Upregulation of RET induces perineurial invasion of pancreatic adenocarcinoma.

Tumor spread along nerves, a phenomenon known as perineurial invasion, is common in various cancers including pancreatic ductal adenocarcinoma (PDAC). Neural invasion is associated with poor outcome, yet its mechanism remains unclear. Using the transgenic Pdx-1-Cre/KrasG12D /p53R172H (KPC) mouse model, we investigated the mechanism of neural invasion in PDAC. To detect tissue-specific factors that influence neural invasion by cancer cells, we characterized the perineurial microenvironment using a series of bone marrow transplantation (BMT) experiments in transgenic mice expressing single mutations in the Cx3cr1, GDNF and CCR2 genes. Immunolabeling of tumors in KPC mice of different ages and analysis of human cancer specimens revealed that RET expression is upregulated during PDAC tumorigenesis. BMT experiments revealed that BM-derived macrophages expressing the RET ligand GDNF are highly abundant around nerves invaded by cancer. Inhibition of perineurial macrophage recruitment, using the CSF-1R antagonist GW2580 or BMT from CCR2-deficient donors, reduced perineurial invasion. Deletion of GDNF expression by perineurial macrophages, or inhibition of RET with shRNA or a small-molecule inhibitor, reduced perineurial invasion in KPC mice with PDAC. Taken together, our findings show that RET is upregulated during pancreas tumorigenesis and its activation induces cancer perineurial invasion. Trafficking of BM-derived macrophages to the perineurial microenvironment and secretion of GDNF are essential for pancreatic cancer neural spread.

The hormonal milieu in early stages of bone cell differentiation modifies the subsequent sex-specific responsiveness of the developing bone to gonadal steroids.

We have established previously that rat bone tissue, as well as rat and human-derived bone cells in culture, show a sex-specific response to gonadal steroids in stimulation of the specific activity of the BB isozyme of creatine kinase (CK) and DNA synthesis. This response could be modified by manipulation of the endocrine environment during early stages in rat development. To further examine the influence of changing hormonal steroid milieu and vitamin D status on the action of gonadal steroids in developing bone tissue, we used two models of ectopic bone formation: demineralized tooth matrix (DTM) implanted under the skin, and femoral bone marrow (BM) transplanted under the kidney capsule of a syngeneic recipient mouse. The response to gonadal steroids in ossicles developed from implanted DTM depended on the recipient's gender; injection of estradiol 17beta (E2; 5 microg) into young female mice 21 days after DTM implantation increased, 24 h later, CK activity in the newly formed ossicles by approximately 60%, whereas injection of dihydrotestosterone (DHT; 50 microg) had no effect on CK activity. In contrast, in male mice, DHT but not E2 increased CK activity in the ossicles by approximately 50%. This sex-specific response was abolished in gonadectomized mice resulting in a similar response of the ossicles to both E2 and DHT. When DTM was implanted into vitamin D- deficient female mice, there was a lower basal CK activity and a significantly diminished response to E2 in the newly formed bone tissues. When BM, which contains mesenchymal and stromal cells and committed osteoprogenitor cells, was transplanted into 6-week-old intact or gonadectomized female or male mice, the response of the newly formed bone ossicles, 21 days after transplantation, to E2 or to DHT was according to the gender of the donor. Bone formed from BM obtained from female mice responded to E2 only and those formed from male BM responded to DHT only. Ossicles developed from BM obtained from gonadectomized mice showed lack of response to either gonadal steroid. Furthermore, only approximately 25% of the BM transplants obtained from castrated (CAST) male donors developed into ossicles. Ossicles formed from BM obtained from vitamin D-deficient female donors showed lack of response to gonadal steroids. These findings suggest that the manipulation of the hormonal milieu in early stages of the differentiation sequence of bone cells modifies the subsequent selective responsiveness of the developing bone tissue to gonadal steroids.

Absence of RBM expression as a marker of intratubular (in situ) germ cell neoplasia of the testis.

RBM (RNA-binding motif) protein is a marker of male germ cells. This protein is encoded by the Azoospermia factor region-b (AZF-b) of the human Y chromosome and is expressed exclusively in the male germ cell line, that is, spermatogonia, spermatocytes, and round spermatids. The authors analyzed the expression of the RBM gene in germ cell tumors and in the seminiferous tubules in the vicinity of these tumors to identify the presence of IGCN. Sections from testicular germ cell tumors of 21 patients were stained with anti-RBM antibody by using an immunohistochemical method. Distal tubules showing spermatogenesis were immunopositive for RBM protein. All of the germ cell tumors studied were completely immunonegative for RBM. Defined areas of IGCN also showed an absence of RBM expression. Tubules with spermatocyte-like cells, which were expected to express RBM, did not express this protein. This result enabled the identification of tubules as being IGCN. RBM is a novel marker consistently expressed in normal male germ cells but not in malignant germ cell tumors or IGCN. Thus, the absence of RBM expression in germ cells provides a new diagnostic tool of preinvasive malignancy of the testis.

Primary angiosarcoma of the ovary: a clinicopathologic, immunohistochemical and electronmicroscopic study.

The present report of a 25 year old woman with a primary ovarian angiosarcoma is supplemented by histochemical and ultrastructural studies and reviews the literature of this extremely rare neoplasm. Since this ovarian tumor, especially in young women, may constitute a diagnostic pitfall, problems relating to differential diagnosis are emphasized. Although the origin of this neoplasm appears to occur most likely from the rich ovarian vasculature, other less conventional histogenetic theories such as a possible origin in mixed mullerian tumor, in teratoma or in other ovarian germ cell tumors have also been proposed and are considered in this paper.

Nuclear localization of beta-catenin and plakoglobin in primary and metastatic human colonic carcinomas, colonic adenomas, and normal colon.

Beta-catenin is a cytoskeleton-associated signaling molecule shown to be elevated in various carcinomas but mostly in colon cancer owing to its impaired degradation. In contrast, its close homologue plakoglobin was shown to suppress the tumorigenicity of certain tumor cells. In the present study, we have used a semiquantitative immunohistochemical approach to evaluate the extent of nuclear localization of beta-catenin in human colonic adenocarcinomas and adenomas and compared it to the distribution of plakoglobin in the same tissues. We show that beta-catenin accumulates in the nuclei of the epithelium of primary and metastatic colonic adenocarcinoma as well as in colonic adenomas. In contrast, nuclear plakoglobin levels in these tissues were low, even compared to those found in epithelial cells of normal colon. These results support the view that the increase in beta-catenin levels in colon cancer cells occurs early in the tumorigenic process, leading to its nuclear localization, not only in invasive adenocarcinoma, but also in colonic adenoma with mild dysplasia.

Intratubular germ cell neoplasia: associated infertility and review of the diagnostic modalities.

The incidence of testicular neoplasia has increased, and its early detection has become a pressing clinical issue. The strong association between male subfertility and risk of testicular neoplasia is consistent with the existence of common pathogenetic factors. Most forms of testicular germ tumors are believed to stem from a common precursor, intratubular germ cell neoplasia (ITGCN), also known as testicular carcinoma in situ. Identification of ITGCN cells in testicular biopsies, however, is a diagnostic challenge and markers are sorely needed to assist in the accurate identification of the lesion.

Primary papillary serous carcinoma of the peritoneum in a man.

BACKGROUND: Primary papillary serous carcinoma of the peritoneum is a well-known entity in women. The tumour is derived from the extraovarian mesothelium and the pelvis and lower abdomen mesothelia. The treatment strategies are similar to ovarian serous papillary carcinoma. PATIENTS AND METHODS: A case of primary serous papillary carcinoma of the peritoneum in a man is presented. The patient, 53 years old, died 2 months after diagnosis. RESULTS: The histologic and immunohistochemical studies of the tumour will be presented. These studies, made during lifetime and at autopsy of the patient, confirm a diagnosis of primary serous papillary carcinoma of the peritoneum. CONCLUSIONS: primary serous papillary carcinoma of the peritoneum can occur in men, and should be considered in the differential diagnosis in cases of abdominal carcinomatosis of unknown origin. Treatment options remain to be determined.

Protein phosphatase 2Calpha expression in normal human tissues: an immunohistochemical study.

Protein phosphatase (PP2Calpha) is a member of the mammalian serine threonine-specific protein phosphatases family. We produced monoclonal antibodies against the recombinant PP2Calpha and evaluated the immunoreactivity of normal human tissues. The reactivity was strong in normal skin, the digestive tract, lung, kidney, breast, prostate, endocrine glands, and brain, while it was moderate in the ovary, testis, and liver. Epithelial cells revealed high levels of PP2Calpha expression, but stromal cells, including fibroblasts and endothelial cells, showed no or little PP2Calpha expression. Given the broad reactivity in endocrine and secreting epithelial cells, we propose that PP2Calpha expression might contribute to secretory cell function.

Neuronal-binding antibodies from patients with antiphospholipid syndrome induce cognitive deficits following intrathecal passive transfer.

Antiphospholipid antibodies (aPL) have been suggested to play a role in causing cognitive and behavioral impairments. In the present study we investigated the pathogenic potential of aPL by intracerebro-ventricular (ICV) administration of immunoglobulins (IgG) from patients with antiphospholipid syndrome (APS). IgG, purified from the sera of four APS patients, was tested for binding to normal mouse brain by immunohistological staining. These IgG (7.5 microg) were injected ICV unilaterally to male C3H mice. Mice injected with IgG purified from pooled sera derived from healthy subjects served as controls. The mice were examined neurologically for motor function and coordination, and cognitively in a Morris water maze. The cognitive tests were performed with the experimenter blinded to the treatment. The performance of the mice in four separate experiments was compared by analysis of variance with repeated measures. IgG from one APS patient was found to bind best to neuronal structures in the hippocampus and cerebral cortex. Mice (n = 43) injected with this IgG performed worse in the water maze compared to the controls (n = 45) with significant effects of the aPL IgG on the overall performance of the mice (treatment, P < 0.03), on learning throughout the experiment (treatment x day, P < 0.02) and on short term memory (treatment x day xtrial, P < 0.002). IgG injected from two of the three other patients also bound specifically to mouse brain neurons and produced an impairment in performance of the water maze. These results support the hypothesis that aPL that gain access to the central nervous system may play a direct role in the pathogenesis of neurological manifestations of APS.