TGF-β1/SMAD3-driven GLI2 isoform expression contributes to aggressive phenotypes of hepatocellular carcinoma

Hedgehog signaling is activated in response to liver injury, and modulates organogenesis. However, the role of non-canonical hedgehog activation via TGF-β1/SMAD3 in hepatic carcinogenesis is poorly understood. TGF-β1/SMAD3-mediated non-canonical activation was found in approximately half of GLI2-positive hepatocellular carcinoma (HCC), and two new GLI2 isoforms with transactivating activity were identified. Phospho-SMAD3 interacted with active GLI2 isoforms to transactivate downstream genes in modulation of stemness, epithelial-mesenchymal transition, chemo-resistance and metastasis in poorly-differentiated hepatoma cells. Non-canonical activation of hedgehog signaling was confirmed in a transgenic HBV-associated HCC mouse model. Inhibition of TGF-β/SMAD3 signaling reduced lung metastasis in a mouse in situ hepatic xenograft model. In another cohort of 55 HCC patients, subjects with high GLI2 expression had a shorter disease-free survival than those with low expression. Moreover, co-positivity of GLI2 with SMAD3 was observed in 87.5% of relapsed HCC patients with high GLI2 expression, indicating an increased risk of post-resection recurrence of HCC. The findings underscore that suppressing the non-canonical hedgehog signaling pathway may confer a potential strategy in the treatment of HCC.

Genome-wide long noncoding RNA and mRNA expression profiles demonstrate associations between exposure to inorganic elements and the risk of developing hepatocellular carcinoma

Background

Long noncoding RNAs (lncRNAs) are closely associated with the development of hepatocellular carcinoma (HCC). The present study conducted a genome-wide microarray analysis and qPCR validation to obtain comprehensive insights into this issue.

Methods

Thirty male HCC patients with chronic HBV infection were included in the present study. Primary HCC tissue and normal tissue were collected. Double-stranded complementary DNA synthesized from 10 pairs of samples was labeled and hybridized to a microarray chip. Further analyses, such as hierarchical clustering, gene ontology (GO) and pathway analyses, were performed. In addition, qPCR validation was performed on tissue samples and additional serum samples.

Results

The microarray analysis identified 946 upregulated and 571 downregulated lncRNAs and 1720 upregulated and 1106 downregulated mRNAs. Among these RNAs, ENST00000583827.1 (fold change: 21) and uc010isf.1 (fold change: 18) were the most over- and underexpressed lncRNAs in the HCC tissues, respectively. For the mRNAs, KIF20A (fold change: 26) and HEPACAM (fold change: 50) were the most over- and underexpressed in the HCC tissues, respectively. The GO analysis demonstrated that the most differentially expressed mRNAs were related to the response of metal ions. The pathway analysis also suggested that the most enriched pathway was mineral absorption.

Conclusions

The subsequent qPCR validation exhibited high consistency with the microarray analysis, except for three lncRNAs. The qPCR analysis also demonstrated that TCONS_00008984 had a 767-fold overexpression level in HCC tissues when compared with normal tissues, and this finding was confirmed in the serum samples; therefore, TCONS_00008984 has the potential to serve as a diagnostic marker or prognostic indicator. The GO and pathway analyses indicated that exposure to inorganic elements may be involved in HCC risk.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-021-00927-w.

Identification of mTOR as a primary resistance factor of the IAP antagonist AT406 in hepatocellular carcinoma cells

Dysregulation of inhibitor of apoptosis (IAP) proteins (IAPs) in hepatocellular carcinoma (HCC) is often associated with poor prognosis. Here we showed that AT406, an IAP antagonist, was cytotoxic and pro-apoptotic to both established (HepG2, SMMC-7721 lines) and primary HCC cells. Activation of mTOR could be a key resistance factor of AT406 in HCC cells. mTOR inhibition (by OSI-027), kinase-dead mutation or knockdown remarkably enhanced AT406-induced lethality in HCC cells. Reversely, forced-activation of mTOR by adding SC79 or exogenous expressing a constitutively active S6K1 (T389E) attenuated AT406-induced cytotoxicity against HCC cells. We showed that AT406 induced degradation of IAPs (cIAP-1 and XIAP), but didn't affect another anti-apoptosis protein Mcl-1. Co-treatment of OSI-027 caused simultaneous Mcl-1 downregulation to overcome AT406's resistance. Significantly, shRNA knockdown of Mcl-1 remarkably facilitated AT406-induced apoptosis in HCC cells. In vivo, AT406 oral administration suppressed HepG2 tumor growth in nude mice. Its activity was potentiated with co-administration of OSI-027. We conclude that mTOR could be a key resistance factor of AT406 in HCC cells.

Chloride intracellular channel 1 is overexpression in hepatic tumor and correlates with a poor prognosis

Chloride intracellular channel 1 (CLIC1) is expressed in many human tissues and has been reported to be involved in the regulation of cell cycle, cell proliferation, and differentiation. Its roles in human hepatic tumor, however, remain unclear. The aim of this study was to investigate the clinicopathological significance and expression pattern of CLIC1 in human primary hepatic tumors. We examined the expression pattern of CLIC1 mRNA and protein in hepatic tumors using real-time quantitative RT-PCR and Western blot, respectively. CLIC1 protein and mRNA levels were significantly higher in cancerous tissues compared with corresponding normal tissue. In 85 hepatic tumor tissues, CLIC1 was significantly higher in 69 cases (81.2%), as determined by immunohistochemical staining. Increased CLIC1 expression was correlated with tumor size (p = 0.021), distant metastasis (p = 0.025), pathological TNM (pTNM) stage (p = 0.023), and poor survival (25.11 ± 2.27 vs 45.29 ± 4.28 months, p = 0.001). Our data show that increased CLIC1 protein expression is associated with clinicopathological factors and a poor prognosis of hepatic tumors, and suggest that CLIC1 might represent a valuable prognostic marker for human hepatic tumors.

Abstract 4726: Phagocytic regulation through exogenous caffeine exposure in whole-blood macrophages

Caffeine is the most widely used neurostimulant in the world, and it has been shown that 79% of the United States population drinks coffee at least occasionally. Previous research has suggested that caffeine may be involved in the regulation of phagocytosis in immune cells through anti-inflammatory and pro-inflammatory signals. To investigate this effect, we used a macrophage engulfment assay, which was optimized in our lab to measure phagocytosis after exogenous caffeine exposure. Human leukocytes were isolated and incubated to allow for monocyte differentiation. After being allowed to differentiate for 1hr, 24hrs, 3-days, or 7-days, macrophages were incubated with varying concentrations of caffeine (35 μM-20 mM) for 1-24 hours. Cells were treated with lipopolysaccharide, and then incubated for 2 hours with fluorescently-labeled microspheres conditioned by incubation with fetal bovine serum. Engulfment was measured using flow cytometry, indicating the phagocytosis of microspheres in integral ratios. It was observed that engulfment was dependent on cell differentiation time, as well as caffeine concentration and exposure time. After <12 hour differentiation, cells exposed to caffeine showed a concentration-dependent reduction in engulfment when compared to those that were not treated. During incubation for 12 - 72 hours, however, results showed a 20% down-regulation of engulfment at <5 mM caffeine, whereas those cells exposed to 5-10 mM caffeine exhibited a 20% higher-engulfing phenotype, compared to the controls. At caffeine concentrations above 10 mM cell viability and engulfment was decreased up to 50%. It was concluded that the effect of caffeine on macrophages is dependent on incubation time and concentration, as well as the state of macrophage differentiation. Because of the implications of macrophage phenotype in many diseases involving inflammation, including cancer, these findings suggest further research should be continued to explore the therapeutic potential of caffeine and/or its analogs.

Citation Format: Ryan Steck, Marcus Gustafsson, PingGuo Liu, Atif Elnaggar, Richard A. Robison, Kim L. O'Neill. Phagocytic regulation through exogenous caffeine exposure in whole-blood macrophages. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4726. doi:10.1158/1538-7445.AM2013-4726

Influence of mutations in hepatitis B virus surface protein on viral antigenicity and phenotype in occult HBV strains from blood donors

BACKGROUND & AIMS

This study aimed at investigating mutations in the hepatitis B surface protein (HBsAg) in occult hepatitis B virus (HBV) infection (OBI) and their influence on viral antigenicity and phenotype.

METHODS

The characteristics of 61 carriers with OBI (OBI group), 153 HBsAg(+) carriers with serum HBsAg ≤ 100 IU/ml (HBsAg-L group) and 54 carriers with serum HBsAg >100 IU/ml (HBsAg-H group) from 38,499 blood donors were investigated. Mutations in the major hydrophilic region (MHR) of the viral sequences were determined. Thirteen representative MHR mutations observed in OBI sequences were antigenically characterized with a panel of monoclonal antibodies (MAbs) and commercial HBsAg immunoassays and functionally characterized in HuH7 cells and hydrodynamically injected mice.

RESULTS

Of 61 OBI sequences, 34 (55.7%) harbored MHR mutations, which was significantly higher than the frequency in either the HBsAg-L (34.0%, p=0.003) or the HBsAg-H group (17.1%, p<0.001). Alterations in antigenicity induced by the 13 representative MHR mutations identified in the OBI group were assessed by reacting recombinant HBV mutants with 30 different MAbs targeting various epitopes. Four out of the 13 mutations (C124R, C124Y, K141E, and D144A) strongly decreased the analytical sensitivity of seven commercial HBsAg immunoassays, and 10 (G119R, C124Y, I126S, Q129R, S136P, C139R, T140I, K141E, D144A, and G145R) significantly impaired virion and/or S protein secretion in both HuH7 cells and mice.

CONCLUSIONS

MHR mutations alter antigenicity and impair virion secretion, both of which may contribute to HBsAg detection failure in individuals with OBI.

Clinical significance and expression of cyclin kinase subunits 1 and 2 in hepatocellular carcinoma

BACKGROUND

The mammalian cyclin kinase subunit (Cks) family has two members, Cks1 and Cks2, which were identified based on the protein sequence homology to yeast Cks. Overexpression of Cks1 and Cks2 has been reported to be associated with high aggressiveness and a poor prognosis in various malignancies, including gastric, breast and prostate carcinomas. Yet, whether Cks1 and Cks2 are overexpressed in hepatocellular carcinoma (HCC) remains uncharacterized.

AIMS

To investigate whether overexpression of the Cks family is clinically relevant to HCC, and whether expression patterns of Cks1 and Cks2 in HCC have diagnostic and prognostic value.

METHODS

Real-time quantitative reverse transcriptase polymerase chain reaction, immunostaining and Western blot analyses were used to detect the expression of Cks1 and Cks2 at the mRNA and protein levels respectively. The associations between Cks1 and Cks2 expressions and clinical features, as well as the association between Cks1 or Cks2 and p27(kip1) expressions in HCC, were analysed.

RESULTS

Expressions of Cks1 and Cks2 at both mRNA and protein levels were significantly higher in HCC than those in the adjacent noncancerous tissues (including chronic hepatitis and cirrhosis) and normal liver tissues. Overexpressions of Cks1 and Cks2 in HCC were closely associated with poor differentiation features. The expressions of both Cks1 and Cks2 were negatively associated with p27(kip1) at the protein level.

CONCLUSIONS

Overexpression of Cks1 and Cks2 is associated with the aggressive tumour behaviours of HCC, and thus has diagnostic and prognostic value. Further efforts are needed to develop novel biomarkers for HCC based on CKs1 and Cks2 expressions.

Effect of EGCG on expression of TGF-β1 and CTGF in rats with liver fibrosis

AIM: To examine the protective effects of epigallocatechin-3-gallate (EGCG) on CCl₄-induced hepatic fibrosis.

METHODS: A rat model of CCl₄-induced hepatic fibrosis was established to assess the effect of EGCG on the treatment for fibrosis. Liver fibrosis of the rats was evaluated by two histological methods: HE staining and Masson's trichrome staining. Activities of serum ALT and AST were checked with automated biochemistry analyzer. The levels of liver tissue hydroxyproline, glutathione (GSH) and thiobarbituratic acid reactive substances (TBARS) were also determined. The expression of α-SMA in hepatic tissue was detected by immunohistochemistry. The mRNA and protein levels of TGF-β1 and CTGF expression were detected by RT-PCR and Western blot analysis.

RESULTS: Histological and hepatic hydroxyproline examination revealed that EGCG significantly arrested progression of hepatic fibrosis. EGCG caused significant amelioration of liver injury, and reduced activities of serum ALT and AST (138.4 ± 45.8 vs 234.6 ± 63.2, 96.4 ± 20.5 vs 186.2 ± 36.6, both P < 0.05). Redox state was improved in CCl₄-induced hepatic fibrosis through treatment with EGCG, by suppressing the TBARS formation and increasing the level of GSH. Moreover, EGCG markedly reduced both mRNA and protein expression of TGF-β1 and CTGF in the liver tissue (P < 0.05).

CONCLUSION: EGCG significantly arrested progression of hepatic fibrosis. The underlying mechanism was associated with changes in the redox state and markedly decreased expression of TGF and CTGF in liver tissue.

Protective effects of apocynin and allopurinol on ischemia/reperfusion-induced liver injury in mice

AIM: To determine the effects of allopurinol, an inhibitor of xanthine oxidase, and apocynin, an inhibitor of NADPH oxidase, on oxidant stress and liver injury caused by hepatic ischemia/reperfusion (I/R) procedure in mice.

METHODS: Mice were pretreated with a xanthine oxidase inhibitor, allopurinol, or NADPH oxidase (NOX) inhibitor, apocynin before the hepatic I/R procedure. Then treated or untreated mice underwent the hepatic I/R procedure. The effects on hepatic injury and superoxide anions were determined after starting reperfusion.

RESULTS: A standard warm hepatic I/R procedure led to a marked increase in superoxide anion production as indicated by a superoxide anion tracer, MCLA. At the same time, the procedure caused profound acute liver injury, as indicated by elevated serum alanine aminotransferase and tumor necrosis factor-α levels, reduced liver glutathione levels and elevated malondialdehyde contents, as well as a high apoptotic cell count. All these changes were reversed by the use of apocynin or allopurinol prior to the hepatic I/R procedure.

CONCLUSION: Allopurinol and apocynin exerted protective effects on hepatic ischemia/reperfusion injury. The protection is associated with blocking the generation of superoxide anions during the hepatic I/R procedure by inhibiting xanthine oxidase and NADPH oxidase activity.

Cloning and identification of human hepatocellular carcinoma-related genes

AIM: To clone and identify the differentially expressed gene fragments in hepatocellular carcinoma (HCC) and normal liver tissues and to explore the molecular pathogenesis of HCC.

METHODS: Fluorescent mRNA differential display (mRNA-DD) was used to compare the differential gene expression in HCC and normal liver tissue samples. The obtained gene fragments were cloned and sequenced. The sequences were submitted to the GenBank for homologue analysis using BLAST software. RT-PCR was performed to detect the expression of each differential gene fragment in HCC and normal tissue samples.

RESULTS: Gel imaging scan revealed a 500-600 bp differential gene fragment. The sequence of this gene fragment was compared with that in GenBank, showing that this gene fragment was homologous to EEG1 (99%). RT-PCR demonstrated that the expression of this gene fragment was significantly lower in HCC tissue samples than in normal tissue samples (P = 0.001).

CONCLUSION: EEG1 gene expression is much lower in HCC tissue than in normal tissue. Its down-regulated expression in HCC tissues is probably related to the carcinogenesis of HCC.

Preventive effect of regional radiotherapy with phosphorus-32 glass microspheres in hepatocellular carcinoma recurrence after hepatectomy

AIM: To evaluate the preventive effects of phosphorus-32 glass microspheres (P³²-GMS) in the recurrence of massive hepatocellular carcinomas (HCCs) after tumor resection.

METHODS: Twenty-nine patients with massive HCCs received local P³²-GMS implantation after liver tumors were removed, while the other 38 patients with massive HCCs were not treated with P³²-GMS after hepatectomies. The radioactivity of the blood, urine and liver were examined. The complications, HCC recurrence and overall survival rates in the patients were analyzed.

RESULTS: P³²-GMS implanted in the liver did not cause systemic absorption of P³². There were no significant differences of postoperative complications between the patients with and without P³²-GMS treatment. The short-term (six months and 1 year) and long-term (2, 3 and over 3 years) recurrence rates in patients who received P³²-GMS radiotherapy were significantly decreased, and the overall survival rates in this group were significantly improved.

CONCLUSION: P³²-GMS implantation in the liver can significantly decrease the postoperative recurrence and improve the overall survival in HCCs patients after hepatectomy. This therapy may provide an innovative method in prevention of HCC recurrence after operation.

[Left ventricular end-systolic pressure-dimension relation and its sensitility to the positive inotropic factor in the anesthetized open-chest dogs]

Left ventricular end-systolic pressure-dimension relation (ESPDR) was generated by the transient occlusion of the inferior vena cava (IVC) or thoracic aorta (AO) in 13 anesthetized open-chest dogs, while the left ventricular pressure was measured by a TP-200T pressure transducer and the anterior-posterior dimension was measured by a pair of ultrasonic crystal implanted in the endocardium and recorded by a Sonomicrometer. The results showed that: (1) the ESPDR was shown to be linear, unaltered by preload or afterload changes; (2) dobutamine produced a significant increase in the slope (Emax) of the ESPDR-IVC and ESPDR-AO relations, without remarkable effect on the dimension-axis intercept (Do). However, the change in Emax was more significant for ESPDR-IVC (174.43 +/- 23.48%, n = 18), as compared with that for the ESPDR-AO (71.02 +/- 12.46%, n = 12); (3) Do of the ESPDR-AO relation was smaller than that of the ESPDR-IVC both under control and during dobulamine infusion. We conclude that the linear ESPDR can be derived in the anesthetized open-chest dogs either by caval occlusion or by aortic occlusion, and the slope appears to reflect left ventricular contractility. However, techniques used to generate the ESPDR may influence results, including the Do and the sensitivity of Emax to the inotropic state.

Trousseau's syndrome in the head and neck

Thromboses in Trousseau's syndrome are typically confined to the vascular system of the extremities and viscera. The authors report a case of sequential bilateral internal and external jugular-vein thromboses secondary to this paraneoplastic hypercoagulable state. The etiologies of commonly encountered head and neck venous thromboses are infection, trauma, and obstruction. This article purports that head and neck venous thromboses without a proximal inflammatory or mechanical cause may be the initial manifestation of an occult malignancy. Upon establishing the presence of a hypercoagulable state, further evaluation may lead to the early diagnosis of such an occult malignancy.

Cervical abscess caused by Salmonella infection

A 69-year-old man had an abscess in the neck caused by Salmonella hador (enteritidis) infection. Salmonella infection of the head and neck are rare, and often occur in association with Salmonella infection in other parts of the body. The patient described may have had seeding to the neck from previous gastrointestinal infection. Treatment by drainage of the abscess and oral administration of ampicillin was successful. To the authors' knowledge, this is the sixth case of pure Salmonella infection of the head and neck reported in the world literature.