Strong smooth muscle differentiation is dependent on myocardin gene amplification in most human retroperitoneal leiomyosarcomas.

Myocardin (MYOCD), a serum response factor (SRF) transcriptional cofactor, is essential for cardiac and smooth muscle development and differentiation. We show here by array-based comparative genomic hybridization, fluorescence in situ hybridization, and expression analysis approaches that MYOCD gene is highly amplified and overexpressed in human retroperitoneal leiomyosarcomas (LMS), a very aggressive well-differentiated tumor. MYOCD inactivation by shRNA in a human LMS cell line with MYOCD locus amplification leads to a dramatic decrease of smooth muscle differentiation and strongly reduces cell migration. Moreover, forced MYOCD expression in three undifferentiated sarcoma cell lines and in one liposarcoma cell line confers a strong smooth muscle differentiation phenotype and increased migration abilities. Collectively, these results show that human retroperitoneal LMS differentiation is dependent on MYOCD amplification/overexpression, suggesting that in these well-differentiated LMS, differentiation could be a consequence of an acquired genomic alteration. In this hypothesis, these tumors would not necessarily derive from cells initially committed to smooth muscle differentiation. These data also provide new insights on the cellular origin of these sarcomas and on the complex connections between oncogenesis and differentiation in mesenchymal tumors.

Telomerase activity and human telomerase reverse transcriptase mRNA expression in soft tissue tumors: correlation with grade, histology, and proliferative activity.

Telomerase activity (TA) is detected in most human cancers but, with few exceptions, not in normal somatic cells. Little is known about TA in soft tissue tumors. We have examined a series of benign and malignant soft tissue tumors for TA using the telomerase repeat amplification protocol assay. Analysis of the expression of the human telomerase reverse transcriptase was also carried out using RT-PCR. TA was undetectable in benign lesions (15 of 15) and low-grade sarcomas (6 of 6) and was detectable in 50% (19 of 38) of intermediate-/high-grade sarcomas. Although the presence of TA in soft tissue tumors is synonymous with malignancy, it is neither a reliable method in making the distinction between reactive/benign and malignant (especially low-grade) lesions nor a reliable marker of tumor aggressiveness. Leiomyosarcomas and storiform/pleomorphic malignant fibrous histiocytomas rarely showed TA, irrespective of their grade. A strong correlation between human telomerase reverse transcriptase mRNA expression and TA was observed, supporting the close relationship between both parameters. No significant relationship was observed between proliferative activity (as assessed by MIB-1 immunolabeling) and TA. We verified that the absence of telomerase expression was not due to the presence of telomerase inhibitors and therefore alternative mechanism(s) for cell immortalization, yet to be determined, seem to be involved in the development and/or maintenance of some soft tissue sarcomas.

Constant p53 pathway inactivation in a large series of soft tissue sarcomas with complex genetics.

Alterations of the p53 pathway are among the most frequent aberrations observed in human cancers. We have performed an exhaustive analysis of TP53, p14, p15, and p16 status in a large series of 143 soft tissue sarcomas, rare tumors accounting for around 1% of all adult cancers, with complex genetics. For this purpose, we performed genomic studies, combining sequencing, copy number assessment, and expression analyses. TP53 mutations and deletions are more frequent in leiomyosarcomas than in undifferentiated pleomorphic sarcomas. Moreover, 50% of leiomyosarcomas present TP53 biallelic inactivation, whereas most undifferentiated pleomorphic sarcomas retain one wild-type TP53 allele (87.2%). The spectrum of mutations between these two groups of sarcomas is different, particularly with a higher rate of complex mutations in undifferentiated pleomorphic sarcomas. Most tumors without TP53 alteration exhibit a deletion of p14 and/or lack of mRNA expression, suggesting that p14 loss could be an alternative genotype for direct TP53 inactivation. Nevertheless, the fact that even in tumors altered for TP53, we could not detect p14 protein suggests that other p14 functions, independent of p53, could be implicated in sarcoma oncogenesis. In addition, both p15 and p16 are frequently codeleted or transcriptionally co-inhibited with p14, essentially in tumors with two wild-type TP53 alleles. Conversely, in TP53-altered tumors, p15 and p16 are well expressed, a feature not incompatible with an oncogenic process.

Isolated cerebral metastasis of a triceps muscle leiomyosarcoma: A case report.

Abstract Leiomyosarcomas are rare malignant neoplasms. Intracranial metastases of this tumour are even less frequently observed and have mostly been described from uterine leiomyosarcomas. In this article, we describe the case of a single right frontal subcortical cerebral metastasis in a patient with a right triceps muscle leiomyosarcoma. A right-sided frontal craniotomy with macroscopically complete tumour removal was performed, followed by combined radio-chemotherapy. The patient died 10 months after the initial diagnosis of the intracranial metastasis due to systemic tumour progression, without any evidence of intracranial recurrence.

Prognostic factors in early-stage leiomyosarcoma of the uterus.

Uterine leiomyosarcomas (LMSs) are rare cancers representing less than 1% of all uterine malignancies. Clinical International Federation of Gynecology and Obstetrics (FIGO) stage is the most important prognostic factor. Other significant prognostic factors, especially for early stages, are difficult to establish because most of the published studies have included localized and extra-pelvian sarcomas. The aim of our study was to search for significant prognostic factors in clinical stage I and II uterine LMS. The pathologic features of 108 uterine LMS including 72 stage I and II lesions were reviewed using standardized criteria. The prognostic significance of different pathologic features was assessed. The median follow-up in the whole group was 64 months (range, 6-223 months). The 5-year overall survival (OS) and metastasis-free interval and local relapse-free interval rates in the whole group and early-stage group (FIGO stages I and II) were 40% and 57%, 42% and 50%, 56% and 62%, respectively. Clinical FIGO stage was the most important prognostic factor for OS in the whole group (P = 4 x 10). In the stage I and II group, macroscopic circumscription was the most significant factor predicting OS (P = 0.001). In the same group, mitotic score and vascular invasion were associated with metastasis-free interval (P = 0.03 and P = 0.04, respectively). Uterine LMSs diagnosed using standardized criteria have a poor prognosis, and clinical FIGO stage is an ominous prognostic factor. In early-stage LMS, pathologic features such as mitotic score, vascular invasion, and tumor circumscription significantly impact patient outcome.

Docetaxel and gemcitabine combination in 133 advanced soft-tissue sarcomas: a retrospective analysis.

Advanced soft-tissue sarcomas are usually resistant to cytotoxic agents such as doxorubicin and ifosfamide. Antitumor activity has been observed for gemcitabine and docetaxel combination. We conducted a retrospective study on 133 patients (58 males/75 females) with unresectable or metastatic soft-tissue sarcoma. The median age at diagnosis was 51.7 (18-82), with 76 patients with leiomoyosarcoma and 57 patients with other histological subtypes. The initial localizations were limb (44), uterine (32), retroperitoneal (23) and organs or bone (34). Patients received 900 mg/m2 of gemcitabine (days 1 and 8) over 90 min plus 100 mg/m2 of docetaxel (day 8), intravenously every 21 days. Gemcitabine/docetaxel combination was well tolerated with an overall response of 18.4% and with no clear statistical difference between leiomyosarcomas and other histological subtypes (24.2% versus 10.4% (p=0.06)). No difference was found between uterine soft-tissue sarcomas versus others. The median overall survival was 12.1 months (1-28). Better overall survival was correlated with leiomyosarcoma (p=0.01) and with the quality of the response, even for patients with stable disease (p<10(-4)). No statistical difference was found for the initial localization. Response to treatment and overall survival were better for patients in World Health Organization (WHO) performance status classification (PS) 0 at baseline versus patients in WHO PS-1, 2 or 3 (p=0.023 and p<10(-4), respectively). Gemcitabine/docetaxel combination was tolerable and demonstrated better response and survival for leiomyosarcoma, especially for patients in WHO PS-0 at baseline. For the other histological subtypes, the response was not encouraging, but the survival for patients in response or stable suggests further investigation.