CD117 (c-kit) expression in human hepatocellular carcinoma

Adjuvant therapy with toceranib for hepatocellular carcinoma and cholangiocarcinoma in a Pomeranian

A 10-year-old spayed female Pomeranian dog was referred for hepatic mass evaluation. Blood tests revealed mildly elevated alkaline phosphatase activities. Computed tomography revealed a mass with multiple nodules on the right hepatic medial lobe adjacent to the caudal vena cava; histopathology confirmed mixed hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). Because of incomplete resection, adjuvant therapy was recommended. As tumour cells showed PDGFR-α, c-Kit, and FGFR1 overexpression, the anticancer effect of tyrosine kinase inhibitors was evaluated on the cells; toceranib was the most effective and was administered starting with an extra-labelled dose. The dog remained stable for 2.3 years with mild adverse effects. To our knowledge, this is the first successful clinical application of toceranib in a dog with mixed HCC-CC.

C-Kit, a Double-Edged Sword in Liver Regeneration and Diseases

Previous studies have reported an important role of c-kit in embryogenesis and adulthood. Activation of the SCF/KIT signal transduction pathway is customarily linked to cell proliferation, migration and survival thus influence hematopoiesis, pigmentation, and spermatogenesis. The role of c-kit in the liver is controversial, it is however argued that it is a double-edged sword in liver regeneration and diseases. First, liver c-kit⁺ cells, including oval cells, bile epithelial cells, and part of hepatocytes, participate in liver tissue repair by regenerating target cells according to the type of liver injury. At the same time, c-kit⁺ mast cells, act as immature progenitors in circulation, playing a critical role in liver fibrosis. Furthermore, c-kit is also a proto-oncogene. Notably, c-kit overexpression regulates gastrointestinal stromal tumors. Various studies have explored on c-kit and hepatocellular carcinoma, nevertheless, the intricate roles of c-kit in the liver are largely understudied. Herein, we extensively summarize previous studies geared toward providing hints for future clinical and basic research.

Immunohistochemical study of CD117 in various cutaneous melanocytic lesions

The aim of the present study was to carried out a comparative immunohistochemical evaluation of CD117 (c-Kit), a biomarker that evaluates both tumor progression and prognosis, in different melanocytic lesions, to emphasize the significance of this biomarker in malignant melanoma (MM). The study was performed on 55 cases, represented by a control group, which included 5 cases of simple nevi and 5 cases of dysplastic nevi, as well as a study group consisting of 35 cases of primary MM and 10 metastases (one intestinal, 3 cutaneous - one satellite and two distant as well as 6 in the lymph nodes). The study group included 15 cases of superficial spreading melanoma (SSM), 10 cases of nodular melanoma (NM), 3 lentigo maligna melanoma (LMM), 3 cases of acral lentiginous melanoma (ALM) and 4 cases of amelanotic MM. CD117 was found to be massively involved in the process of tumorigenesis of cutaneous malignancies, being immunohistochemically undetectable in benign neural lesions, but densely expressed in dysplastic lesions and in situ melanoma areas. In invasive cutaneous MMs, CD117 expression tended to decrease with neoplasia progression proceding into the tumorigenic, vertical growth phase, being lower in the profound dermal component of tumors and in nodular MMs. To eliminate the epidermal barriers and gain a proliferative advantage to allow the transition to the vertical growth phase, it seems that MM should lose expression of c-Kit. Cutaneous metastases were found to express CD117 at a level comparable to their primary tumors, suggesting that other mechanisms interfere directly with the metastatic process and not loss of c-Kit expression by itself. CD117 overexpression in cutaneous melanocytic lesions correlates significantly with increased immunostaining intensity, suggesting that the immunohistochemical evaluation of CD117 may be a good method for screening patients, who could benefit from personalized therapy with tyrosine kinase inhibitors.

Molecular Targets, Pathways, and Therapeutic Implications for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) represents one of the leading causes of cancer mortality worldwide. While significant advances have been made for the treatment of advanced hepatocellular carcinoma in the past few years, the prognosis remains poor and effective biomarkers to guide selection of therapies remain noticeably absent. However, several targeted therapies have been approved in the past few years that have improved the outlook for this disease. In this review, we will highlight the recent therapies approved for the treatment of advanced HCC and discuss promising therapeutic options, targets, and pathways for drug development and consideration for future clinical trials.

Recent Topics Concerning Combined Hepatocellular Cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma (CHC) is a relatively rare tumor with an incidence range of 1.0-4.7%. CHC is defined as a tumor containing unequivocal, intimately mixed components of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. The recent development of biochemical methodologies and cancer stem cell theory have paved the way for a clearer understanding of the histogenesis of CHC. The latest edited WHO classification published in 2010 adopted the concept of stem cell/hepatic progenitor cells in the pathological classification of CHC. Although this classification includes novel and unique concepts of histogenesis and facilitates the recognition of CHC, there are several problems with it in practice. To reduce confusion, an international group of hepatic pathologists, radiologists, surgeons, and clinicians formulated a nomenclature for CHC and issued a consensus article in 2018. In this review article, we discuss the problems with the latest WHO classification and introduce recent topics concerning CHC from pathologic and genetic points of view.

Overexpression of c-kit(CD117), relevant with microvessel density, is an independent survival prognostic factor for patients with HBV-related hepatocellular carcinoma

Background

To explore new biomarkers for indicating the recurrence and prognosis in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients after tumor resection, we investigated the expression and prognostic value of c-kit(CD117) in HBV-related HCC.

Materials and methods

Immunohistochemistry was used to estimate the expression of c-kit(CD117) and CD34 in the liver cancer tissues. The correlations between the expression of these biomarkers and the clinicopathologic characteristics were analyzed.

Results

The positive rate of c-kit(CD117) expression in 206 HCC cases was 48.1%, and c-kit expression was significantly related with CD34-positive microvessel density. CD34-microvessel density numbers were much higher in c-kit(+) HCC tissues than in c-kit(−) HCC tissues (44.13±17.01 vs 26.87±13.16, P=0.003). The expression of c-kit was significantly higher in patients with Edmondson grade III–IV (P<0.001) and TNM stage III (P<0.001). Moreover, Kaplan–Meier survival analysis showed that c-kit (P<0.001) expression was correlated with reduced disease-free survival (DFS). Multivariate analysis identified c-kit as an independent poor prognostic factor of DFS in HCC patients (P<0.001).

Conclusion

Increased c-kit expression could be considered as an independent unfavorable prognostic factor for predicting DFS in HBV-related HCC patients after surgery. These results could be used to identify patients at a higher risk of early tumor recurrence and poor prognosis.

Stemness-Related Markers in Cancer

Cancer stem cells (CSCs), with their self-renewal ability and multilineage differentiation potential, are a critical subpopulation of tumor cells that can drive tumor initiation, growth, and resistance to therapy. Like embryonic and adult stem cells, CSCs express markers that are not expressed in normal somatic cells and are thus thought to contribute towards a 'stemness' phenotype. This review summarizes the current knowledge of stemness-related markers in human cancers, with a particular focus on important transcription factors, protein surface markers and signaling pathways.

Hepatitis B virus PreS1 facilitates hepatocellular carcinoma development by promoting appearance and self-renewal of liver cancer stem cells

Hepatitis B virus (HBV) is a major etiologic agent of hepatocellular carcinoma (HCC). However, the molecular mechanism by which HBV infection contributes to HCC development is not fully understood. Here, we initially showed that HBV stimulates the production of cancer stem cells (CSCs)-related markers (CD133, CD117 and CD90) and CSCs-related genes (Klf4, Sox2, Nanog, c-Myc and Oct4) and facilitates the self-renewal of CSCs in human hepatoma cells. Cellular and clinical studies revealed that HBV facilitates hepatoma cell growth and migration, enhances white blood cell (WBC) production in the sera of patients, stimulates CD133 and CD117 expression in HCC tissues, and promotes the CSCs generation of human hepatoma cells and clinical cancer tissues. Detailed studies revealed that PreS1 protein of HBV is required for HBV-mediated CSCs generation. PreS1 activates CD133, CD117 and CD90 expression in normal hepatocyte derived cell line (L02) and human hepatoma cell line (HepG2 and Huh-7); facilitates L02 cells migration, growth and sphere formation; and finally enhances the abilities of L02 cells and HepG2 cells to induce tumorigeneses in nude mice. Thus, PreS1 acts as a new oncoprotein to play a key role in the appearance and self-renewal of CSCs during HCC development.

Evaluation of antiangiogenic efficacy in advanced hepatocellular carcinoma: Biomarkers and functional imaging

Many years after therapeutic wilderness, sorafenib finally showed a clinical benefit in patients with advanced hepatocellular carcinoma. After the primary general enthusiasm worldwide, some disappointments emerged particularly since no new treatment could exceed or at least match sorafenib in this setting. Without these new drugs, research focused on optimizing care of patients treated with sorafenib. One challenging research approach deals with identifying prognostic and predictive biomarkers of sorafenib in this population. The task still seems difficult; however appropriate investigations could resolve this dilemma, as observed for some malignancies where other drugs were used.

Keratin 19 protein expression is an independent predictor of survival in human hepatocellular carcinoma

AIM

We aimed to assess the clinicopathological relevance and prognostic significance of expression of the hepatic progenitor cell markers keratin 19 (K19), epithelial cell adhesion molecule (EpCAM) and CD117 (c-KIT) in a White series of hepatocellular carcinoma (HCC).

METHODS

We evaluated the immunohistochemical expression of K19, EpCAM and CD117 in 89 surgical specimens of HCC from Greek patients (mean age 66.7±11.3 years, male 75.2%) followed up for 39.6±25.3 months.

RESULTS

K19, EpCAM and CD117 expression was detected in tumour cells of 10.11, 15.38 and 3.7% HCCs, respectively. Female sex was correlated with EpCAM immunohistochemical expression (P=0.035), whereas no other significant relationship with clinicopathological parameters was observed. K19 positivity tended to be correlated with microvascular invasion (P=0.054). In univariate analysis, K19 positivity and microvascular invasion were found to be associated with decreased recurrence-free survival (P<0.001 and P=0.004, respectively) and overall survival (P=0.002 and P=0.029, respectively). EpCAM and CD117 positivity was not correlated with patient survival. In multivariate analysis, K19 positivity emerged as an independent predictor of recurrence-free survival (odds ratio=7.84, 95% confidence interval=2.658-22.912, P<0.001) and overall survival (odds ratio=3.845, 95% confidence interval=1.401-10.549, P=0.009).

CONCLUSION

Our study confirms the prognostic significance of K19 expression in Caucasian patients with HCCs, providing further evidence that it may be used to stratify HCC according to tumour aggressiveness.

Fullerol-fluorescein isothiocyanate-concanavalin agglutinin phosphorescent sensor for the detection of alpha-fetoprotein and forecast of human diseases

Based on the reaction of the active -OH group in fullerol (F) with the dissociated -COOH group in fluorescein isothiocyanate (FITC) to form an F-FITC and the enhanced effect of N, N-dimethylaniline (DMA) on phosphorescence signal of F-FITC, a new phosphorescent labeling reagent (DMA-F-FITC) was developed. What's more, a phosphorescent sensor for the determination of alpha-fetoprotein variant (AFP-V) has been designed via the coupling technique of the high sensitivity for affinity adsorption-solid substrate-room temperature phosphorimetry (AA-SS-RTP) with the strong specificity reaction between DMA-F-FITC-Con A and AFP-V. The DMA-F-FITC increased the number of luminescent molecules in the biological target which improved the sensitivity of phosphorescent sensor. The proposed sensor was responsive, simple, selective and sensitive, and it has been applied to the determination of trace AFP-V in human serum and the forecast of human diseases using phosphorescence emission wavelength of F or FITC, with the results agreed well with those obtained by enzyme-linked immunoassay (ELISA). Meanwhile, the mechanisms for the labeling reaction and the sensing detection of AFP-V were discussed.

Clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification

Combined hepatocellular-cholangiocarcinoma comprises <1% of all liver carcinomas. The histogenesis of combined hepatocellular-cholangiocarcinoma has remained unclear for many years. However, recent advances in hepatic progenitor cell (HPC) investigations have provided new insights. The concept that combined hepatocellular-cholangiocarcinoma originates from HPCs is adopted in the chapter "combined hepatocellular-cholangiocarcinoma" of the latest World Health Organization (WHO) classification. In this study, we conducted clinicopathologic analysis of combined hepatocellular-cholangiocarcinoma according to the latest WHO classification. Fifty-four cases were included in this study. Pathologic diagnosis was made according to the WHO classification. When a tumor contained plural histologic patterns, predominant histologic pattern (≥50%) was defined. Minor histologic patterns were also appended. Immunohistochemical staining with biliary markers (CK7, CK19, and EMA), hepatocyte paraffin (HepPar)-1, HPC markers (CD56, c-kit, CD133, and EpCAM), and vimentin was performed. Forty-five and 50 patients were analyzed for progression-free survival and overall survival, respectively. Ten, 1, 32, and 11 cases were diagnosed as: combined hepatocellular-cholangiocarcinoma, classical type; combined hepatocellular-cholangiocarcinoma, stem cell features, typical subtype; combined hepatocellular-cholangiocarcinoma, stem cell features, intermediate cell subtype; and combined hepatocellular-cholangiocarcinoma, stem cell features, cholangiolocellular type, respectively. Combined hepatocellular-cholangiocarcinomas usually have high expression of biliary markers. CD56, c-kit, and EpCAM were expressed to various degrees in all combined hepatocellular-cholangiocarcinomas apart from the hepatocellular carcinoma component of combined hepatocellular-cholangiocarcinoma, classical type. The expression of CD133 and vimentin was observed only in combined hepatocellular-cholangiocarcinoma, stem cell features of intermediate cell subtype and cholangiolocellular subtype. The expression of CD133, EpCAM, and vimentin was significantly high in combined hepatocellular-cholangiocarcinoma, subtypes with stem cell features, especially cholangiolocellular subtype. Minor histologic patterns were significantly frequent in combined hepatocellular-cholangiocarcinoma, subtypes with stem cell features, compared with combined hepatocellular-cholangiocarcinoma, classical type. There was no significant difference in clinical outcome between each subtype. Combined hepatocellular-cholangiocarcinoma has wide histologic diversity and shows immunophenotypic expression of not only biliary markers but also HPC markers to various degrees, suggesting that the histogenesis of combined hepatocellular-cholangiocarcinoma could be strongly associated with HPCs. Our results pathologically validate the latest WHO classification of combined hepatocellular-cholangiocarcinoma. However, the complex mixture of histologic subtypes has presented a challenge to the classification of combined hepatocellular-cholangiocarcinoma. Further study should be conducted using a large cohort to support this classification.

Human hepatocellular carcinomas with "Stemness"-related marker expression: keratin 19 expression and a poor prognosis

There is a recently proposed subtype of hepatocellular carcinoma (HCC) that is histologically similar to usual HCC, but characterized by the expression of "stemness"-related markers. A large-scale study on two different cohorts of HCCs was performed to investigate the clinicopathologic features and epithelial-mesenchymal transition (EMT)-related protein expression status of this subtype of HCCs. The expression status of stemness-related (e.g., keratin 19 [K19], cluster of differentiation [CD]133, epithelial cell adhesion molecule [EpCAM], and c-kit) and EMT-related markers (e.g., snail, S100A4, urokinase plasminogen activator receptor [uPAR], ezrin, vimentin, E-cadherin, and matrix metalloproteinase [MMP]2) were examined using tissue microarrays from cohort 1 HCCs (n = 137). K19 protein expression in cohort 2 HCCs (n = 237) was correlated with the clinicopathologic parameters and messenger RNA (mRNA) levels of K19, uPAR, VIL2, Snail, Slug, and Twist. K19, EpCAM, c-kit, and CD133 positivity were observed in 18.2%, 35.0%, 34.3%, and 24.8%, respectively. K19 was most frequently expressed in combination with at least one other stemness-related marker (92.0%). K19-positive HCCs demonstrated more frequent major vessel invasion and increased tumor size, compared to K19-negative HCCs (P < 0.05). K19 was most significantly associated with EMT-related protein expression (e.g., vimentin, S100A4, uPAR, and ezrin) (P < 0.05) and a poor prognosis (overall survival: P = 0.018; disease-free survival: P = 0.007) in cohort 1. In cohort 2, HCCs with high K19 mRNA levels demonstrated higher mRNA levels of Snail, uPAR, and MMP2 (P < 0.05). K19-positive HCCs demonstrated more frequent microvascular invasion, fibrous stroma, and less tumor-capsule formation, compared to K19-negative HCCs (P < 0.05). K19 expression was a significant independent predictive factor of poor disease-free survival (P = 0.032).

CONCLUSION

K19 was well correlated with clinicopathologic features of tumor aggressiveness, compared to other stemness-related proteins. K19-positive HCCs showed significantly increased EMT-related protein and mRNA expression, suggesting that they may acquire more invasive characteristics, compared to K19-negative HCCs through the up-regulation of EMT-associated genes.

The power and the promise of liver cancer stem cell markers

Recently, there has been growing support for the cancer stem cell (CSC) hypothesis, which states that primary tumors are initiated and maintained by a small subpopulation of cancer cells that possess "stem-like" characteristics. CSCs have been identified in many tumor types, including hepatocellular carcinoma (HCC). The dye, Hoechst 33342, has been used to enrich CSCs into a side population. Alternatively, liver CSCs (LCSCs) can be identified by several cell surface antigens, including CD133, CD90, CD44, EpCAM, and CD13. In this review, we summarized the recent evidence regarding LCSC markers and discussed the origin and function of these markers. LCSC markers are essential to identify and isolate these cells, to develop future therapies targeting CSCs, and to predict prognosis and efficacy of these therapies. However, definite LCSC markers are still controversial, because none of these markers is exclusively expressed by LCSCs in HCC. By combining several positive or negative markers, it may be possible to isolate and identify CSC fractions beyond the ability of each individual assay. By grouping LCSC markers according to their cellular origin, the properties of LCSC markers may be better studied and new markers may be found. Lastly, markers could be used to estimate the number of LCSCs and therefore predict outcomes. From our point of view, selecting HCC tissue samples from patients with different prognoses and detecting expression patterns of marker combinations may be a new method to identify new and unique markers.

Mechanism-related circulating proteins as biomarkers for clinical outcome in patients with unresectable hepatocellular carcinoma receiving sunitinib

Background

Several proteins that promote angiogenesis are overexpressed in hepatocellular carcinoma (HCC) and have been implicated in disease pathogenesis. Sunitinib has antiangiogenic activity and is an oral multitargeted inhibitor of vascular endothelial growth factor receptors (VEGFRs)-1, -2, and -3, platelet-derived growth factor receptors (PDGFRs)-α and -β, stem-cell factor receptor (KIT), and other tyrosine kinases. In a phase II study of sunitinib in advanced HCC, we evaluated the plasma pharmacodynamics of five proteins related to the mechanism of action of sunitinib and explored potential correlations with clinical outcome.

Methods

Patients with advanced HCC received a starting dose of sunitinib 50 mg/day administered orally for 4 weeks on treatment, followed by 2 weeks off treatment. Plasma samples from 37 patients were obtained at baseline and during treatment and were analyzed for vascular endothelial growth factor (VEGF)-A, VEGF-C, soluble VEGFR-2 (sVEGFR-2), soluble VEGFR-3 (sVEGFR-3), and soluble KIT (sKIT).

Results

At the end of the first sunitinib treatment cycle, plasma VEGF-A levels were significantly increased relative to baseline, while levels of plasma VEGF-C, sVEGFR-2, sVEGFR-3, and sKIT were significantly decreased. Changes from baseline in VEGF-A, sVEGFR-2, and sVEGFR-3, but not VEGF-C or sKIT, were partially or completely reversed during the first 2-week off-treatment period. High levels of VEGF-C at baseline were significantly associated with Response Evaluation Criteria in Solid Tumors (RECIST)-defined disease control, prolonged time to tumor progression (TTP), and prolonged overall survival (OS). Baseline VEGF-C levels were an independent predictor of TTP by multivariate analysis. Changes from baseline in VEGF-A and sKIT at cycle 1 day 14 or cycle 2 day 28, and change in VEGF-C at the end of the first off-treatment period, were significantly associated with both TTP and OS, while change in sVEGFR-2 at cycle 1 day 28 was an independent predictor of OS.

Conclusions

Baseline plasma VEGF-C levels predicted disease control (based on RECIST) and were positively associated with both TTP and OS in this exploratory analysis, suggesting that this VEGF family member may have utility in predicting clinical outcome in patients with HCC who receive sunitinib.

Trial registration

ClinicalTrials.gov: NCT00247676

Primary liver tumors: origin and target therapy

BACKGROUND

The liver is the largest gland and chief metabolic organ of the human body possessing a unique ability to regenerate. The general interest of primary liver tumors is noteworthy because of their increasing worldwide incidence and mortality. Recent studies have focused on the ancestors of mature hepatocytes, which are capable of proliferating, differentiating and self-renewing.

OBJECTIVE

To provide a brief and up-to-date review on the cellular origin of primary liver tumors and to examine the use of stem cells in potential future therapeutic attempts.

METHODS

A review of relevant literature.

RESULTS

It is clear that hepatic progenitor cells (HPCs) could be the basis of some hepatocellular carcinomas (HCC), cholangiocarcinomas (CHC), hepatocellular adenomas and hepatoblastomas. Cancer stem cell (CSC) theory emphasizes the role of hepatic stem cells in the development and progression of liver tumors.

CONCLUSION

The expression of HPCs markers may be used as new independent prognostic factors in HCC. Conventional treatments for HCC do not seem to be beneficial for the majority of patients and new therapeutic approaches such as gene therapy and targeted drug therapy are of great clinical interest.

c-kit (CD117) expression in human tumors and its prognostic value: an immunohistochemical analysis

c-kit functions as a tyrosine kinase receptor and represents a target for small molecule kinase inhibitors. The expression pattern for c-kit was studied in different human tumor types to their correlation with prognosis. Paraffin-embedded tumor tissues from 282 patients were analyzed immunohistochemically for c-kit expression. Survival and follow-up data were available from 192/282 (68%) patients. c-kit immunopositivity was found in 62/282 (22%) cases. c-kit expression was found in 14/83 (17%) colorectal cancers, in 13/62 (21%) breast cancers, in 7/20 sarcomas (35%), in 5/14 (36%) renal cell carcinomas, in 2/12 ovarian cancers (17%) and in 2/12 (17%) hepatocellular carcinomas. We found no significant correlation between c-kit expression and prognosis although a trend to a worse prognosis in patients with c-kit positive tumors could be observed. Expression of c-kit was found in tumor samples with varying intensities and infrequently.

Hepatic progenitor cells in liver cancers from Asian children

BACKGROUND/AIMS

Hepatoblastoma (HB) and hepatocellular carcinoma (HCC) are the two most common primary malignant liver tumours in children. Hepatic progenitor cells have been described and can be stained with K19, EpCAM and CD117. We investigated the morphology and staining patterns of primary liver tumours in Asian children.

METHODS

Four pathologists studied slides from 39 paediatric patients from Vietnam and Korea aged 8 months to 16 years. We performed immunohistochemical stains for K19, EpCAM and CD117, and polymerase chain reaction for tissue hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA.

RESULTS

There was agreement on the diagnosis of 24 cases of HCC and 10 cases of HB (one recurrent case). The diagnosis was split for six cases (HCC/HB). All 20 cases of HCC tested were HBV DNA+ and HCV RNA-. All nine cases of HB tested were HBV DNA-, while one was HCV RNA+. Of four HCC/HB cases tested, three were HBV DNA+ and all were HCV RNA-. By immunohistochemistry, 8/24 (33%) cases of HCC were K19+ and 18/24 (75%) were EpCAM+, 5/10 (50%) cases of HB were K19+ and 7/10 (70%) were EpCAM+ and 3/6 (50%) cases of HCC/HB were K19+ and 5/6 (83%) were EpCAM+. CD117 was negative in all 38 cases tested. Paediatric HCC has a morphology different from adult HCC, sometimes resembling HB, and a larger proportion of paediatric tumours have progenitor cell features.

CONCLUSIONS

HB and HCC in children may represent malignant transformation at an early stage in the cellular lineage and often arise from hepatic progenitor cells.

Expression of stem cell factor receptor c-kit in human nontumoral and tumoral hepatic cells

INTRODUCTION

The aim of this study was to examine and compare the stem cell factor receptor c-kit expression in hepatocellular carcinoma (HCC) with the corresponding peritumoral tissue. To confirm the immunohistochemical results in the investigated HCC tissues, HCC cell lines were analyzed for c-kit expression.

METHODS

Expression of c-kit (SCF receptor) has been evaluated in 72 HCC and in the corresponding surrounding nontumorous tissue. Additionally, immunohistochemical analysis reverse transcription-polymerase chain reaction was also used to examine the mRNA expression of c-kit protooncogene in tumor homogenates. Furthermore, three HCC cell lines (HUH-7, HepG2, and SK-Hep1) were used for gene-expression analysis of c-kit mRNA.

RESULTS

C-kit expression was detected immunohistochemically in 70% of HCC with different degrees of intensity. Moreover, c-kit expression could also be found in about 90% of the corresponding peritumoral noncirrhotic as well as in cirrhotic liver tissues. C-kit mRNA was detectable in 83% of HCC and in 75% of the corresponding peritumoral noncirrhotic as well as in 100% of corresponding peritumoral cirrhotic samples. In addition, two of the three HCC cell lines (HUH-7 and SK-Hep1) showed a well detectable PCR-product for c-kit.

CONCLUSION

Hepatocytes express the c-kit receptor at different grade of intensity under normal and altered pathological conditions. The presence of c-kit on HCC cell lines supports the assumption that SCF might play a role in the regulation of proliferative activity of tumorous and nontumorous hepatic cells.

Liver cancer stem cells: implications for a new therapeutic target

Hepatocellular carcinoma (HCC) is an aggressive tumour with a poor prognosis. Current therapeutic strategies against this disease target mostly rapidly growing differentiated tumour cells. However, the result is often dismal due to the chemoresistant nature of this tumour type. Recent research efforts on stem cells and cancer biology have shed light on new directions for the eradication of cancer stem cells (CSCs) in HCC. The liver is a distinctive organ with the ability of tissue renewal in response to injury. Based on the hypothesis that cancer development is derived from the hierarchy of the stem cell system, we will briefly discuss the origin of liver stem cells and its relation to HCC development. We will also summarize the current CSC markers in HCC and discuss their relevance to the treatment of this deadly disease.

PDGFRalpha: a new therapeutic target in the treatment of hepatocellular carcinoma?

BACKGROUND

Hepatocellular carcinoma (HCC) develops most often in a background of chronic inflammatory liver injury from viral infection or alcohol use. Most HCCs are diagnosed at a stage at which surgical resection is not feasible. Even in patients receiving surgery rates of recurrence and metastasis remain high. There are few effective HCC therapies and hence a need for novel, rational approaches to treatment. Platelet derived growth factor receptor-alpha (PDGFR-alpha) is involved in tumor angiogenesis and maintenance of the tumor microenvironment and has been implicated in development and metastasis of HCC.

OBJECTIVE

To examine PDGFR-alpha as a target for therapy of HCC and explore opportunities and strategies for PDGFR-alpha inhibition.

METHODS

A review of relevant literature.

RESULTS/CONCLUSIONS

Targeted inhibition of PDGFR-alpha is a rational strategy for prevention and therapy of HCC.

Efficacy, safety, and potential biomarkers of sunitinib monotherapy in advanced hepatocellular carcinoma: a phase II study

PURPOSE

To assess the safety and efficacy of sunitinib in patients with advanced hepatocellular carcinoma (HCC) and explore biomarkers for sunitinib response.

PATIENTS AND METHODS

We conducted a multidisciplinary phase II study of sunitinib, an antivascular endothelial growth factor receptor tyrosine kinase inhibitor, in advanced HCC. Patients received sunitinib 37.5 mg/d for 4 weeks followed by 2 weeks of rest per cycle. The primary end point was progression-free survival (PFS). We used functional magnetic resonance imaging to evaluate vascular changes in HCC after sunitinib treatment. Circulating molecular and cellular biomarkers were evaluated before and at six time points after sunitinib treatment.

RESULTS

Thirty-four patients were enrolled. The objective response rate was 2.9%, and 50% of patients had stable disease. Median PFS was 3.9 months (95% CI, 2.6 to 6.9 months), and overall survival was 9.8 months (95% CI, 7.4 months to not available). Grade 3 or 4 toxicities included leukopenia/neutropenia, thrombocytopenia, elevation of aminotransferases, and fatigue. Sunitinib rapidly decreased vessel leakiness, and this effect was more pronounced in patients with delayed progression. When evaluated early (at baseline and day 14) as well as over three cycles of treatment, higher levels of inflammatory molecules (eg, interleukin-6, stromal-derived factor 1alpha, soluble c-KIT) and circulating progenitor cells were associated with a poor outcome.

CONCLUSION

Sunitinib shows evidence of modest antitumor activity in advanced HCC with manageable adverse effects. Rapid changes in tumor vascular permeability and circulating inflammatory biomarkers are potential determinants of response and resistance to sunitinib in HCC. Our study suggests that control of inflammation might be critical for improving treatment outcome in advanced HCC.

Sorafenib and rapamycin induce growth suppression in mouse models of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common malignancy worldwide. Vascular endothelial growth factor, platelet derived growth factor and the Raf/mitogen-activated protein kinase/extracellular signal regulated kinase (Raf/MEK/ERK) signalling pathway regulates the growth, neovascularization, invasiveness and metastatic potential of HCC. In this study, we investigated the in vivo antitumour activity and mechanisms of action of sorafenib tosylate on four patient-derived HCC xenografts. Sorafenib dosed at 50 mg/kg and 100 mg/kg inhibited tumour growth by 85% and 96%, respectively. Sorafenib-induced growth suppression and apoptosis were associated with inhibition of angiogenesis, down-regulation of phospho-platelet-derived growth factor receptor beta Tyr1021, phospho-eIF4E Ser209, phospho-c-Raf Ser259, c-Raf, Mcl-1, Bcl-2, Bcl-x and positive cell cycle regulators, up-regulation of apoptosis signalling kinase-1, p27 and p21. Expression of IGF-1Rbeta and phosphorylation of c-Raf Ser338, MEK1/2 Ser217/221 and ERK1/2 Thr202/Tyr204 were increased by sorafenib treatment. Phosphorylation of mammalian target-of-rapamycin (mTOR) targets (p70S6K, S6R and 4EBP1) was reduced by sorafenib in sorafenib-sensitive lines but activated in sorafenib-less-sensitive 10-0505 xenograft. Sorafenib-induced phosphorylation of c-met, p70S6K and 4EBP1 was significantly reduced when 10-0505 cells were co-treated with anti-human anti-HGF antibody, suggesting that treatment with sorafenib leads to increased HGF secretion and activation of c-met and mTOR targets. Treatment of 10-0505 tumours with sorafenib plus rapamycin resulted in growth inhibition, inhibition of vascular endothelial growth factor receptor-2 phosphorylation, increased apoptosis and completely blocked sorafenib-induced phosphorylation of mTOR targets and cyclin B1 expression. These data also provide a strong rationale for clinical investigation of sorafenib in combination with mTOR inhibitors in patients with HCC.

Expression of c-kit protooncogen in hepatitis B virus-induced chronic hepatitis, cirrhosis and hepatocellular carcinoma: has it a diagnostic role?

AIM

There are more than 350 million people worldwide chronically infected with hepatitis B virus (HBV), who are at high risk for the development of hepatitis, cirrhosis and hepatocellular carcinoma (HCC). Because of the conflicting results about c-kit expression in HCC and the key role played by c-kit in gastrointestinal stromal tumours (GIST) and other solid tumours, the aim of this study was to determine c-kit expression in the course of hepatitis B infection.

MATERIALS AND METHODS

Paraffin-embedded tissues in Cukurova University Faculty of Medicine Department of Pathology between January 2002 and February 2006 were searched restrospectively to investigate this issue. We performed immunohistochemistry on biopsies of 125 patients with HBV infection, grouped as: mild, moderate and severe hepatitis, cirrhosis and HCC, 25 patients in each of them, using anti c-kit monoclonal antibody. The severity of parenchymal inflammation and of interface hepatitis was semiquantitatively graded on a haematoxylin and eosin stained paraffin sections. Additionally, 50 more HCC, formed on HBV basis, were studied to determine the prevalence of c-kit overexpression.

RESULTS

In cirrhotic liver, lower intensity of staining and rarely c-kit positivity were present. The greatest number of the c-kit positivity and higher intensity of staining was found in the livers of patients with severe hepatitis and HCC. In chronic hepatitis B infection, the staining intensity was parallel with the grade and stage of the disease. In the areas where fibrosis was seen, c-kit positivity was rare or absent. In the HCC specimens, c-kit positivity appeared both inside and around the cancerous nodes. C-kit expression was observed in 62 of 75 HCC tissue specimens (82%) (p < 0.001).

CONCLUSIONS

C-kit positivity was observed in the mitotic, proliferating and also dysplastic hepatic cells. These results suggest that c-kit expression may be used as an early diagnostic indicator for HBV induced HCC.

c-Kit expression in human normal and malignant stem cells prognostic and therapeutic implications

The human stem cell factor/c-Kit signaling pathway is pivotal for the survival of embryonic, foetal and adult stem cells and for their fundamental role in generating healthy functioning cell and tissue types during embryonic, foetal and adult life. Common biological features between human stem cells and cancer cells include (A) self-renewal, (B) extensive capacity of proliferation, (C) migration to and homing at distant sites and (D) resistance to toxic agents. Given these shared attributes, cancer was proposed to originate from transforming mutation(s) in normal stem cells that dysregulate their physiological programs. This theory has been recently supported by the findings that among all malignant cells within a particular tumour, only cell fraction expressing stem cell markers such as c-Kit named 'cancer stem cells' has the exclusive potential to generate tumour cell population. The involvement of c-Kit and its mutation in various haematological malignancies and solid tumours are reviewed. The impacts of dysregulated c-Kit as oncogenic tyrosine kinase on autocrine stimulation and resistance to chemotherapy of cancer stem cells are evaluated. The significance and efficacy of molecular therapeutic targeting of c-Kit signaling pathway in the management of patients with c-Kit-positive malignancies are appraised.

Determination of trace α-fetoprotein variant by affinity adsorption solid substrate-room temperature phosphorimetry and its application to the forecast of human diseases

In the presence of ion perturber LiAc, 4-generation polyamidoamine dendrimers (4G-D) could emit strong and stable room temperature phosphorescence (RTP) signal at lambda(max)(ex)/lambda(max)(em) = 511.8/675.3 nm on nitrocellulose membrane (NCM), and Triton X-100 could sharply enhance the RTP signal of 4G-D. Triton X-100-4G-D was used to label concanavalin agglutinin (Con A) to get the labeling product Triton X-100-4G-D-Con A. Quantitative specific affinity adsorption (AA) reaction between Triton X-100-4G-D-Con A and alpha-fetoprotein variant (AFP-V) could be carried out on the surface of NCM, whose product Triton X-100-4G-D-Con A-AFP-V could emit strong and stable RTP and its deltaI(p) was proportional to the content of AFP-V. According to the facts above, a new affinity adsorption solid substrate-room temperature phosphorimetry (AA-SS-RTP) for the determination of trace AFP-V by Con A labeled with Triton X-100-4G-D was established. Detection limits of this method were 0.23 fg spot(-1) (direct method, corresponding concentration: 5.8x10(-13) g mL(-1)) and 0.13 fg spot(-1) (sandwich method, corresponding concentration: 3.2x10(-13) g mL(-1)). It has been successfully applied to determine the content of AFP-V in human serum and forecast human diseases, for its high sensitivity, long RTP lifetime, good repeatability, high accuracy and little background perturbation with lambda(max)(em) at the long wavelength area. Meanwhile, the mechanism for the determination of trace AFP-V using AA-SS-RTP was also discussed.