London Lucien Ooi

Microvascular invasion is a better predictor of tumor recurrence and overall survival following surgical resection for hepatocellular carcinoma compared to the Milan criteria.

Objective:To compare microvascular invasion (McVI) with parameters defined by the Milan criteria in predicting tumor recurrence and overall survival (OS) in patients with surgical resection (SR) for hepatocellular carcinoma (HCC). Summary Background Data:Although the Milan criteria is discriminatory for selecting patients with good outcomes in liver transplantation and SR for HCC, it neither adequately predict tumor recurrence nor explain differences in survival for patients with good liver function. McVI is a strong indicator of intrahepatic metastasis in HCC, but its relative significance for predicting clinical outcomes compared to the Milan criteria is unclear. Methods:Patients undergoing SR with curative intent from January 2000 to March 2009 at the Singapore General Hospital were followed up for long-term outcomes till January 1, 2010. They were stratified first by the Milan criteria and then by the presence of McVI and compared relative to OS. Results:Altogether, 454 of the 515 patients received curative SR. There were stratified into 4 groups (Milan+, McVI−), (Milan+, McVI+), (Milan−, McVI−), and (Milan−, McVI+). All pair-wise comparisons between groups relative to OS were significant except (Milan+, McVI−) (OS, 90%, 73%, and 60% at 1, 3, and 5 years) with (Milan−, McVI−) (OS, 86%, 71%, and 61% at 1, 3, 5 years) and (Milan+, McVI+) with (Milan−, McVI+). Multivariate Cox regression analysis showed that McVI was predictive of OS, after which Milan status did not add additional discriminative information. Conclusions:McVI is a better predictor of tumor recurrence and OS than the Milan criteria after SR for HCC. Assessment of McVI should aid in patient selection for adjuvant treatments to improve outcomes after SR.

An Appraisal of Surgical and Percutaneous Drainage for Pyogenic Liver Abscesses Larger Than 5 cm

Objective:To determine whether first-line treatment with percutaneous or surgical drainage of liver abscesses larger than 5 cm results in better clinical outcome. Summary Background Data:Pyogenic liver abscesses larger than 5 cm are currently treated by intravenous antibiotics and either percutaneous (PD) or surgical drainage (SD). Percutaneous techniques have been increasingly performed in place of open drainage as first-line treatment. This paradigm shift has been fueled by the drive for low-risk and less-invasive procedures and the surgical option being reserved for percutaneous failures. Yet there is a lack of data to support percutaneous drainage over open surgical drainage as first-line treatment. Methods:Over a 3-year period, 80 patients with liver abscesses larger than 5 cm amenable to PD and SD were included in the study. This situation was possible as 1 team of surgeons favored the use of PD and 1 team favored the use of SD as first-line treatment. The treatment outcomes in both groups were compared, and clinical end-points included time to defervescence of fever, failure of treatment, secondary procedures, hospital stay, morbidity, and mortality. Results:PD was performed in 36 patients and SD in 44 patients as first-line treatment. Clinical, laboratory, and abscess parameters were comparable in both groups. Sixty-four of 80 patients (80%) had multiloculated abscess. The time to defervescence of fever was not statistically significant (PD versus SD, 4.85 versus 4.38 days; P = 0.09). However, SD had less treatment failures (3 versus 10, P = 0.013), less requirement for secondary procedures (5 versus 13, P = 0.01), and shorter length of hospital stay (8 versus 11 days, P = 0.03). There was no difference in morbidity or mortality rates. Conclusions:The results of our study show that for large liver abscesses more than 5 cm, SD provides better clinical outcomes than PD in terms of treatment success, number of secondary procedures, and hospital stay with comparable morbidity and mortality rates. SD should be considered as first-line treatment of large liver abscesses.

Targeted inhibition of tumor-specific glutaminase diminishes cell-autonomous tumorigenesis

Glutaminase (GLS), which converts glutamine to glutamate, plays a key role in cancer cell metabolism, growth, and proliferation. GLS is being explored as a cancer therapeutic target, but whether GLS inhibitors affect cancer cell-autonomous growth or the host microenvironment or have off-target effects is unknown. Here, we report that loss of one copy of Gls blunted tumor progression in an immune-competent MYC-mediated mouse model of hepatocellular carcinoma. Compared with results in untreated animals with MYC-induced hepatocellular carcinoma, administration of the GLS-specific inhibitor bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES) prolonged survival without any apparent toxicities. BPTES also inhibited growth of a MYC-dependent human B cell lymphoma cell line (P493) by blocking DNA replication, leading to cell death and fragmentation. In mice harboring P493 tumor xenografts, BPTES treatment inhibited tumor cell growth; however, P493 xenografts expressing a BPTES-resistant GLS mutant (GLS-K325A) or overexpressing GLS were not affected by BPTES treatment. Moreover, a customized Vivo-Morpholino that targets human GLS mRNA markedly inhibited P493 xenograft growth without affecting mouse Gls expression. Conversely, a Vivo-Morpholino directed at mouse Gls had no antitumor activity in vivo. Collectively, our studies demonstrate that GLS is required for tumorigenesis and support small molecule and genetic inhibition of GLS as potential approaches for targeting the tumor cell-autonomous dependence on GLS for cancer therapy.

PXR Pharmacogenetics: Association of Haplotypes with Hepatic CYP3A4 and ABCB1 Messenger RNA Expression and Doxorubicin Clearance in Asian Breast Cancer Patients

Purpose: To characterize pregnane X receptor (PXR) polymorphic variants in healthy Asian populations [Chinese, Malay and Indian (n = 100 each)], and to investigate the association between PXR haplotypes and hepatic mRNA expression of PXR and its downstream target genes, CYP3A4 and ABCB1, as well as their influence on the clearance of doxorubicin in Asian breast cancer patients. Experimental Design:PXR genotyping was done by direct DNA sequencing, and PXR haplotypes and haplotype clusters were derived by expectation-maximization algorithm. Genotype-phenotype correlations were done using Mann-Whitney U test and Kruskal-Wallis test. Results: Significant interethnic variations were observed in PXR pharmacogenetics among the three Asian ethnic groups. The expression of PXR mRNA in liver tissues harboring the PXR*1B haplotype clusters was 4-fold lower compared with the non-PXR*1B (*1A + *1C) haplotype clusters [PXR*1B versus PXR*1A; P = 0.015; PXR*1B versus PXR*1C; P = 0.023]. PXR*1B-bearing liver tissues were associated with significantly lower expression of CYP3A4 (PXR*1B versus non-PXR*1B, P = 0.030) and ABCB1 (PXR*1B versus non-PXR*1B, P = 0.060) compared with non–PXR*1B-bearing liver tissues. Doxorubicin clearance in breast cancer patients harboring the PXR*1B haplotypes was significantly lower compared with patients carrying the non-PXR*1B haplotypes [PXR*1B versus non-PXR*1B, CL/BSA (L h−1 m−2): 20.84 (range, 8.68-29.24) versus 24.85 (range, 13.80-55.66), P = 0.022]. Conclusions: This study showed that PXR*1B was associated with reduced hepatic mRNA expression of PXR and its downstream targets, CYP3A4 and ABCB1. Genotype-phenotype correlates in breast cancer patients showed PXR*1B to be significantly associated with lower doxorubicin clearance, suggesting that PXR haplotype constitution could be important in influencing interindividual and interethnic variations in disposition of its putative drug substrates.

Solid pseudopapillary tumour of the pancreas

Background:u2003 Solid pseudopapillary tumour of the pancreas is a rare pancreatic tumour that occurs predominantly in women, with very few cases reported in men. This is a tumour with low malignancy potential and surgical resection usually results in cure.

Pharmacogenetics of SLCO1B1: haplotypes, htSNPs and hepatic expression in three distinct Asian populations

ObjectiveThe aim of this study was to characterize the population frequency of SLCO1B1 polymorphic variants in three distinct healthy Asian populations, namely Chinese (nu2009=u2009100), Malay (nu2009=u2009100) and Indian (nu2009=u2009100), and to explore the association between haplotype-tagged single nucleotide polymorphisms (htSNPs) on hepatic SLCO1B1 mRNA expression.MethodsThe distribution of polymorphic variants in the SLCO1B1 gene at eight loci that spanned approximately 48xa0kb was investigated in the three different Asian ethnic groups and in 32 non-cancerous liver tissues from Chinese patients.ResultsOf the 26 polymorphisms screened, we found eight polymorphic variants that differed in genotypic and allelic frequencies between the Chinese, Malay and Indian populations. Significant interethnic differences were observed in the genotype frequency distributions across the promoter SNP [g.-11187G>A (Pu2009=u20090.030)] as well as three coding region SNPs [c.388G>A (Pu2009<u20090.001); c.571T>C (Pu2009<u20090.001); c.597C>T (Pu2009<u20090.001)] in the healthy subjects. Haplotype analysis revealed 12 different haplotypes in both the Chinese and Malay populations and 18 haplotypes in the Indian population. In both the Malay and Indian populations, the htSNPs were c.388A>G, c.571T>C and c.597C>T, whereas in the Chinese population they were g.-11187G>A, c.388A>G and c.597C>T. The c.388A>G and c.597C>T htSNPs accounted for more than 70% of the variations between the three major haplotypes in each Asian ethnic group. In terms of the c.388A>G htSNPs, genotypic-phenotypic association analyses revealed that there was no effect on SLCO1B1 expression in hepatic tissues; in addition, no genotypic-phenotypic associations were evident with regards to the c.597C>T htSNP.ConclusionFuture studies should investigate the phenotypic effects of the c.388A>G htSNP on the disposition of OATP1B1 substrates in Asian populations.

FACTORS AFFECTING EARLY MORTALITY IN SPONTANEOUS RUPTURE OF HEPATOCELLULAR CARCINOMA

Background:u2003 Spontaneous rupture of hepatocellular carcinoma (HCC) is a catastrophic surgical emergency with high mortality rates. The aim of this study is to determine the factors associated with the prognosis and to assess the outcome of different management strategies.

Selective Tyrosine Hyperphosphorylation of Cytoskeletal and Stress Proteins in Primary Human Breast Cancers: Implications for Adjuvant Use of Kinase-Inhibitory Drugs

Purpose: Small-molecule growth factor receptor inhibitors block cell growth in vitro and downstream signaling in vivo, but controlled trials in patients with advanced solid tumors have yielded disappointing response rates. To clarify this discrepancy, we compared the patterns of tyrosine phosphoprotein expression in human cancer cells and primary tumors. Experimental Design: Immunoaffinity chromatography, two-dimensional electrophoresis, and antiphosphotyrosine immunoblotting were combined with mass spectrometry to determine the phosphoproteomic signatures of 40 matched normal and malignant tissues from patients with breast or liver cancer. The identities and abundance of the detected tyrosine phosphoproteins were compared with those of ligand-responsive A431 cells. Results: Patterns of tyrosine-phosphorylated proteins are similar among normal tissues of the same origin but vary markedly between different tissues. Primary breast tumors exhibit a strikingly homogeneous tyrosine phosphorylation profile, whereas liver cancers display greater phosphoproteomic diversity. The main breast-tumor-specific tyrosine phosphoproteins are cytoskeletal molecules (actin, tubulin, and vimentin) and molecular chaperones (Hsp70, Hsc71, and Grp75). In contrast, control studies in ligand-stimulated A431 human cancer cells revealed an additional phosphorylated subset of promitogenic phosphoproteins (Grb2, Shc, Jnk2, phospholipase C-γ, and phosphatidylinositol 3′-kinase). Conclusions: Identification of cytoskeletal and stress proteins as the most abundant tyrosine phosphoproteins in breast tumors implicates these molecules, rather than promitogenic effectors, as the prime stoichiometric substrates for kinase-inhibitory anticancer drugs in vivo. Because phosphorylated cytoskeletal proteins and chaperones mediate cell motility and apoptotic resistance, respectively, these data raise the intriguing possibility that small-molecule tyrosine kinase inhibitors may be of greatest value either as adjuvant antimetastatic/-invasive drugs or as chemo-/radiosensitizers.

The microtubule-associated protein PRC1 promotes early recurrence of hepatocellular carcinoma in association with the Wnt/β-catenin signalling pathway

Objectives Hepatocellular carcinoma (HCC) is the second leading cause of cancer mortality worldwide. Alterations in microtubule-associated proteins (MAPs) have been observed in HCC. However, the mechanisms underlying these alterations remain poorly understood. Our aim was to study the roles of the MAP protein regulator of cytokinesis 1 (PRC1) in hepatocarcinogenesis and early HCC recurrence. Design PRC1 expression in HCC samples was evaluated by microarray, immunoblotting and immunohistochemistry analysis. Molecular and cellular techniques including siRNA-mediated and lentiviral vector-mediated knockdown were used to elucidate the functions and mechanisms of PRC1. Results PRC1 expression was associated with early HCC recurrence and poor patient outcome. In HCC, PRC1 exerted an oncogenic effect by promoting cancer proliferation, stemness, metastasis and tumourigenesis. We further demonstrated that the expression and distribution of PRC1 is dynamically regulated by Wnt3a signalling. PRC1 knockdown impaired transcription factor (TCF) transcriptional activity, decreased Wnt target expression and reduced nuclear β-catenin levels. Mechanistically, PRC1 interacts with the β-catenin destruction complex, regulates Wnt3a-induced membrane sequestration of this destruction complex, inhibits adenomatous polyposis coli (APC) stability and promotes β-catenin release from the APC complex. In vivo, high PRC1 expression correlated with nuclear β-catenin and Wnt target expression. PRC1 acted as a master regulator of a set of 48 previously identified Wnt-regulated recurrence-associated genes (WRRAGs) in HCC. Thus, PRC1 controlled the expression and function of WRRAGs such as FANCI, SPC25, KIF11 and KIF23 via Wnt signalling. Conclusions We identified PRC1 as a novel Wnt target that functions in a positive feedback loop that reinforces Wnt signalling to promote early HCC recurrence.

Systemically delivered measles virus-infected mesenchymal stem cells can evade host immunity to inhibit liver cancer growth

BACKGROUND & AIMSnAlthough attenuated measles virus (MV) has demonstrated potent oncolytic activities towards human cancers, it has not yet been widely adopted into clinical practice. One of the major hurdles is the presence of pre-existing anti-MV immunity in the recipients. In this study, we have evaluated the combination of the potent oncolytic activity of the attenuated MV with the unique immunoprivileged and tumor-tropic biological properties of human bone marrow-derived mesenchymal stem cells (BM-hMSCs) to combat human hepatocellular carcinoma (HCC), orthotopically implanted in SCID mice, passively immunized with human neutralizing antibodies against MV as a preclinical model.nnnMETHODSnSCID mice were orthotopically implanted with patient-derived HCC tissues and established HCC cell lines. SCID mice were passively immunized with human neutralizing anti-measles antibodies. Bioluminescence and fluorescence imaging were employed to monitor the ability of systemically delivered MV-infected BM-hMSCs to infiltrate the implanted tumors and their effects on tumor growth.nnnRESULTSnSystemically delivered MV-infected BM-hMSCs homed to the HCC tumors implanted orthotopically in the liver and it was evidenced that BM-hMSCs could transfer MV infectivity to HCC via heterofusion. Furthermore, therapy with MV-infected BM-hMSCs resulted in significant inhibition of tumor growth in both measles antibody-naïve and passively-immunized SCID mice. By contrast, when cell-free MV viruses were delivered systemically, antitumor activity was evident only in measles antibody-naïve SCID mice.nnnCONCLUSIONSnMV-infected BM-hMSCs cell delivery system provides a feasible strategy to elude the presence of immunity against MV in most of the potential cancer patients to be treated with the oncolytic MV viruses.