Pure non-gestational choriocarcinoma arising in the ovary.

Non-gestational choriocarcinoma (NGCO) is a rare primary ovarian cancer with poor prognosis. It is important to distinguish it from gestational ovarian choriocarcinoma (GCO), because there are different treatment options. However, it is difficult to distinguish the two types by routine histologic, ultrastructural, or immunohistochemical examination. The authors present NGCO in a 41-year-old woman, which was confirmed by DNA polymorphism analysis. All tested microsatellite markers had identical DNA profiles with the same allelic sizes between tumor and normal myometrium of the patient, indicating that both tissues originated from the same person. The results confirmed that the tumor was non-gestational in origin. Although the tumor was large, the authors performed hand- assisted laparoscopic surgical (HALS) staging. After three cycles of combination chemotherapy and surgery, the patient has not had any evidence of disease 48 months after treatment. This case demonstrates the usefulness of HALS staging and DNA polymorphism analysis in NGCO.

Molecular and physical characteristics of squid (Todarodes pacificus) skin collagens and biological properties of their enzymatic hydrolysates.

The physicochemical properties of squid skin collagens and biological activity of their enzymatic hydrolysates were determined to produce more value-added materials. The amino acid compositions of the inner and outer squid skin collagens were similar, but distinct from that of bovine tendon collagen in respect to the higher levels of aspartic acid, arginine, threonine, and serine, and of the lower levels of alanine, proline, and hydroxyproline. SDS-PAGE patterns suggested that squid skin collagen consisted of at least 2 different polypeptides (alpha1 and alpha2 chains) and their cross-linked chains. The molecular weights of alpha1 and alpha2 chains of bovine tendon collagens were higher than those of the corresponding alpha1 and alpha2 chains of squid skin collagens. The denaturation temperatures of inner and outer skin collagens were 27.1 and 27.3 degrees C, respectively, which were about 9 degrees C lower than that of bovine tendon collagen. Water holding capacities of inner and outer squid skin collagens were relatively similar, but were significantly greater than that of bovine tendon collagen. The maximum hydrolysis of squid skin collagens was obtained as follows: for outer skin collagen, enzyme concentration, 3.5%; hydrolysis time, 83 min; pH 7.0; hydrolysis temperature, 60 degrees C, whereas for inner skin collagen, enzyme concentration, 3.2%; hydrolysis time, 83 min; pH 7.0; hydrolysis temperature, 60 degrees C. The enzymatic hydrolysates of outer and inner skin collagens were separated by Sephacryl S-100 column, resulting in the production of 3 fractions (F1, F2, and F3). F3 fraction exhibited higher antioxidant, tyrosinase inhibitory, and antielastase activities than the other fractions.

Lysis of ras oncogene-transformed cells by specific cytotoxic T lymphocytes elicited by primary in vitro immunization with mutated ras peptide.

Ras protooncogenes are activated by characteristic point mutations in a wide variety of malignancies. The expressed p21ras proteins are oncogenic by virtue of single substituted amino acids, usually at position 12 or 61 of the 189-residue p21ras protein. In the current study, the ability of class I major histocompatibility complex (MHC)-restricted T cells to recognize the altered segment of a transforming p21ras protein and to lyse cells transformed by the corresponding ras oncogene was examined. Synthetic ras peptides encompassing the common activating substitution of leucine for glutamine at position 61 were constructed with an amino acid motif appropriate for binding to the H-2Kb murine class I MHC molecule. Cytotoxic T lymphocytes (CTL) specific for bound ras leucine 61 peptide were elicited by in vitro immunization of normal lymphocytes with synthetic peptides. The ras peptide-induced CTL specifically lysed syngeneic fibroblasts transformed by an activated ras gene encoding oncogenic p21ras protein containing the same single amino acid substitution. Thus, in some circumstances, mutated p21ras protein can serve as a tumor-specific antigen.

T-cell immunity to the joining region of p210BCR-ABL protein.

The hallmark of chronic myelogenous leukemia is the translocation of the human c-abl protooncogene (ABL) from chromosome 9 to the specific breakpoint cluster region (bcr) of the BCR gene on chromosome 22. The t(9;22)(q34;q11) translocation results in the formation of a BCR-ABL fusion gene that encodes a 210-kDa chimeric protein with abnormal tyrosine kinase activity. The ABL and BCR genes are expressed by normal cells and thus the encoded proteins are presumably nonimmunogenic. However, the joining-region segment of the p210BCR-ABL chimeric protein is composed of unique sequences of ABL amino acids joined to BCR amino acids that are expressed only by malignant cells. The current study demonstrates that the joining region of BCR-ABL protein is immunogenic to murine T cells. Immunization of mice with synthetic peptides corresponding to the joining region elicited peptide-specific, CD4+, class II major histocompatibility complex-restricted T cells. The BCR-ABL peptide-specific T cells recognized only the combined sequence of BCR-ABL amino acids and not BCR or ABL amino acid sequences alone. Importantly, the BCR-ABL peptide-specific T cells could recognize and proliferate in response to p210BCR-ABL protein. The response of peptide-specific T cells to protein demonstrated that p210BCR-ABL can be processed by antigen-presenting cells so that the joining segment is bound to class II major histocompatibility complex molecules in a configuration similar to that of the immunizing peptide and in a concentration high enough to stimulate the antigen-specific T-cell receptor. Thus, BCR-ABL protein represents a potential tumor-specific antigen related to the transforming event and shared by many individuals with chronic myelogenous leukemia.