Increased Expression of Circulating Cancer Stem Cell Markers During the Perioperative Period Predicts Early Recurrence After Curative Resection of Hepatocellular Carcinoma.

BACKGROUND: This study was designed to investigate the correlation between postoperative recurrence of hepatocellular carcinoma (HCC) and perioperative expression and dynamic changes in cancer stem cell (CSC) markers in tumors and peripheral blood. METHODS: In HCC patients who underwent curative resection (n = 64) or liver transplantation (LT) (n = 17), mRNA levels for K19, EpCAM, and CD44 in peripheral blood and HCC tissues before and after operation were examined using real-time RT-PCR. Postoperative recurrence was analyzed in patients who underwent resection. Study participants were divided into high and low ratio groups, according to the ratio of postoperative to preoperative mRNA levels for each marker. RESULTS: K19 and CD44 mRNA levels in HCC tissues were higher in patients with recurrence than those without recurrence (p < 0.05 for all). Preoperative peripheral levels of K19 and EpCAM mRNA were higher in LT patients than in resection patients, and they were also significantly higher in cirrhotic patients of Child-Pugh Class B or C than those of Child-Pugh Class A (p < 0.05 for all). A high ratio of K19 mRNA was associated with lower relapse-free rate. Additionally, a high ratio for both K19 and CD44 mRNA was an independent poor prognostic factor for relapse-free survival (hazard ratio = 3.382, p = 0.016). CONCLUSIONS: Preoperative peripheral levels of K19 and EpCAM mRNA were influenced by background liver status and HCC. Additionally, the ratio of postoperative to preoperative mRNA levels for CSC markers, especially K19 and CD44, was shown to be important to predict HCC recurrence.

A fibrous stromal component in hepatocellular carcinoma reveals a cholangiocarcinoma-like gene expression trait and epithelial-mesenchymal transition.

UNLABELLED: Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the major primary liver cancers in adults. The phenotypic overlap between HCC and CC has been shown to comprise a continuous liver cancer spectrum. As a proof of this concept, a recent study demonstrated a genomic subtype of HCC that expressed CC-like gene expression traits, such as CC-like HCC, which revealed the common genomic trait of stem-cell-like properties and aggressive clinical outcomes. Scirrhous HCC (S-HCC), a rare variant of HCC, is characterized by abundant fibrous stroma and has been known to express several liver stem/progenitor cell markers. This suggests that S-HCC may harbor common intermediate traits between HCC and CC, including stem-cell traits, which are similar to those of CC-like HCC. However, the molecular and pathological characteristics of S-HCC have not been fully evaluated. By performing gene-expression profiling and immunohistochemical evaluation, we compared the morphological and molecular features of S-HCC with those of CC and HCC. S-HCC expresses both CC-like and stem-cell-like genomic traits. In addition, we observed the expression of core epithelial-mesenchymal transition (EMT)-related genes, which may contribute to the aggressive behavior of S-HCC. Overexpression of transforming growth factor beta (TGF-ß) signaling was also found, implying its regulatory role in the pathobiology of S-HCC. CONCLUSION: We suggest that the fibrous stromal component in HCC may contribute to the acquisition of CC-like gene-expression traits in HCC. The expression of stem-cell-like traits and TGF-ß/EMT molecules may play a pivotal role in the aggressive phenotyping of S-HCC. (HEPATOLOGY 2012;55:1776-1786).

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

UNLABELLED: 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.

Invasion and EMT-associated genes are up-regulated in B viral hepatocellular carcinoma with high expression of CD133-human and cell culture study.

Hepatocellular carcinomas (HCCs) with expression of stem/progenitor cell markers including CD133 have been reported to have more aggressive biological behavior, and epithelial-mesenchymal transition (EMT), closely related invasion, has been suggested to generate cancer stem cells. To elucidate biological characteristics of HCCs expressing CD133, we evaluated migration assay and the mRNA expression levels of CD133, invasion-associated genes [urokinase plasminogen activator receptor (uPAR), villin 2 (VIL2), and MMP1 and MMP2], and EMT regulators (Snail, Slug, Twist, E-cadherin, and N-cadherin) by real-time PCR in HCC cell lines including HepG2, Hep3B, Huh7, PLC/RFP/6, SNU423, SNU449, and SNU475. Same genes and pathological features were also investigated in 49 samples of hepatitis B virus-related human HCCs. In all HCC cell lines studied, CD133-positive cells showed higher cell migration activity and up-regulated invasion- and EMT-associated genes with increased N-cadherin and decreased E-cadherin expressions compared to CD133-negative cells. The human HCCs were divided into the CD133-high group (top 40%) and the CD133-low group (bottom 40%) according to the level of CD133 mRNA. The CD133-high group showed relatively frequent vascular invasion and significantly higher expression of invasion-associated genes [uPAR (p=0.002), MMP1 (p=0.01), and MMP2 (p=0.003)] and EMT regulators [Snail (p=0.002) and Twist (p=0.0003)] compared to the CD133-low group. In conclusion, our results suggest that there is a subtype of HCC with high expression of CD133, which might have more invasive characteristics by up-regulation of invasion-associated genes and EMT-associated genes.

Expression of recombinant endochitinase from the Antarctic bacterium, Sanguibacter antarcticus KOPRI 21702 in Pichia pastoris by codon optimization.

An endochitinase was previously purified and the gene was cloned from the psychrophilic Antarctic bacterium, Sanguibacter antarcticus (KCTC 13143). In the present study, recombinant endochitinase, rChi21702, was expressed using a yeast expression system (Pichia pastoris) and codon optimization. The expressed rChi21702 was purified by Phenyl-Sepharose column chromatography. Optimal expression yielded 1-mg purified enzyme from 1-L bioreactor culture. When p-NP-(GlcNAc)(2) was used as a substrate, the specific activity of the enzyme was determined to be 20U/mg. In vitro assays and thin-layer chromatography demonstrated that the recombinant enzyme has endochitinase activity that produces diacetyl-chitobiose as a dominant end product when chitooligomers, colloidal chitin, and the chromogenic p-NP-(GlcNAc)(2) are used as substrates. Optimal activity for rChi21702 was observed at 37 degrees C and a pH of 7.6. Interestingly, rChi21702 exhibited 63% of optimal activity at 10 degrees C and 44% activity at 0 degrees C. Taken together, the results indicate that rChi21702 has psychrotolerant endochitinase activity even after recombinant expression in yeast cells.

A small molecule inhibitor of ATPase activity of HSP70 induces apoptosis and has antitumor activities.

The heat shock protein HSP70 plays antiapoptotic and oncogenic roles, and thus its inhibition has been recognized as a potential avenue for anticancer therapy. Here we describe the small molecule, apoptozole (Az), which inhibits the ATPase activity of HSP70 by binding to its ATPase domain and, as a result, induces an array of apoptotic phenotypes in cancer cells. Affinity chromatography provides evidence that Az binds HSP70 but not other types of heat shock proteins including HSP40, HSP60, and HSP90. We also demonstrate that Az induces cancer cell death via caspase-dependent apoptosis by disrupting the interaction of HSP70 with APAF-1. Animal studies indicate that Az treatment retards tumor growth in a xenograft mouse model without affecting mouse viability. These studies suggest that Az will aid the development of new cancer therapies and serve as a chemical probe to gain a better understanding of the diverse functions of HSP70.

A patient-derived xenograft mouse model generated from primary cultured cells recapitulates patient tumors phenotypically and genetically.

BACKGROUND: Preclinical trials of cancer therapeutics require both in vitro and in vivo evaluations. Recently, a patient-derived xenograft model in immunodeficient mice has been reported as a valuable in vivo evaluation system. In our current study, we aimed to establish a more efficient and accurate system for preclinical trials by generating primary cancer cells from patients and performing xenograft transfers of these cells into mice. METHODS: Human lung cancer specimens (n = 4) obtained from chemo-naive patients were cultured in bronchiolar epithelial basal medium supplemented with growth factors, followed by inoculation into non-obese diabetic/severe combined immunodeficient mice. The generated tumors in the mice were validated phenotypically and genetically using the original specimen and primary cancer cells. RESULTS: Immunohistochemical analysis of marker proteins, including cytokeratin 7, cytokeratin 20, epidermal growth factor receptor, thyroid transcription factor-1, CD56, chromogranin, and synaptophysin, demonstrated that the xenograft tumors were originated from the patient tumors. Moreover, mutation profiling using the OncoMap System, which analyzes mutations at 440 sites in 41 tumor-related genes, showed the same patterns in both the patient and xenograft tumors. CONCLUSIONS: These results indicate that our animal system is suitable for the amplification of patient tumors and will therefore be beneficial for both in vivo and in vitro assessments and preclinical trials of chemotherapeutics. This has the potential to provide a very effective tool for future personalized therapy and for conducting translational lung cancer research.

Colorectal cancers from distinct ancestral populations show variations in BRAF mutation frequency.

It has been demonstrated for some cancers that the frequency of somatic oncogenic mutations may vary in ancestral populations. To determine whether key driver alterations might occur at different frequencies in colorectal cancer, we applied a high-throughput genotyping platform (OncoMap) to query 385 mutations across 33 known cancer genes in colorectal cancer DNA from 83 Asian, 149 Black and 195 White patients. We found that Asian patients had fewer canonical oncogenic mutations in the genes tested (60% vs Black 79% (P = 0.011) and White 77% (P = 0.015)), and that BRAF mutations occurred at a higher frequency in White patients (17% vs Asian 4% (P = 0.004) and Black 7% (P = 0.014)). These results suggest that the use of genomic approaches to elucidate the different ancestral determinants harbored by patient populations may help to more precisely and effectively treat colorectal cancer.