No abstract

A monoclonal antibody (MoAb) that defines a novel terminal B-cell- restricted antigen, termed HM1.24, was developed against a human plasma cell line. The MoAb, designated anti-HM1.24, reacted with five different human myeloma cell lines, as well as with monoclonal neoplastic plasma cells obtained from the bone marrow or peripheral blood of patients with multiple myeloma or Waldenstrom's macroglobulinemia. The HM1.24 antigen was also expressed by mature Ig- secreting B cells (plasma cells and lymphoplasmacytoid cells) but not by other cells contained in the peripheral blood, bone marrow, liver, spleen, kidney, or heart of normal individuals or patients with non- plasma-cell-related malignancies. The anti-HM1.24 MoAb bound to human myeloma RPMI 8226 cells with an affinity constant of 9.2 x 10(8) M-1, indicating approximately 84,000 sites/cell. By immunoprecipitation assay under reducing conditions, this MoAb identified a membrane glycoprotein that had a molecular weight of 29 to 33 kD. Our studies indicate that the HM1.24-related protein represents a specific marker of late-stage B-cell maturation and potentially serves as a target antigen for the immunotherapy of multiple myeloma and related plasma cell dyscrasias.

To elucidate the molecular basis for endocrine tumorigenesis, ras mutations in human endocrine tumors were analyzed using polymerase chain reaction‐single strand conformation polymorphism (PCR‐SSCP) analysis. Mutations of the H‐, K‐, N‐ras genes were examined in genomic DNAs from 169 successfully amplified primary endocrine tumors out of 189 samples. Four out of 24 thyroid follicular adenomas analyzed contained mutated N‐ras codon 61, and one contained the mutated H‐ras codon 61. One of the 19 pheochromocytomas revealed mutation of the H‐ras codon 13. No mutations of the ras gene were detected in pituitary adenomas, parathyroid tumors, thyroid cancers, endocrine pancreatic tumors, and adrenocortical tumors. Based on these findings we conclude that activation of the ras gene may play a role in the tumorigenesis of a limited number of thyroid follicular adenomas and pheochromocytomas, and that mutation of the ras gene is not frequent in other human endocrine tumors.

Prostate cancer is a polygenic disease with a large heritable component. A number of common, low-penetrance prostate cancer risk loci have been identified through GWAS. Here we apply the Bayesian multivariate variable selection algorithm JAM to fine-map 84 prostate cancer susceptibility loci, using summary data from a large European ancestry meta-analysis. We observe evidence for multiple independent signals at 12 regions and 99 risk signals overall. Only 15 original GWAS tag SNPs remain among the catalogue of candidate variants identified; the remainder are replaced by more likely candidates. Biological annotation of our credible set of variants indicates significant enrichment within promoter and enhancer elements, and transcription factor-binding sites, including AR, ERG and FOXA1. In 40 regions at least one variant is colocalised with an eQTL in prostate cancer tissue. The refined set of candidate variants substantially increase the proportion of familial relative risk explained by these known susceptibility regions, which highlights the importance of fine-mapping studies and has implications for clinical risk profiling.

A retrospective review of the clinical and pathologic features of 61 cases of penile squamous cell carcinoma (SCC), all treated by primary surgical resection at the Memorial Sloan Kettering Cancer Center during the period 1949-1992, was undertaken. Inguinal lymph node dissection material was evaluated in 40 cases. All carcinomas were of squamous cell type and were classified as follows: usual type, 36 cases (59%); papillary, not otherwise specified (NOS), 9 cases (15%), basaloid, 6 cases (10%); warty (condylomatous), 6 cases (10%); verrucous, 2 cases (3%), and sarcomatoid, 2 cases (3%). A high rate of nodal metastasis and poor survival were found for the basaloid and sarcomatoid neoplasms (5 of 7 patients with metastasis, 71%, and 5 of 8 dead of disease, 63%). Only 1 patient with a verruciform tumor (defined as a tumor of nonspecific papillary, warty, or verrucous type) had inguinal node metastasis and none died from penile cancer. An intermediate rate of metastasis and mortality (14 of 26, 54%, and 13 of 36, 36%, respectively) was found for typical SCC. Penile carcinomas are morphologically heterogeneous, and there is a correlation of histologic type and biologic behavior. This mandates accurate histologic subtyping by the pathologist.

No abstract

SummaryThis study explored the use of interleukin 2 (I1,2) and interferon ~/(IFN-3') gene-modified tumor cells as cellular vaccines for the treatment of bladder cancer. The mouse MBT-2 tumor used is an excellent model for human bladder cancer. This carcinogen-induced tumor of bladder origin resembles human bladder cancer in its etiology and histology, and responds to treatment in a manner similar to its human counterpart. Using retroviral vectors, the human I1,2 and mouse IFN-qr genes were introduced and expressed in MBT-2 cells. The tumor-forming capacity of the cytokine gene--modified MBT-2 cells was significantly impaired, since no tumors formed in mice injected intradermaUy with either II.2-or IFN-y-secreting cells, using cell doses far exceeding the minimal tumorigenic dose of parental MBT-2 cells. Furthermore, mice that rejected the IL-2-or IFN-3,-secreting tumor cells became highly resistant to a subsequent challenge with parental MBT-2 cells, but not to 38C13 cells, a B cell lymphoma of the same genetic background. To approximate the conditions as closely as possible to the conditions prevailing in the cancer patient, inactivated cytokine-secreting cells were used to treat animals bearing tumors established by orthotopic implantation of MBT-2 cells into the bladder wall of the animal. Treatment of mice carrying a significant tumor burden with I1.2-secreting MBT-2 cells had a significant inhibitory effect on tumor progression with extended survival. Moreover, in 60% of the mice the tumor regressed completely and the animals remained alive and free of detectable tumor for the duration of the observation period. Treatment of tumor-bearing animals with I1.2-secreting MBT-2 cells was superior to the use of cisplatin, a chemotherapeutic agent used in the treatment of bladder cancer. The therapeutic effect of IFN-3,-secreting cells was minimal and treatment with unmodified MBT-2 cells had no effect on tumor growth or survival, showing that the parental MBT-2 cells were nonimmunogenic in this experimental setting. Most importantly, mice that exhibited complete tumor regression after treatment with I1.2-secreting MBT-2 cells became resistant to a subsequent challenge with a highly tumorigenic dose of parental MBT-2 cells, indicating that long-term immunological memory was established in the "cured" mice.

Abstract.We immunohistochemically investigated the localization of activin A and follistatin in various human tissues with specific antibodies to recombinant human (rh-) activin A and rh-follistatin.