Current and Future Treatment of Hepatocellular Carcinoma: An Updated Comprehensive Review

The Proanthocyanidin-Rich Fraction Obtained from Red Rice Germ and Bran Extract Induces HepG2 Hepatocellular Carcinoma Cell Apoptosis

This study aims to determine the anti-carcinogenic effects of the proanthocyanidin-rich fraction (PRFR) obtained from red rice germ and bran extract on HepG2 cells. The PRFR obtained from red rice germ and bran extract could reduce the cell viability of HepG2 cells as shown by the IC₅₀ value at 20 µg/mL. Notably, PRFR concentrations at 20 and 40 µg/mL significantly increased the number of cells in the G2/M phase from 25.7% ± 1.4%in the control group to 36.2% ± 3.4% (p < 0.01) and 48.9% ± 2.6% (p < 0.0001), respectively, suggesting that the cells were arrested in this phase, which was confirmed by the reduction of survival proteins, including cyclin B1 and cdc25. Moreover, the PRFR at 20 and 40 µg/mL could induce cell death via the apoptosis cascade, indicated by the percentage of total apoptotic cells from 9.9% ± 3.1% in the control group to 41.1 ± 3.9 (p < 0.0001) and 82.2% ± 5.8% (p < 0.0001), respectively. This was clarified by increasing apoptotic proteins (such as cleaved PARP-1, cleaved caspase-8 and cleaved caspase-3) and decreasing anti-apoptotic protein survivin without p53 alterations. These results demonstrated that the PRFR obtained from red rice germ and bran extract could inhibit cell proliferation and induce cell apoptosis in HepG2 cells via survivin, which could potentially serve as a new target for cancer therapeutics making it an excellent "lead candidate" molecule for in vivo proof-of concept studies.

[Effect of danusertib on cell cycle, apoptosis and autophagy of hepatocellular carcinoma HepG2 cells in vitro]

OBJECTIVE

To investigate the effect of danusertib (Danu), an inhibitor of Aurora kinase, on the proliferation, cell cycle, apoptosis, and autophagy of hepatocellular carcinoma HepG2 cells and explore the underlying mechanisms.

METHODS

MTT assay was used to examine the effect of Danu on the viability of HepG2 cells to determine the IC50 of Danu. The effect of Danu on cell cycle distribution, apoptosis and autophagy were determined using flow cytometry. Western blotting was used to detect the expressions of the proteins related to cell cycle, apoptosis and autophagy. Chloroquine was used to suppress Danuinduced autophagy to test the apoptosis-inducing effect of Danu.

RESULTS

Danu significantly inhibited the proliferation of HepG2 cells with IC₅₀ of 39.4 μmol and 14.4 μmol at 24 h and 48 h, respectively. Danu caused cell cycle arrest in G₂/M phase in HepG2 cells and led to polyploidy accumulation via up-regulating the expressions of p53 and p21 and down-regulating the expressions of cyclin B1 and DC2. Danu also caused apoptosis of HepG2 cells through up-regulating the expressions of Bax, Puma, cleaved caspase-3, cleaved caspase-9, cleaved PARP and cytochrome C and down-regulating the expressions of Bcl-xl and Bcl-2. Danu induced autophagy via activating AMPK signaling and inhibiting PI3K/PTEN/AKT/mTOR axis, and inhibition of Danu-induced autophagy with chloroquine enhanced the pro-apoptotic effect of Danu.

CONCLUSIONS

Danu inhibits cell proliferation and induces cell cycle arrest in G₂/M phase, apoptosis and cytoprotective autophagy in HepG2 cells.

Downregulation of protein disulfide‑isomerase A3 expression inhibits cell proliferation and induces apoptosis through STAT3 signaling in hepatocellular carcinoma

Protein disulfide‑isomerase A3 (PDIA3) is a chaperone protein that modulates folding of newly synthesized glycoproteins and responds to endoplasmic reticulum (ER) stress. Previous studies reported that increased expression of PDIA3 in hepatocellular carcinoma (HCC) is a marker for poor prognosis. However, the mechanism remains poorly understood. The aim of the present study, therefore, was to understand the role of PDIA3 in HCC development. First, immunohistochemical staining of tissues from 53 HCC cases revealed that HCC tissues with high PDIA3 expression exhibited a higher proliferation index and contained fewer apoptotic cells than those with low expression. In addition, the knockdown of PDIA3 significantly inhibited cell proliferation and induced apoptosis in HCC cell lines. These results suggest that PDIA3 regulates cell proliferation and apoptosis in HCC. An examination of whether PDIA3 knockdown induced apoptosis through ER stress revealed that PDIA3 knockdown did not increase ER stress marker, 78 kDa glucose‑regulated protein, in HCC cell lines. Furthermore, the association between PDIA3 and the signal transducer and activator of transcription 3 (STAT3) signaling pathway were investigated in vitro and in vivo. Immunofluorescence staining and co‑immunoprecipitation experiments revealed colocalization and binding, respectively, of PDIA3 and STAT3 in HCC cell lines. The knockdown of PDIA3 decreased the levels of phosphorylated STAT3 (P‑STAT3; Tyr705) and downstream proteins of the STAT3 signaling pathway: The anti‑apoptotic proteins (Bcl‑2‑like protein 1, induced myeloid leukemia cell differentiation protein Mcl‑1, survivin and X‑linked inhibitor of apoptosis protein). In addition, PDIA3 knockdown provided little inhibitory effect on cell proliferation in HCC cell lines treated with AG490, a tyrosine‑protein kinase JAK/STAT3 signaling inhibitor. Finally, an association was demonstrated between PDIA3 and P‑STAT3 expression following immunostaining of 35 HCC samples. Together, the present data suggest that PDIA3 promotes HCC progression through the STAT3 signaling pathway.

A 4-gene prognostic signature predicting survival in hepatocellular carcinoma

OBJECTIVE

To develop an independent prognostic signature for patients with hepatocellular carcinoma (HCC).

METHODS

HCC gene expression profile the cancer genome atlas-liver hepatocellular carcinoma and GSE14520 were used as discovery and test set, respectively. Differentially expressed genes (DEGs) were identified between HCC tissues and adjacent normal liver tissues. Univariate Cox proportional hazards regression analysis was performed to identify DEGs correlated with survival of HCC patients. A 4-gene-based signature was constructed based on a least absolute shrinkage and selection operator Cox penalized regression model. The predictive value of the signature was analyzed and validated.

RESULTS

Two hundred sixty-three DEGs were identified between HCC and adjacent liver tissues. After univariate survival analysis, 90 DEGs were found to be significantly correlated with the overall survival (OS) of HCC patients, of which 4 genes (KPNA2, CDC20, SPP1, and TOP2A) with non-zero coefficient were used to construct a prognostic signature. The 4-gene signature was significantly associated with the age (P = 0.046), grade ( P = 0.022), and T stage ( P = 0.023) of HCC patients in the discovery set and it also significantly associated with TNM stage ( P = 0.033), and serum alpha-fetoprotein lever ( P = 0.034). Patients in the 4-gene low-risk group were associated with better OS and recurrence-free survival (RFS) than those in the high-risk group in the discovery and test set. Meanwhile, the 4-gene signature is an independent prognostic factor regarding OS and RFS in the discovery and test set.

CONCLUSION

We developed a 4-gene-based signature, which could be a candidate prognostic factor for patients with HCC.

Staging systems of hepatocellular carcinoma: A review

Staging of hepatocellular carcinoma (HCC) is necessary for guiding prognostication, management, and research purposes that further aid in the improvement of existing clinical and epidemiological health services. Though there are some new staging systems for HCC developed in different parts of the world, there is no globally accepted staging system that allows for comparison of current management protocols among heterogeneous populations. In this review, we discuss the evolution and applicability in clinical practice of different clinical staging systems of HCC-Okuda, CLIP (Cancer of the Liver Italian Program) score, MESIAH (Model to Estimate Survival In Ambulatory HCC patients) score, ITA.LI.CA (Italian Liver Cancer) score, BCLC (Barcelona Clinic Liver Cancer) staging, HKLC (Hong Kong Liver Cancer) staging, and the Alberta algorithm. This review aims to highlight the main criteria for assessing the prognosis of HCC that these different staging systems take into account, their strengths and limitations for use in modern clinical practice. Despite the limitations of the BCLC staging system, it remains the most validated and reliable system for prognostication. However, there is a need to update the BCLC staging system to include recent data on locoregional and systemic therapies for HCC, expanded criteria for transplantation, and systemic therapy for hepatitis C infection.

Liquid biopsies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the world's second leading cause of cancer death; 82.4% of patients die within 5 years. This grim prognosis is the consequence of a lack of effective early detection tools, limited treatment options, and the high frequency of HCC recurrence. Advances in the field of liquid biopsy hold great promise in improving early detection of HCC, advancing patient prognosis, and ultimately increasing the survival rate. In an effort to address the current challenges of HCC screening and management, several studies have identified and evaluated liver-cancer-associated molecular signatures such as genetic alterations, methylation, and noncoding RNA expression in the form of circulating biomarkers in body fluids and circulating tumor cells of HCC patients. In this review, we summarize the recent progress in HCC liquid biopsy, organized by the intended clinical application of the reported study.

miR-122 enhances sensitivity of hepatocellular carcinoma to oxaliplatin via inhibiting MDR1 by targeting Wnt/β-catenin pathway

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the primary causes of cancer-related death and resistance to cytotoxic chemotherapy is the major cause of mortality in HCC patients. miR-122 is a liver specific miRNA and is found to be reduced in HCC, however, the function of miR-122 in HCC chemosensitivity remains elusive.

METHODS

We used qRT-PCR to measure expressions of miR-122, β-catenin and MDR1 in four HCC cell lines. And we assessed the effects of miR-122 or β-catenin on cell viability and apoptosis upon oxaliplatin (OXA) treatment by MTT assay and flow cytometry. In addition, we validated the interactions of miR-122/β-catenin and β-catenin/MDR1 by dual luciferase reporter assay and chromatin immunoprecipitation (ChIP). Western blotting was used to determine the protein levels of β-catenin, Wnt1 and MDR1. In the end, we verified the anti-tumor effect of miR-122 in vivo by using mouse tumor xenograft model.

RESULTS

We found that miR-122 was down-regulated in HCC cells. Up-regulation of miR-122 or inhibition of Wnt/β-catenin signaling promoted HCC cells apoptosis and increased the sensitivity of HCC cells to OXA. On the molecular level, we showed that miR-122 directly targeted and suppressed Wnt/β-catenin pathway while β-catenin bound with MDR1 promoter and activated its transcription. Overexpression of miR-122 inhibited MDR1 expression via directly suppressing Wnt/β-catenin pathway.

CONCLUSION

Our study fully demonstrated that miR-122 inhibits MDR1 expression via suppression of Wnt/β-catenin pathway, thereby enhancing HCC sensitivity to OXA. Therefore, miR-122 could serve as a novel potential therapeutic target for HCC.

Microvascular Invasion in HCC: The Molecular Imaging Perspective

Hepatocellular carcinoma represents the most frequent primary liver tumor; curative options are only surgical resection and liver transplantation. From 1996, Milan Criteria are applied in consideration of patients with cirrhosis and hepatocellular for liver transplantation; nonetheless, more recently, Milan Criteria have been criticized because they appear over conservative. Apart from number and size of lesions and biomarker levels, which already have been associated with poorer prognosis, overall survival and recurrence rates after transplantation are affected also by the presence of vascular invasion. Microvascular invasion suggests a poor prognosis but it is often hard to detect before transplant. Diagnostic imaging and tumor markers may play an important role and become the main tools to define microvascular invasion. In particular, a possible role could be found for computed tomography, magnetic resonance imaging, and positron emission tomography. In this paper, we analyze the possible role of positron emission tomography as a preoperative imaging biomarker capable of predicting microvascular invasion in patients with hepatocellular carcinoma and thus selecting optimal candidates for liver transplantation.

CCL20 is overexpressed in hepatocellular carcinoma with bile duct tumor thrombus and correlates negatively with surgical outcome

There is not yet a consensus regarding prognosis of hepatocellular carcinoma (HCC) with bile duct tumor thrombus (BDTT) versus without bile duct tumor thrombus. Chemokine (C-C motif) ligand 20 (CCL20) plays critical roles in the progress of many types of tumor. But the clinicopathological and prognostic value of this marker in HCC with BDTT is unceratin. In this study, we reported that the overall survival (OS) and disease-free survival (DFS) in HCC with BDTT were significantly shorter than in those without BDTT (P<0.05). CCL20 was expressed at a significantly higher level in bile duct tumor thrombus by real-time PCR, western blot, and immunohistochemistry. Patients with high CCL20 expression levels had a poor prognosis. Multivariate survival analysis indicated that CCL20 was an independent prognostic factor for OS. The presence of bile duct tumor thrombus indicateda poor prognosis in HCC patients, but was not a surgical contraindication. CCL20 was associated with tumor progression and high CCL20 expression was correlated with worse surgical outcomes in HCC with BDTT. Inhibition of CCL20 expression might offer novel promising molecular targets for treatment.

Elevated CTSL2 expression is associated with an adverse prognosis in hepatocellular carcinoma

OBJECTIVE

Cathepsin V, also known as CTSL2, plays an important role in tumor development and progression. This study was designed to investigate the clinical significance of CTSL2 expression in hepatocellular carcinoma (HCC) and the relationship between CTSL2 expression and prognosis.

METHODS

Quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were performed to determine the levels of CTSL2 mRNA and protein, respectively, in tumor tissue and matched non-tumor (NT) tissue. Moreover, the relationship between CTSL2 expression and hepatocellular carcinoma's clinicopathological features and survival was evaluated in HCC tissue.

RESULTS

The levels of CTSL2 mRNA and protein were increased in HCC tissue. Moreover, for HCC patients, a high level of CTSL2 protein was significantly correlated with tumor number (P = 0.008), pathological grade (P = 0.001), vascular invasion (P = 0.001), T (P = 0.001), and TNM stage (P = 0.006). A Kaplan-Meier analysis showed that elevated CTSL2 expression was correlated with shorter disease-free survival (DFS) (P < 0.001) and overall survival (OS) (P < 0.001). Furthermore, a multivariate analysis showed that CTSL2 expression was an independent prognostic factor for DFS (P = 0.032) and OS (P = 0.025).

CONCLUSION

This study showed that abnormal CTSL2 expression may contribute to HCC progression and that elevated CTSL2 expression is associated with an adverse prognosis in HCC.