Carlos Barranco

Versican Is Differentially Expressed in Human Melanoma and May Play a Role in Tumor Development

Undifferentiated human melanoma cell lines produce a large chondroitin sulfate proteoglycan, different from the well-known melanoma-specific proteoglycan mel-PG (Heredia and colleagues, Arch Biochem Biophys, 333: 198-206, 1996). We have identified this proteoglycan as versican and analyzed the expression of versican in several human melanoma cell lines. Versican isoforms are expressed in undifferentiated cell lines but not in differentiated cells, and the isoform expression pattern depends on the degree of cell differentiation. The V0 and V1 isoforms are found on cells with an early degree of differentiation, whereas the V1 isoform is present in cells with an intermediate degree of differentiation. We have also characterized some functional properties of versican on human melanoma cells: the purified proteoglycan stimulates cell growth and inhibits cell adhesion when cells are grown on fibronectin or collagen type I as substrates, and thus may facilitate tumor cell detachment and proliferation. Furthermore, we have analyzed the expression of versican in human melanocytic nevi and melanoma: 10 benign melanocytic nevi, 10 dysplastic nevi, 11 primary malignant melanomas, and 8 metastatic melanomas were tested. Immunoreactivity for versican was negative in benign melanocytic nevi, weakly to strongly positive in dysplastic nevi, and intensely positive in primary malignant melanomas and metastatic melanomas. Our results indicate that versican is involved in the progression of melanomas and may be a reliable marker for clinical diagnosis.

Role of fucosyltransferases in the association between apomucin and Lewis antigen expression in normal and malignant gastric epithelium

BACKGROUND In normal gastric epithelium, MUC5AC is detected in superficial epithelium associated with Lewis type 1 antigens and MUC6 is detected in antral glands with Lewis type 2. Therefore, the stomach constitutes an excellent model to examine the role of glycosyltransferases in determining the specificity of apomucin glycosylation. AIMS To determine the molecular basis of this association and to examine changes in expression of gastric and intestinal apomucins and their association with Lewis antigens during the gastric carcinogenesis process. METHODS Fucosyltransferase (FUT1, FUT2, FUT3) and mucin (MUC5AC, MUC6) transcripts were detected using reverse transcription-polymerase chain reaction. Apomucin (MUC2, MUC4, MUC5AC, MUC6) and Lewis antigen (types 1 and 2) expression were analysed using single and double immunohistochemistry and in situ hybridisation. RESULTS In the normal stomach, FUT1 is exclusively detected associated with MUC6; FUT2 is only detected when MUC5AC is present. This co-regulation is lost in gastric tumours, as is differential expression of MUC5AC and MUC6 in normal gastric epithelial cells. In gastric tumours, especially those with the intestinal phenotype, MUC2 and MUC4 genes are upregulated, and gastric-type and intestinal-type mucins are coexpressed. These changes are early events in the gastric carcinogenesis process, as they are detected in intestinal metaplasia. CONCLUSIONS The glycosylation pattern found in normal gastric epithelium is dictated by the specific set of fucosyltranferases expressed by the cells rather than by the apomucin sequence. The development of intestinal metaplasia and gastric cancer is associated with the appearance of cellular phenotypes that are absent from normal epithelium.

Oligonucleotide Array-CGH Identifies Genomic Subgroups and Prognostic Markers for Tumor Stage Mycosis Fungoides

Mycosis fungoide (MF) patients who develop tumors or extracutaneous involvement usually have a poor prognosis with no curative therapy available so far. In the present European Organization for Research and Treatment of Cancer (EORTC) multicenter study, the genomic profile of 41 skin biopsies from tumor stage MF (MFt) was analyzed using a high-resolution oligo-array comparative genomic hybridization platform. Seventy-six percent of cases showed genomic aberrations. The most common imbalances were gains of 7q33.3q35 followed by 17q21.1, 8q24.21, 9q34qter, and 10p14 and losses of 9p21.3 followed by 9q31.2, 17p13.1, 13q14.11, 6q21.3, 10p11.22, 16q23.2, and 16q24.3. Three specific chromosomal regions, 9p21.3, 8q24.21, and 10q26qter, were defined as prognostic markers showing a significant correlation with overall survival (OS) (P=0.042, 0.017, and 0.022, respectively). Moreover, we have established two MFt genomic subgroups distinguishing a stable group (0-5 DNA aberrations) and an unstable group (>5 DNA aberrations), showing that the genomic unstable group had a shorter OS (P=0.05). We therefore conclude that specific chromosomal abnormalities, such as gains of 8q24.21 (MYC) and losses of 9p21.3 (CDKN2A, CDKN2B, and MTAP) and 10q26qter (MGMT and EBF3) may have an important role in prognosis. In addition, we describe the MFt genomic instability profile, which, to our knowledge, has not been reported earlier.

Molecular diagnosis of dermatofibrosarcoma protuberans: a comparison between reverse transcriptase-polymerase chain reaction and fluorescence in situ hybridization methodologies.

Dermatofibrosarcoma protuberans (DFSP) is characterized by the presence of the t(17;22)(q22;q13) that leads to the fusion of the COL1A1 and PDGFB genes. This translocation can be detected by multiplex reverse transcriptase‐polymerase chain reaction (RT‐PCR) or fluorescence in situ hybridization (FISH) techniques. We have evaluated the usefulness of a dual color dual fusion FISH probe strategy for COL1A1/PDGFB detection in a series of 103 archival DFSPs and compared the obtained results with RT‐PCR analyses. FISH and RT‐PCR were carried out on paraffin embedded tissue samples. Regarding the RT‐PCR approach, all COL1A1 exons and exon 2 of PDGFB were evaluated. Sensitivity, specificity, positive and negative predictive values were assessed considering the histological diagnosis as the gold standard. We also analyzed the relationship between the genetic findings and the clinicopathological variables of the tumors. The COL1A1/PDGFB translocation was detected in 93% of DFSP. Both techniques showed a similar specificity (100%), but FISH was more sensitive than RT‐PCR (90% vs. 72%). Regarding, clinicopathological features, a higher percentage of positive cells detected by FISH was significantly associated with the fibrosarcomatous DFSP variant (P < 0.001). Interestingly, all CD34 negative DFSP (n = 5) were positive for COL1A1/PDGFB translocation by both techniques. In conclusion, the majority of DFSP harbor the COL1A1/PDGFB translocation and FISH technique should be recommended as a routine diagnostic tool, especially in cases showing unusual histopathological subtypes and/or immunohistochemical features.

MUC6 expression in breast tissues and cultured cells: Abnormal expression in tumors and regulation by steroid hormones

Neoplastic transformation of epithelial cells is commonly associated with alterations in the expression of mucin genes. The mechanisms involved in this process are largely unknown. MUC6, isolated from a stomach cDNA library, is mainly expressed in stomach antral glands, as detected by using in situ hybridization and immunohistochemistry. We examined MUC6 expression in normal and pathological breast tissues using immunohistochemistry with MUC6‐specific antibodies and in cultured breast cancer cells using immunocytochemistry and Northern blotting. MUC6 was generally not detected in normal breast (1/11) but was detected in fibrocystic disease without atypia (7/17, 41%), in atypical fibrocystic disease (11/11, 100%) and in carcinoma (57/60, 95%). To study the mechanisms involved in mucin gene up‐regulation in breast cancer, we examined baseline, growth‐related and steroid‐induced levels of MUC1, MUC3 and MUC6 in 4 breast cancer cell lines, 2 of which express estrogen receptors. MUC6 levels were up‐regulated at post‐confluence in 2/4 cell lines, whereas no changes were detected for the other mucin genes examined. MUC6 and MUC3 were constitutively expressed, and steroid‐induced, in BT‐474 and MCF‐7 cells, respectively. As a control, pS2 was induced in both cell lines. Our results indicate that (1) MUC6 is overexpressed in breast cancer and in benign breast disease, (2) in vitro, MUC6 and MUC3 are up‐regulated by steroids and (3) abnormal expression of MUC6 in breast cancers may, in part, be explained by hormonal changes associated with tumor development. Int. J. Cancer 77:193–199, 1998.© 1998 Wiley‐Liss, Inc.

CD30 antigen expression in cutaneous inflammatory infiltrates of scabies: a dynamic immunophenotypic pattern that should be distinguished from lymphomatoid papulosis

Background: Expression of CD30 antigen is a distinct marker of lymphocyte activation that was originally described in the Reed–Sternberg cells of Hodgkins disease. The observation of CD30+ cells has been considered a diagnostic feature of cutaneous CD30 lymphoid proliferations. However, CD30 expression has also been reported in some cutaneous benign inflammatory infiltrates.

Differences in the O-Glycosylation Patterns Between Lung Squamous Cell Carcinoma and Adenocarcinoma

Mucins are highly O-glycosylated proteins synthesized by epithelial cells, and their glycosylation patterns can be altered during neoplastic transformation. The 2 types of non-small cell lung cancer (NSCLC) display a similar pattern of mucin gene expression but different reactivity to periodic acid-Schiff diastase, suggesting that a higher number of carbohydrate chains are present in adenocarcinomas. We compared the expression of core (Tn, sialyl-Tn, T) and terminal fucosylated and sialylated (Lewis antigens) carbohydrate structures in lung tumors. Specific antibodies were usedfor immunohistochemical and Western blot assays. Results indicated that core and terminal structures are detected more frequently in adenocarcinoma than in squamous cell carcinoma, except Lewis y, which is expressed strongly in both types of NSCLC. These data suggest that in squamous cell carcinoma and adenocarcinoma, different sets of glycosyltransferases must be expressed and that different posttranslational modifications of the mucin genes can take place in these 2 tumor types.

Recurrent and self-healing cutaneous monoclonal plasmablastic infiltrates in a patient with AIDS and Kaposi sarcoma.

Infection with human immunodeficiency virus (HIV) increases the risk of developing non‐Hodgkin lymphoma. Plasmablastic lymphoma (PBL) is a rare variant of diffuse large cell lymphoma that often involves the oral cavity of HIV+ patients. It is characterized by immunoblastic morphology and plasma cell phenotype. Cutaneous involvement in PBL appears to be rare. We report a 44‐year‐old man with AIDS and Kaposi sarcoma (KS) previously treated with doxorubicin who, following treatment with highly active antiretroviral therapy, developed an erythematous infiltrated nodule on the right arm. Histology showed subcutaneous fat necrosis and clusters of atypical large plasma cells (plasmablastic cells). Immunohistochemistry revealed λ light chain restriction. Epstein–Barr virus (EBV) mRNA was detected by in situ hybridization within the plasmablastic cells. Polymerase chain reaction amplification with specific primers for human herpesvirus 8 (HHV‐8) performed on the skin biopsy specimen detected a specific band. A complete screening (bone marrow biopsy, computed tomographic scan, radiological survey) disclosed no abnormalities. The lesion resolved spontaneously after 3 months. Two years later an infiltrated plaque developed on the abdominal wall. The clinical and histopathological features of this new lesion were similar to those observed 2 years previously. No evidence of extracutaneous involvement was detected. The lesion again resolved spontaneously after 25 days. PBL may be seen in patients with transplants or receiving chemotherapy, but is usually observed in patients with advanced AIDS. The observation of recurrent self‐healing EBV‐ and HHV‐8‐associated cutaneous monoclonal plasmablastic infiltrates, in a patient with AIDS and KS, expands the clinical spectrum of AIDS‐associated plasmablastic lymphoproliferative disorders.

Cutaneous lymphomas showing prominent granulomatous component: clinicopathological features in a series of 16 cases

Background  The presence of a prominent granulomatous tissue reaction in skin biopsies from primary cutaneous or systemic malignant lymphomas with secondary cutaneous involvement is a rare but well‐known phenomenon.

Expression of the Proteoglycans Versican and mel-CSPG in Dysplastic Nevi

Nevi with architectural disorder and cytologic atypia of melanocytes (NAD) (also called dysplastic nevi) have been controversial with regard to their relationship with melanoma risk and to their gradation in 3 degrees of atypia. Versican and the melanoma-associated proteoglycan (mel-CSPG) are 2 major proteoglycans expressed by malignant melanoma, and they have a role in the regulation of cell adhesion, migration, and differentiation. We evaluated the differences in versican and mel-CSPG expression in nevi, NAD with several degrees of atypia, and primary malignant melanoma. Immunoreactivity for versican was negative in benign melanocytic nevi, positive in NAD (ranging from weakly to intensely positive), and intensely positive in malignant melanoma. Immunostaining for mel-CSPG was negative in benign melanocytic nevi and mild to moderately positive in NAD and melanoma. Our results suggest that versican expression may be of value for distinguishing NAD from benign melanocytic nevi and for distinguishing severe NAD from mild and moderate NAD.