F. Sartori

Inhibition of Connective Tissue Growth Factor (CTGF/CCN2) Expression Decreases the Survival and Myogenic Differentiation of Human Rhabdomyosarcoma Cells

Connective tissue growth factor (CTGF/CCN2), a cysteine-rich protein of the CCN (Cyr61, CTGF, Nov) family of genes, emerged from a microarray screen of genes expressed by human rhabdomyosarcoma cells. Rhabdomyosarcoma is a soft tissue sarcoma of childhood deriving from skeletal muscle cells. In this study, we investigated the role of CTGF in rhabdomyosarcoma. Human rhabdomyosarcoma cells of the embryonal (RD/12, RD/18, CCA) and the alveolar histotype (RMZ-RC2, SJ-RH4, SJ-RH30), rhabdomyosarcoma tumor specimens, and normal skeletal muscle cells expressed CTGF. To determine the function of CTGF, we treated rhabdomyosarcoma cells with a CTGF antisense oligonucleotide or with a CTGF small interfering RNA (siRNA). Both treatments inhibited rhabdomyosarcoma cell growth, suggesting the existence of a new autocrine loop based on CTGF. CTGF antisense oligonucleotide-mediated growth inhibition was specifically due to a significant increase in apoptosis, whereas cell proliferation was unchanged. CTGF antisense oligonucleotide induced a strong decrease in the level of myogenic differentiation of rhabdomyosarcoma cells, whereas the addition of recombinant CTGF significantly increased the proportion of myosin-positive cells. CTGF emerges as a survival and differentiation factor and could be a new therapeutic target in human rhabdomyosarcoma.

Gene expression profiling identifies potential relevant genes in alveolar rhabdomyosarcoma pathogenesis and discriminates PAX3-FKHR positive and negative tumors

We analyzed the expression signatures of 14 tumor biopsies from children affected by alveolar rhabdomyosarcoma (ARMS) to identify genes correlating to biological features of this tumor. Seven of these patients were positive for the PAX3‐FKHR fusion gene and 7 were negative. We used a cDNA platform containing a large majority of probes derived from muscle tissues. The comparison of transcription profiles of tumor samples with fetal skeletal muscle identified 171 differentially expressed genes common to all ARMS patients. The functional classification analysis of altered genes led to the identification of a group of transcripts (LGALS1, BIN1) that may be relevant for the tumorigenic processes. The muscle‐specific microarray platform was able to distinguish PAX3‐FKHR positive and negative ARMS through the expression pattern of a limited number of genes (RAC1, CFL1, CCND1, IGFBP2) that might be biologically relevant for the different clinical behavior and aggressiveness of the 2 ARMS subtypes. Expression levels for selected candidate genes were validated by quantitative real‐time reverse‐transcription PCR.

Defining the gene expression signature of rhabdomyosarcoma by meta-analysis

BackgroundRhabdomyosarcoma is a highly malignant soft tissue sarcoma in childhood and arises as a consequence of regulatory disruption of the growth and differentiation pathways of myogenic precursor cells. The pathogenic pathways involved in this tumor are mostly unknown and therefore a better characterization of RMS gene expression profile would represent a considerable advance. The availability of publicly available gene expression datasets have opened up new challenges especially for the integration of data generated by different research groups and different array platforms with the purpose of obtaining new insights on the biological process investigated.ResultsIn this work we performed a meta-analysis on four microarray and two SAGE datasets of gene expression data on RMS in order to evaluate the degree of agreement of the biological results obtained by these different studies and to identify common regulatory pathways that could be responsible of tumor growth. Regulatory pathways and biological processes significantly enriched has been investigated and a list of differentially meta-profiles have been identified as possible candidate of aggressiveness of RMS.ConclusionOur results point to a general down regulation of the energy production pathways, suggesting a hypoxic physiology for RMS cells. This result agrees with the high malignancy of RMS and with its resistance to most of the therapeutic treatments. In this context, different isoforms of the ANT gene have been consistently identified for the first time as differentially expressed in RMS. This gene is involved in anti-apoptotic processes when cells grow in low oxygen conditions. These new insights in the biological processes responsible of RMS growth and development demonstrate the effective advantage of the use of integrated analysis of gene expression studies.

Spindle cell tumor with EWS-WT1 transcript and a favorable clinical course: a variant of DSCT, a variant of leiomyosarcoma, or a new entity? Report of 2 pediatric cases.

We report 2 intra-abdominal tumors originally diagnosed as leiomyosarcomas, occurring in adolescents, one as a second malignancy after a Hodgkin lymphoma. Both tumors exhibited unusual morphologic features characterized by spindle cells arranged in sheets or in fascicles, devoid of the typical desmoplastic stroma. Cytokeratins and mesenchymal markers, including smooth muscle actin, desmin, and muscle specific actin, were coexpressed in the tumor cells, whereas EMA was negative. Reverse transcription-polymerase chain reaction analysis showed an EWS-WT1 fusion transcript. Both patients are alive and in complete remission at 3 and 13 years after diagnosis, respectively. These tumors raise a variety of diagnostic possibilities. They could represent intra-abdominal desmoplastic small round cell tumor, with histologic features of epithelioid leiomyosarcoma or an unusual subtype of leiomyosarcoma with an EWS-WT1 transcript. Alternatively, they could represent an unrecognized subgroup of tumors with spindle cell morphology, bearing the same translocation as desmoplastic small round cell tumor, but characterized by a more favorable clinical course.

Results of a prospective minimal disseminated disease study in human rhabdomyosarcoma using three different molecular markers

Rhabdomyosarcoma (RMS) has 2 major histologic subtypes: alveolar (ARMS) and embryonal (ERMS). ARMS is more aggressive and prone to distant tumor dissemination, whereas ERMS tends to expand and recur locally. Little information is available on bone marrow involvement by RMS.

Pre-operative chemoradiotherapy in non-small cell lung cancer stage III patients. Feasibility, toxicity and long-term results of a phase II study

The aim of this study was to evaluate the feasibility, the response rate and the effect on survival of full dose polychemotherapy delivered concurrently with bifractionated radiotherapy at a radical dose, in a subset of patients with marginally resectable or unresectable stage IIIA-B non-small cell lung cancer (NSCLC). Treatment consisted of two courses of cisplatin 100 mg/m2 for 1 day plus etoposide 120 mg/m2 for 3 days delivered from day 1 to day 22, plus radiotherapy delivered in two cycles of 2560 cGy each from day 3 to day 12 and from day 24 to 33 (total dose 5120 cGy in 31 days). The daily dose was 320 cGy in two equal fractions. After surgery, three additional courses of cisplatin plus etoposide were planned. From February 1988 to June 1991, 39 patients with stage III NSCLC (19 were judged as having marginally resectable, 20 as having unresectable disease) were entered into the study. Out of 39 patients (22 squamous cell carcinoma, 17 adeno/large cell carcinoma), 24 had stage IIIa (62%) and 15 stage IIIb (38%). Median PS was 80 (70-90). A total of 78 (74 evaluable) concurrent cycles of pre-operative chemoradiotherapy were delivered. The prominent side-effect was leucopenia: leucopenia > or = grade 3 at nadir occurred in 20 cycles (27%), thrombocytopenia > or = grade 3 at nadir in seven cycles (9%), 19 patients (54%) had a treatment delay of 1 week between the two cycles. Other important toxicities were sepsis in 5 patients (13%), oesophagitis > grade 2 in 9 patients (23%) and pneumonitis in 5 patients (13%). The response rate was 67% (6 CR (complete response), 16%; 19 PR (partial response), 51%). A resection was subsequently performed in 20 (51%) patients: 14 out of 19 marginally resectable (74%) and 6 out 20 initially unresectable (30%) patients. One other patient had an exploratory thoracotomy. Surgical specimens were tumour-free in 3 patients (14%); in 8 patients (38%) only microscopic tumour was found, and in 10 (48%) macroscopic residual tumour was found. Out of 23 patients attaining a CR, 5 relapsed locally and 11 only distantly. At present, with a follow-up ranging from 64 to 90 months, 34 patients have died, 1 is alive with recurrent disease and 4 (17%) are alive without evidence of disease. Median survival was 16 months, with 18% 3-year survivors and 13% 5-year survivors. Resected patients had a median survival of 21 months, versus 10 months for unresected patients (P = 0.01). No significant difference was evident between stage IIIa and stage IIIb patients.