Expression of CXCL13 by neoplastic cells in angioimmunoblastic T-cell lymphoma (AITL): a new diagnostic marker providing evidence that AITL derives from follicular helper T cells.

Angioimmunoblastic T-cell lymphoma (AITL) represents a distinct entity among peripheral T-cell lymphomas (PTCLs). The cellular origin of AITL remains unknown, although a possible derivation from follicular helper T cells (TFH) has been suggested based on the CD4/Bcl-6 phenotype. It has been recently shown that expression of CXCL13, a chemokine critically involved in B-cell migration into germinal centers, is characteristic of TFH cells, as compared with other T helper subsets. We compared CXCL13 expression in 29 AITLs, 20 PTCLs, unspecified, 10 anaplastic large cell lymphomas (ALCL), and 4 other PTCLs. We showed that CXCL13 is expressed by AITL (29 of 29, 100%) and a subset of PTCL, unspecified (6 of 20, 30%), which all showed borderline features with AITL, but in only 1 of 10 (10%) ALCLs, and 0 of 4 other PTCLs. Two-color immunostainings further showed that CXCL13 was found in the cytoplasm of atypical CD5-positive T cells that expressed CD10. We conclude that CXCL13 expression is a common characteristic of AITL, which can help to delineate the morphologic spectrum of the disease, and further supports its derivation from TFH cells. CXCL13 expression may also provide an additional useful tool for the diagnosis of AITL.

Non-Leydig sex-cord tumors of the testis. The place of immunohistochemistry in diagnosis and prognosis. A study of twenty cases.

In 20 sex-cord tumors of the testes, we investigated immunohistochemistry as a possible method for histopathological diagnosis and evaluation of prognosis. We examined the following molecules: inhibin, CD99, cytokeratin, vimentin, MIB-1, estrogen receptors and progesterone receptors. These tumors of the testes comprised 18 Sertoli cell tumors (ScT) and two undifferentiated sex-cord tumors (USCT). Four tumors have been considered as malignant, because of metastatic spread. Inhibin was expressed by the tumor cells in 80% of sex cord tumors, without any correlation to the degree of differentiation and only in 25% of the malignant cases. Inhibin is a specific marker for sex-cord tumors of the testis and is particularly useful for the diagnosis of USCT. CD99, vimentin, keratin, progesterone and estrogen receptors were expressed in, respectively, 60%, 75%, 35%, 65% and 20% of cases; 95% expressed one of the three following markers: inhibin, CD99 or vimentin. Proliferation index MIB-1 was equal to or higher than 30% in the four malignant cases versus less than 20% in other cases. Lack of inhibin expression and a proliferation index (MIB-1) greater than 30% should be considered as a criterion in favor of malignancy.

Endocervicosis of the urinary bladder. Immunohistochemical comparative study between a new case and normal uterine endocervices.

Endocervicosis of the urinary bladder is a rare non-neoplastic condition characterized by endocervical-type glands deeply situated in the urinary bladder wall of women of reproductive age. We compared the immunohistochemical phenotype of a case of endocervicosis in a 35-year-old woman with four normal uterine endocervices. We tested antibodies known as reactive in the uterus and not mentioned or negative in the urothelium (HBME-1, estrogen receptor (ER), progesterone receptors (PR), DF3, Chromogranin). The proliferative index was assessed with MIB-1 antibody. Endocervicosis glands displayed stronger expression of HBME-1, ER and PR than normal endocervices, while the urothelium was negative. There was no difference in DF3 expression. The number of Chromogranin-positive cells was higher in endocervicosis than in the endocervices. The proliferative index was higher in the endocervicosis glands (15%) than in the normal endocervices (mean 3%), but was within the normal range established for endocervical glands. Our results confirm the endocervical nature of endocervicosis and constitute further arguments for the mullerian origin hypothesis. The only modestly increased proliferative index, as compared to endocervical malignancies, is consistent with a benign diagnosis.

Heterogeneous metastasis efficiency of isogenic orthotopic colon cancer xenografts reveals distinctive gene expression profiles.

Hepatic and lung metastases are the leading causes of mortality and major indicators of aggressiveness in colorectal cancer. The underlying molecular mechanisms contributing to the development of metastasis are still unclear. Here, we designed a novel approach to explore gene expression profiles associated with metastasis in human colorectal cancer (hCRC). A series of ten isogenic tumors from three different hCRC models were orthotopically implanted into nude mice. In these series, we analyzed the contribution of dynamic heterogeneity, independently of any intrinsic gene expression program predictive of metastasis. When screened for the presence of disseminated tumor cells in the lung and liver, as the most common host tissues for hCRC metastases, both high- and low-metastatic efficient tumors were found among these isogenic orthotopic series. The metastasis-specific cDNA macroarray analysis of 96 genes, in both tumor populations for each of the three hCRC models, characterized a common differential gene expression within a small group of genes. Our results suggest that, independently of a gene expression profile predictive of metastasis, the progressive acquisition of additional alterations occurs during hCRC tumorigenesis. This dynamic process might determine tumor progression, namely the metastasis dissemination.

Gefitinib and chemotherapy combination studies in five novel human non small cell lung cancer xenografts. Evidence linking EGFR signaling to gefitinib antitumor response.

The epidermal growth factor receptor (EGFR) signaling pathway is often activated in NSCLC, and thus represents a promising therapeutic target. We studied the antitumor activity of gefitinib (Iressa), an orally active EGFR-tyrosine kinase inhibitor, alone and in combination with standard chemotherapy in 5 recently established human NSCLC xenografts with wild-type EGFR. Mice were treated with 2 protocols of chemotherapy based on cisplatin (CDDP) combined with either gemcitabine (GEM) or vinorelbine (VNR). Gefitinib alone significantly inhibited tumor growth (TGI) in 4 of the 5 tumor xenografts (mean TGI of 58%, range: 25-70%). CDDP+VNR alone failed to achieve any significant responses, while CDDP+GEM achieved significant responses in 2 xenografts (TGI of 93 and 47%). Addition of gefitinib to CDDP+GEM potentialized chemotherapy in the 3 CDDP+GEM-resistant xenografts, but did not potentialize the CDDP+VNR combination. The effect of gefitinib treatment on the activity of extra cellular-regulated kinase (Erk), Akt, JNK and p38 kinases was assessed in IC9LC11 and IC1LC131, two NSCLC xenografts selected for their sensitivity and resistance to gefitinib, respectively. In IC9LC11, gefitinib strongly inhibited Erk, Akt and Jnk phosphorylation, but P38 remained active. Inversely, in IC1LC131, Erk and Akt pathways remained active, while Jnk and P38 pathways were inhibited by gefitinib. The data indicate that the antitumor activity of gefitinib in NSCLC, alone or in combination with chemotherapy, is tumor-dependent and is influenced by downstream signaling events independent of EGFR status.

Activity of docetaxel with or without estramustine phosphate versus mitoxantrone in androgen dependent and independent human prostate cancer xenografts.

PURPOSE: Prostate cancer is known to be refractory to chemotherapy with only mitoxantrone showing some benefit. Recent clinical data indicate the antitumoral efficacy of taxanes alone or combined with estramustine phosphate. We compared the response to these treatments of hormone dependent and independent human prostate cancer xenografts. MATERIALS AND METHODS: PAC120, an androgen dependent human prostate cancer xenograft, and several HIDs, which are androgen independent variants, were established in nude mice. Human gene expression was determined by semiquantitative reverse transcriptase-polymerase chain reaction. Androgen deprivation was achieved by surgical castration. Tumor bearing mice received 20 mg./kg. docetaxel on day 2, 1 mg./kg. hydrocortisone on days 1 to 3, 4 mg./kg. estramustine phosphate on days 1 to 4 or 1 mg./kg. mitoxantrone on day 1 by the intraperitoneal route for 3-week cycles. Relative tumor volume and growth delay were evaluated. Histological examination of tumors was done before and after treatment. RESULTS: Mitoxantrone transiently decreased the growth rate of HID xenografts but did not affect that of PAC120. Estramustine phosphate alone inhibited the growth of PAC120 but not that of HID variants. Docetaxel inhibited the growth of all prostate cancer xenografts (PAC120 and HIDs) and increased survival. PAC120 showed distinct response patterns during prolonged treatment. Efficacy was significantly decreased by splitting docetaxel into 2 doses given at a 7-day interval (p = 0.01). The docetaxel effect was potentiated by estramustine phosphate in 1 of the 2 HID variants tested. In castrated mice docetaxel induced a greater growth delay than in intact male mice (p = 0.01). High Her2/neu and beta2-tubulin transcripts were detected in all samples. Prostate specific antigen, androgen receptor and multidrug related protein-1 mRNA did not correlate with the drug response, while CYP3A4 mRNA inversely correlated with the response. Docetaxel treated tumors had an increased number of mitotic cells with centrosome alterations and multinuclei, an increased number of Ki67 labeled cells and a strong decrease in beta-tubulin without evidence of apoptosis. CONCLUSIONS: Docetaxel showed a significant antitumoral effect on hormone dependent and tumors, which was largely superior to that of mitoxantrone. Estramustine phosphate alone had a modest effect. The drug response was associated with high Her2/neu expression, low CYP3A4 expression and the induction of numerous mitotic abnormalities.