of miR-132, decreased during Th17 cell differentiation-related Th17 differentiation and IL-17 expression. The conditioned medium of miR-132-overexpressing Th17 cells could increase the activation of the HSCs, which strongly promoted HCC cell migration and epithelial-mesenchymal transition (EMT). In summary, miR-132 positively regulates Th17 cell differentiation and improves the function of Th17 on HSCs for their tumour-promoting effects.

Nanotechnology Based Approach for Hepatocellular Carcinoma Targeting

Hepatocellular carcinoma (HCC) is the primary liver cancer that has shown a high incidence and mortality rate worldwide among several types of cancers. A large variety of chemotherapeutic agents employed for the treatment have a limited success rate owing to their limited site-specific drug targeting ability. Thus, there is a demand to develop novel approaches for the treatment of HCC. With advancements in nanotechnology-based drug delivery approaches, the challenges of conventional chemotherapy have been continuously decreasing. Nanomedicines constituted of lipidic and polymeric composites provide a better platform for delivering and opening new pathways for HCC treatment. A score of nanocarriers such as surface-engineered liposomes, nanoparticles, nanotubes, micelles, quantum dots, etc., has been investigated in the treatment of HCC. These nanocarriers are considered to be highly effective clinically for delivering chemotherapeutic drugs with high site-specificity ability and therapeutic efficiency. The present review highlights the current focus on the application of nanocarrier systems using various ligand-based receptor-specific targeting strategies for the treatment and management of HCC. Moreover, the article has also included information on the current clinically approved drug therapy for hepatocellular carcinoma treatment and updates of regulatory requirements for approval of such nanomedicines.

Co-Delivery of Curcumin and Capsaicin by Dual-Targeting Liposomes for Inhibition of aHSC-Induced Drug Resistance and Metastasis

Recent research studies have shown that the low survival rate of liver cancer is due to drug resistance and metastasis. In the tumor microenvironment (TME), activated hepatic stellate cells (aHSCs) have been proven to favor the development of liver cancer. Hence, the combination therapy dual-targeting aHSCs and tumor cells might be an effective strategy for treatment of liver cancer. In this study, the novel multifunctional liposomes (CAPS-CUR/GA&Gal-Lip) were prepared for co-delivery of curcumin (CUR) and capsaicin (CAPS), in which glycyrrhetinic acid (GA) and galactose (Gal) were chosen as targeting ligands to modify the liposomes (Lip) for dual-targeting liver cancer. To mimic TME, a novel HSCs+HepG2 (human hepatoma cell line) cocultured model was established for the antitumor effect in vitro. The results showed that, compared to HepG2 cells alone, the cocultured model promoted drug resistance and migration by upregulating the expression of P-glycoprotein (P-gp) and Vimentin, which were effectively inhibited by CAPS-CUR/GA&Gal-Lip. The efficacy of the in vivo antitumor was evaluated by three mice models: subcutaneous H22 (mouse hepatoma cell line) tumor-bearing mice, H22+m-HSC (mouse hepatic stellate cell) tumor-bearing mice, and orthotopic H22 cells-bearing mice. The results showed that CAPS-CUR/GA&Gal-Lip exhibited lesser extracellular matrix (ECM) deposition, lesser tumor angiogenesis, and superior antitumor effect compared with the no- and/or Gal-modified Lip, which was attributed to the simultaneous blocking of the activation of HSCs and inhibition of the metastasis of tumor cells. The dual-targeting method using Lip is thus a potential strategy for liver cancer treatment.

Sulfatase 2-Induced Cancer-Associated Fibroblasts Promote Hepatocellular Carcinoma Progression via Inhibition of Apoptosis and Induction of Epithelial-to-Mesenchymal Transition

Background

Sulfatase 2 (SULF2) removes the 6-O-sulfate groups from heparan sulfate proteoglycans (HSPG) and consequently alters the binding sites for various signaling molecules. Here, we elucidated the role of SULF2 in the differentiation of hepatic stellate cells (HSCs) into carcinoma-associated fibroblasts (CAFs) in the hepatocellular carcinoma (HCC) microenvironment and the mechanism underlying CAF-mediated HCC growth.

Methods

The clinical relevance of SULF2 and CAFs was examined using in silico and immunohistochemical (IHC) analyses. Functional studies were performed to evaluate the role of SULF2 in the differentiation of HSCs into CAFs and elucidate the mechanism underlying CAF-mediated HCC growth. Mechanistic studies were performed using the chromatin immunoprecipitation, luciferase reporter, and RNA immunoprecipitation assays. The in vitro findings were verified using the nude HCC xenograft mouse model.

Results

The Cancer Genome Atlas (TCGA) database and IHC analyses revealed that the expression of CAF markers, which was positively correlated with that of SULF2 in the HCC tissues, predicted unfavorable postsurgical outcomes. Co-culturing HSCs with HCC cells expressing SULF2 promoted CAF differentiation. Additionally, CAFs repressed HCC cell apoptosis by activating the SDF-1/CXCR4/PI3K/AKT signaling pathway. Meanwhile, SULF2-induced CAFs promoted epithelial-to-mesenchymal transition (EMT) of HCC cells by modulating the SDF-1/CXCR4/OIP5-AS1/miR-153-3p/SNAI1 axis. Studies using HCC xenograft mouse models demonstrated that OIP5-AS1 induced EMT by upregulating SNAI1 and promoted HCC growth in vivo.

Conclusion

These data indicated that SULF2 secreted by the HCC cells induced the differentiation of HSCs into CAFs through the TGFβ1/SMAD3 signaling pathway. SULF2-induced CAFs attenuated HCC apoptosis by activating the SDF-1/CXCR4/PI3K/AKT signaling pathway and induced EMT through the SDF-1/CXCR4/OIP5-AS1/miR-153-3p/SNAI1 axis. This study revealed a novel mechanism involved in the crosstalk between HCC cells and CAFs in the tumor microenvironment, which can aid in the development of novel and efficient therapeutic strategies for primary liver cancer.

Hepatic stellate cells - from past till present: morphology, human markers, human cell lines, behavior in normal and liver pathology

Hepatic stellate cell (HSC), initially analyzed by von Kupffer, in 1876, revealed to be an extraordinary mesenchymal cell, essential for both hepatocellular function and lesions, being the hallmark of hepatic fibrogenesis and carcinogenesis. Apart from their implications in hepatic injury, HSCs play a vital role in liver development and regeneration, xenobiotic response, intermediate metabolism, and regulation of immune response. In this review, we discuss the current state of knowledge regarding HSCs morphology, human HSCs markers and human HSC cell lines. We also summarize the latest findings concerning their roles in normal and liver pathology, focusing on their impact in fibrogenesis, chronic viral hepatitis and liver tumors.

Discovery of antiproliferative and anti-FAK inhibitory activity of 1,2,4-triazole derivatives containing acetamido carboxylic acid skeleton

Small molecule inhibitors of the focal adhesion kinase are regarded as promising tools in our armamentarium for treating cancer. Here, we identified four 1,2,4-triazole derivatives that inhibit FAK kinase significantly and evaluated their therapeutic potential. Most tested compounds revealed potent antiproliferative activity in HepG2 and Hep3B liver cancer cells, in which 3c and 3d were the most potent (IC₅₀ range; 2.88 ~ 4.83 µM). Compound 3d possessed significant FAK inhibitory activity with IC₅₀ value of 18.10 nM better than the reference GSK-2256098 (IC₅₀ = 22.14 nM). The preliminary mechanism investigation by Western blot analysis showed that both 3c and 3d repressed FAK phosphorylation comparable to GSK-2256098 in HepG2 cells. As a result of FAK inhibition, 3c and 3d inhibited the pro-survival pathways by decreasing the phosphorylation levels of PI3K, Akt, JNK, and STAT3 proteins. This effect led to apoptosis induction and cell cycle arrest. Taken together, these results indicate that 3d could serve as a potent preclinical candidate for the treatment of cancers.

Ubiquitin-proteasome system-targeted therapy for uveal melanoma: what is the evidence?

Uveal melanoma (UM) is a rare ocular tumor. The loss of BRCA1-associated protein 1 (BAP1) and the aberrant activation of G protein subunit alpha q (GNAQ)/G protein subunit alpha 11 (GNA11) contribute to the frequent metastasis of UM. Thus far, limited molecular-targeted therapies have been developed for the clinical treatment of UM. However, an increasing number of studies have revealed the close relationship between the ubiquitin proteasome system (UPS) and the malignancy of UM. UPS consists of a three-enzyme cascade, i.e. ubiquitin-activating enzymes (E1s); ubiquitin-conjugating enzymes (E2s); and ubiquitin-protein ligases (E3s), as well as 26S proteasome and deubiquitinases (DUBs), which work coordinately to dictate the fate of intracellular proteins through regulating ubiquitination, thus influencing cell viability. Due to the critical role of UPS in tumors, we here provide an overview of the crosstalk between UPS and the malignancy of UM, discuss the current UPS-targeted therapies in UM and highlight its potential in developing novel regimens for UM.

The Biological Functions and Clinical Applications of Integrins in Cancers

Integrins are the adhesion molecules and receptors of extracellular matrix (ECM). They mediate the interactions between cells-cells and cells-ECM. The crosstalk between cancer cells and their microenvironment triggers a variety of critical signaling cues and promotes the malignant phenotype of cancer. As a type of transmembrane protein, integrin-mediated cell adhesion is essential in regulating various biological functions of cancer cells. Recent evidence has shown that integrins present on tumor cells or tumor-associated stromal cells are involved in ECM remodeling, and as mechanotransducers sensing changes in the biophysical properties of the ECM, which contribute to cancer metastasis, stemness and drug resistance. In this review, we outline the mechanism of integrin-mediated effects on biological changes of cancers and highlight the current status of clinical treatments by targeting integrins.