Hung-Han Hsu

Stathmin overexpression cooperates with p53 mutation and osteopontin overexpression, and is associated with tumour progression, early recurrence, and poor prognosis in hepatocellular carcinoma.

Stathmin, a major microtubule‐depolymerizing protein, is involved in cell cycle progression and cell motility. This study aimed to elucidate its role in the progression, early tumour recurrence (ETR), and prognosis of hepatocellular carcinoma (HCC). Stathmin mRNA was overexpressed in 88/156 (56%) resected, unifocal, primary HCCs, while p53 mutation was present in 72 (46%) and osteopontin mRNA overexpression in 79 (51%). Stathmin mRNA expression exhibited high concordance (93%) with protein expression in 107 cases examined by immunohistochemistry. Stathmin overexpression correlated with high α‐fetoprotein (>200 ng/ml, p = 0.02), larger tumour size (>5 cm, p = 0.012), high tumour grade (p < 0.0002), high tumour stage (stage IIIA–IV) with vascular invasion and various degrees of intrahepatic metastasis (p < 1 × 10−8), ETR (p = 0.003), and lower 5‐year survival (p = 0.0007). Stathmin protein expression was often more intense in the peripheral regions of tumour trabeculae, tumour borders, and portal vein tumour thrombi. Stathmin overexpression correlated with p53 mutation (p = 0.017) and osteopontin overexpression (p = 1 × 10−8), both of which were associated with vascular invasion (both p < 0.0001) and poorer prognosis (p < 0.0004 and p = 0.0004, respectively). Regardless of the status of p53 mutation or osteopontin expression, stathmin overexpression was associated with higher vascular invasion (all p < 0.0001). Approximately 90% of HCCs harbouring stathmin overexpression with concomitant p53 mutation or osteopontin overexpression exhibited vascular invasion, and hence the lowest 5‐year survival, p = 0.00018 and p = 0.0009, respectively. However, we did not find that stathmin overexpression exerted prognostic impact independent of tumour stage. In conclusion, stathmin expression correlates with metastatic potential, is an important prognostic factor for HCC, and may serve as a useful marker to predict ETR. Copyright

Microvessel density, cyclo‐oxygenase 2 expression, K‐ras mutation and p53 overexpression in colonic cancer

Tumour angiogenesis, cyclo‐oxygenase (COX) 2 expression, K‐ras mutation and p53 overexpression are commonly involved in colorectal tumorigenesis, but their interrelationship and clinicopathological effects remain inconclusive.

Leiomyosarcoma With Alternative Lengthening of Telomeres Is Associated With Aggressive Histologic Features, Loss of ATRX Expression, and Poor Clinical Outcome

Leiomyosarcoma is an aggressive soft tissue sarcoma with poor patient survival. Recently, it was shown that 53% to 62% of leiomyosarcomas use the alternative lengthening of telomeres (ALT) as their telomere maintenance mechanism. The molecular basis of this mechanism has not been elucidated. Studies of pancreatic neuroendocrine tumor have suggested that the inactivation of either &agr;-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain–associated (DAXX) protein is associated with the ALT phenotype. In this study, we sought to determine the clinicopathologic features of leiomyosarcoma with the ALT phenotype and the possible relationship between this phenotype and ATRX/DAXX expression. Telomerase reverse transcriptase gene (TERT) promoter mutation analysis was also performed. Ninety-two leiomyosarcomas derived from the uterus, retroperitoneum/intra-abdomen, and various other sites were analyzed. Telomere-specific fluorescence in situ hybridization revealed that 59% (51/86) of leiomyosarcomas had the ALT phenotype. Loss of ATRX expression was observed in 33% of the tumors (30/92), and all but 2 ATRX-deficient tumors were ALT positive. Both the ALT phenotype and loss of ATRX expression were associated with epithelioid/pleomorphic cell morphology, tumor necrosis, and poor differentiation. None of the 92 cases lost DAXX expression. No TERT promoter mutation was detected (n=39). For survival analysis, poor differentiation, high FNCLCC grade, tumor size, and ALT phenotype were correlated with poor overall survival in univariate analysis. Tumor size and ALT phenotype remained independent prognostic factors in multivariate analysis. We concluded that the ALT phenotype in the leiomyosarcoma is associated with aggressive histologic features, loss of ATRX expression, and poor clinical outcome.

Prognostic significance of insulin-like growth factor II mRNA-binding protein 3 expression in gastric adenocarcinoma.

Insulin‐like growth factor II mRNA‐binding protein (IMP) 3 is expressed in embryonic tissues and multiple cancers. The aim was to establish the prognostic value of IMP‐3 expression in gastric adenocarcinoma.

Alternative lengthening of telomeres and loss of ATRX are frequent events in pleomorphic and dedifferentiated liposarcomas

Telomerase activation and alternative lengthening of telomeres are two major mechanisms of telomere length maintenance. Soft tissue sarcomas appear to use the alternative lengthening of telomeres more frequently. Loss of α-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain-associated protein 6 (DAXX) expression has been implicated in the pathogenesis of alternative telomere lengthening in pancreatic endocrine neoplasm and glioma. The mechanism leading to the alternative lengthening of telomeres in liposarcoma remains unknown. Whereas alternative telomere lengthening was determined to be an indicator of poor prognosis in liposarcomas as a whole, its prognostic power has not been verified in any subtype of liposarcoma. In this study, we characterized the status of alternative telomere lengthening and expression of ATRX and DAXX in 111 liposarcomas (28 well-differentiated, 52 dedifferentiated, 20 myxoid or round cell, and 11 pleomorphic liposarcomas) by telomere fluorescence in situ hybridization and immunohistochemistry, respectively. Alternative lengthening of telomere was observed in 0% (0/16) of well-differentiated, 30% (14/46) of dedifferentiated, 5% (1/19) of myxoid or round cell, and 80% (8/10) of pleomorphic liposarcomas. Eighteen (16%) and one (1%) tumors were negative for ATRX and DAXX immunostaining, respectively. Remarkably, all cases with loss of either ATRX or DAXX expression had alternative lengthening of telomeres, and 83% (19/23) of tumors that had alternative lengthening of telomeres showed loss of either protein. The correlation between loss of either ATRX or DAXX and alternative telomere lengthening was 100% in dedifferentiated liposarcoma. The presence of alternative telomere lengthening in dedifferentiated liposarcoma suggested poor overall survival (hazard ratio=1.954, P=0.077) and was the most significant indicator of short progression-free survival (hazard ratio=3.119, P=0.003). In conclusion, we found that ATRX loss was the most likely mechanism of alternative telomere lengthening in liposarcoma and alternative telomere lengthening was a prognostic factor of poor outcome in dedifferentiated liposarcoma.

Comprehensive screening of alternative lengthening of telomeres phenotype and loss of ATRX expression in sarcomas.

According to cytogenetic aberrations, sarcomas can be categorized as complex or simple karyotype tumors. Alternative lengthening of telomeres is a telomere-maintenance mechanism common in sarcomas. Recently, this mechanism was found to be associated with loss of either α-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain-associated (DAXX) protein. We previously reported that alternative lengthening of telomeres and loss of ATRX expression were common in leiomyosarcoma, angiosarcoma, pleomorphic liposarcoma, and dedifferentiated liposarcoma. In the present study, we screened an additional 245 sarcomas of other types to determine the prevalence of alternative lengthening of telomeres, loss of ATRX/DAXX expression, and their relationship. Undifferentiated pleomorphic sarcomas were frequently alternative lengthening of telomeres positive (65%) and loss of ATRX was seen in approximately half of the alternative lengthening of telomeres-positive tumors. Nineteen of 25 myxofibrosarcomas were alternative lengthening of telomeres-positive, but only one was ATRX deficient. Three of 15 radiation-associated sarcomas were alternative lengthening of telomeres positive, but none of them was ATRX deficient. Alternative lengthening of telomeres and/or loss of ATRX were uncommon in malignant peripheral nerve sheath tumors, gastrointestinal stromal tumors, and embryonal rhabdomyosarcomas. By contrast, none of the 71 gene fusion-associated sarcomas was ATRX deficient or alternative lengthening of telomeres positive. All tumors exhibited preserved DAXX expression. Combining our previous studies and this study, a total of 384 sarcomas with complex karyotypes were examined, 83 of which were ATRX deficient (22%). By telomere-specific fluorescence in situ hybridization, 45% (138/308) were alternative lengthening of telomeres positive, 55% (76/138) of which were ATRX deficient. Loss of ATRX was highly associated with alternative lengthening of telomeres (P<0.001). We conclude that alternative lengthening of telomeres is a frequent telomere-maintenance mechanism in cytogenetically complex sarcomas. Loss of ATRX is highly associated with this feature.

Alternative lengthening of telomeres phenotype in malignant vascular tumors is highly associated with loss of ATRX expression and is frequently observed in hepatic angiosarcomas

Alternative lengthening of telomeres (ALT) is a mechanism using homologous recombination to maintain telomere length and sustain limitless replicability of cancer cells. Recently, ALT has been found to be associated with inactivation of either α-thalassemia/mental retardation syndrome X-linked (ATRX) or death domain-associated (DAXX) protein. In this study, 119 tumors (88 angiosarcomas, 11 epithelioid hemangioendotheliomas, and 20 Kaposi sarcomas) were analyzed to determine the ALT status, its relationship to loss of ATRX/DAXX expression, and the clinicopathological features. In addition, the mutation status in the telomerase reverse transcriptase gene (TERT) promoter was also studied. Loss of ATRX expression was observed in 21% (16/77) of the primary angiosarcomas and 9% (1/11) of epithelioid hemangioendotheliomas. DAXX expression was intact in all but 2 ATRX-deficient angiosarcomas. Telomere-specific fluorescence in situ hybridization assay showed 28% (17/61) of the primary angiosarcomas were ALT positive. Remarkably, ALT was highly associated with loss of ATRX expression: all but 2 ALT-positive angiosarcomas were ATRX deficient. Notably, hepatic angiosarcomas were frequently ATRX deficient (8/13) and/or ALT positive (8/12). None of the secondary angiosarcomas were ATRX/DAXX deficient or ALT positive. The only ATRX-deficient epithelioid hemangioendothelioma was positive for ALT. Forty-seven angiosarcomas were tested for TERT promoter mutation. Despite the fact that angiosarcoma occurs most commonly in sun-damaged skin, mutation was detected in only 1 radiation-associated angiosarcoma (2%). We conclude that ALT is an important telomere maintenance mechanism in primary angiosarcomas. This feature is highly associated with loss of ATRX expression and is frequently observed in hepatic angiosarcomas.

Differential response to H. pylori eradication therapy of co-existing diffuse large B-cell lymphoma and MALT lymphoma of stomach—significance of tumour cell clonality and BCL10 expression†

We recently reported that low‐grade mucosa‐associated lymphoid tissue lymphoma (MALToma) and diffuse large B‐cell lymphoma (DLBCL) with MALToma (DLBCL[MALT]) of stomach are equally responsive to H. pylori eradication therapy (HPET) and that H. pylori‐independent status is closely associated with nuclear translocation of BCL10. However, co‐existing MALToma and DLBCL components of gastric DLBCL(MALT) may respond differentially to HPET and the underlying mechanism remains unclear. Tumour tissue samples from 18 patients with microdissectable co‐existing MALToma and DLBCL cells were studied. The clonality of lymphoma cells was examined by polymerase chain reaction‐based amplification of the CDR3 region of the IgH gene and confirmed by DNA sequence analysis. BCL10 expression was determined by immunohistochemistry. Differential response of co‐existing MALToma and DLBCL to HPET was defined as complete eradication of one component while the other component remained. Five (27.8%) of the 18 patients showed different IgH gene rearrangements in the two components and three (60%) of these five patients had differential response of MALToma and DLBCL to HPET. By contrast, 13 patients showed identical IgH gene rearrangements and only one (8%) of them had differential response of the two components to HPET (p = 0.044). Further, all four patients with differential response of MALToma and DLBCL to HPET showed nuclear expression of BCL10 in the H. pylori‐independent component and cytoplasmic expression of BCL10 in the H. pylori‐dependent component while the expression patterns of BCL10 were identical in both of these components in the 14 patients who had similar tumour response to HPET. We conclude that different clonality is a common reason for the differential response of co‐existing MALToma and DLBCL of gastric DLBCL(MALT) to HPET and that immunohistochemical examination of BCL10 expression may help to identify the co‐existence of these components. Copyright