Co-expression of parathyroid hormone and chromogranin A in secondary hyperparathyroidism: a functional marker for secretory activity of hyperplastic nodules

The relationship between secretion of parathyroid hormone (PTH) and biologic characteristics, including cell proliferation or monoclonality, is not yet fully understood. To evaluate secretory activity of glands or nodules histopathologically, we focused on the co-expression of chromogranin A (CgA) and parathyroid hormone (PTH) in each gland or nodule. A total of 55 glands from 38 patients with normal parathyroid glands, hyperplastic glands (diffuse and nodular) and primary adenomas were compared. Co-expression of PTH and CgA was decreased to 44.4% in diffuse hyperplastic glands, and to 39.6% in 91 hyperplastic nodules, in contrast to normal glands and primary adenomas that showed constant co-expression of PTH and CgA. Immunohistochemical study of PTH showed a coarse granular pattern predominantly in PTH-positive/CgA-positive nodules, and a dot-like pattern mainly in PTH-positive/CgA-negative nodules. Laser scanning microscopy and immunoelectron microscopy confirmed that a dot-like pattern is based on a positive reaction of PTH at the Golgi apparatus. MIB-1 LI was 12.6 +/- 11.6 in PTH-positive/CgA-positive, and 19.3 +/- 27.3 in PTH-positive/CgA-negative nodules. In conclusion, a combination of PTH and CgA could provide more information about the physiologic state of secretory activity of each nodule than does the simple observation of PTH immunoreactivity.     

Reversal of drug resistance mediated by hammerhead ribozyme against multidrug resistance-associated protein 1 in a human glioma cell line

We examined the effects of suppressing multidrug resistance-associated protein 1 (MRP1) gene expression in a human glioma cell line U87MG. Hammerhead ribozymes, designed to cleave MRP1 mRNA (alphaMRP1-Rz), were transfected into the U87MG cells. The U87MG/alphaMRP1-Rz cells were significantly sensitive to nitrosourea (ACNU) and doxorubicin (DOX) compared with the U87MG cells (p<0.01 and p<0.05, respectively, unpaired t-test). There was no significant difference in the expression of other human genes between the U87MG/alphaMRP1-Rz and controls by cDNA array. The hammerhead ribozyme-mediated specific suppression of MRP1 was sufficient to reverse the resistance of ACNU and DOX in the human glioma cell line.     

Heterogeneous gene alterations in primary breast cancer contribute to discordance between primary and asynchronous metastatic/recurrent sites: HER2 gene amplification and p53 mutation

The aim of the present study was to clarify differences in genetic events between primary breast cancers and asynchronous metastatic/recurrent lesions, by examining HER2 gene amplification and p53 mutation. The subjects were 44 breast cancer patients with asynchronous metastasis or recurrence. Synchronous metastases were excluded. HER2 overexpression and gene amplification were examined using immunohistochemistry and fluorescent in situ hybridization (FISH). P53 point mutation was examined by immunohistochemistry, laser-captured microdissection, PCR-single-strand conformation polymorphism, and a direct sequencing method. Immunohistochemistry showed that, for HER2, p53, ER and PgR, discordance rates between primary and recurrent tumor were 2 (4.5%), 1 (2.3%), 7 (15.9%) and 10 (22.7%), respectively. Two primary tumors with discordant HER2 overexpression were composed of at least two populations of carcinoma cells, with and without HER2 gene amplification. Distribution of HER2 gene amplification was consistent with protein overexpression. Corresponding recurrent tumors consisted of carcinoma cells without HER2 gene amplification. Of 6 recurrent tumors in which the primary carcinoma had a p53 point mutation, 3 tumors had identical mutations, 1 tumor had a different point mutation, and 2 tumors had no mutation. It was suspected that the latter 3 recurrent tumors comprised a minor component of the primary tumor. In the present study, we examined a large series of asynchronous recurrent tumors. A limited number of these tumors showed discordance between primary and recurrent tumors. Detailed observations revealed that cell populations present in recurrent tumors were also present in the primary tumors, although they comprised a minor component of the primary tumor. Heterogeneity of the primary tumor apparently contributed to discordance.     

Undifferentiated spindle and giant cell carcinoma of the common bile duct

Undifferentiated spindle and giant cell carcinoma of the common bile duct has not been reported previously. We present here a case of 71-year-old man with the undifferentiated spindle and giant cell carcinoma of the common bile duct, including immunohistochemical findings. A nodular infiltrating tumor was located at the lower portion of the extrahepatic bile duct, and measured 1.2 x 0.6 cm in size. Histologically, the tumor was composed of proliferated sarcomatoid spindle tumor cells. Numerous multinucleated giant cells were intermingled with the sarcomatoid spindle tumor cells. Immunohistochemically, the tumor cells were positive for both cytokeratin and vimentin. We speculated that the tumor originated from epithelial cells, and showed sarcomatoid neplastic changes.     

Immunoelectron microscopic demonstration of glycoprotein subunits in the FSH producing pituitary adenomas

Immunoelectron microscopic observations disclosed the presence of FSH alpha, beta subunits in secretory granules and rough endoplasmic reticulum (RER). Golgi saccules were consistently negative. The presence of these subunits in secretory granules which were located in the vicinity of RER or perinuclear spaces (PNS) suggested the possible formation of secretory granules in RER or PNS. The tumor cells showed heterogeneity in size and immunoreactivity of the secretory granules but non-neoplastic cells showed uniformity in these aspects.     

Loss of heterozygosity alterations associated with progesterone therapy in endometrial hyperplasia and adenocarcinoma

Loss of heterozygosity (LOH) was analyzed in four patients with endometrial hyperplasia (EH) with atypia (two patients) and without atypia (two patients) and in five patients with endometrial adenocarcinoma (EAC) to clarify the clinicopathologic relationship between genetic alterations and hormone therapy. Each patient was initially administered high-dose medroxyprogesterone acetate (MPA) as a uterine-sparing treatment. The five microsatellite markers used to analyze LOH were at chromosomal loci 8p22.1, 8p21, 8p21.3, 8p22, and 8p22. DNA was extracted from paraffin-embedded sections before, during, and after MPA therapy using laser capture microdissection. As a result, LOH was more frequently detected after MPA therapy (overall ratios were 16, 17, and 29% before, during, and after MPA therapy, respectively). LOH is more easily detected in EH loci than in EAC loci before MPA. For EAC, initial LOH detection on chromosome 8 may be related to an incomplete response to MPA, but negative LOH does not guarantee a favorable treatment outcome. For EH or atypical endometrial hyperplasia, it is unknown whether LOH alteration associated with MPA therapy is related to atypia of the disease.     

Rectal carcinoid tumor metastasizing to the thyroid and pancreas. An autopsy case exploiting immunohistochemistry for differentiation from tumors involving multiple endocrine organs

A 58-year-old male patient with rectal carcinoid tumor is presented. The tumor extensively involved the lymph nodes and liver, and multiple tumors were also recognized in the pancreas and thyroid. Grossly, it was uncertain whether the latter were metastases from the rectal carcinoid or all were coincident primary tumors involving multiple endocrine organs, so-called multiple endocrine neoplasia (MEN) syndrome. Histologic, histochemical and electron microscopic examinations of the tumors in both the pancreas and thyroid showed similar features to those of the rectal carcinoid. The neoplastic cells in all involved organs commonly expressed positive immunoreactivity for somatostatin, but negativity for carcinoembryonic antigen, calcitonin, calcitonin gene-related peptide, thyroglobulin, insulin, glucagon and pancreatic polypeptide. These immunohistochemical results confirmed that the tumors observed in multiple endocrine organs were indeed metastatic from the rectal carcinoid, rather than being a new combination of MEN syndrome. Some neuroendocrine tumors may develop widespread metastasis, sometimes creating problems with differentiation from multiple primary endocrine tumors. Immunohistochemistry may be of great help in setting this issue.