Importance of tumor-specific cytotoxic CD8+ T-cells in eradication of a large subcutaneous MOPC-315 tumor following low-dose melphalan therapy.

We have previously demonstrated that depletion of CD8+ T-cells by the use of a monoclonal anti-Lyt-2.2 antibody abolishes the curative effectiveness of low-dose melphalan (L-phenylalanine mustard; L-PAM) therapy for BALB/c mice bearing a large (greater than or equal to 20 mm) s.c. MOPC-315 tumor and extensive metastases (Mokyr et al., Cancer Res., 49: 4597-4606, 1989). Here we show that as a consequence of low-dose L-PAM therapy, CD8+ T-cells accumulate in the s.c. tumor nodules of MOPC-315 tumor bearers. Specifically, an 80-fold increase in the number of CD8+ T-cells was seen within 5 days after the chemotherapy. Treatment of MOPC-315 tumor bearers with low-dose L-PAM in conjunction with monoclonal anti-Thy-1.2 or anti-Lyt-2.2 antibody, in contrast to treatment with monoclonal anti-L3T4 antibody, prevented the appearance of the massive CD8+ T-cell infiltrate in the s.c. tumor nodules. Fresh CD8+ T-cells derived from s.c. MOPC-315 tumor nodules that were regressing as a consequence of low-dose L-PAM therapy exhibited a potent direct lytic activity against the MOPC-315 plasmacytoma in a short-term in vitro assay. The specificity of the lytic activity exhibited by the CD8+ T-cells was illustrated not only by the inability of the CD8+ T-cells to lyse two antigenically unrelated thymomas (the WEHI 22.1 and the EL-4) and a natural killer-sensitive lymphoma (the YAC-1), but also by their relatively weak lytic activity against an antigenically related plasmacytoma (the MOPC-104E). Thus, CD8+ T-cells that infiltrate the s.c. tumor nodules of MOPC-315 tumor bearers following low-dose L-PAM therapy most likely exploit a CTL-type lytic mechanism to eradicate at least part of the large tumor burden not eliminated by the direct antitumor effects of the drug.

Importance of Lyt 2+ T-cells in the curative effectiveness of a low dose of melphalan for mice bearing a large MOPC-315 tumor.

We have previously demonstrated that the curative effectiveness of a low dose (2.5 mg/kg) of melphalan (L-phenylalanine mustard; L-PAM) for mice bearing a large s.c. (approximately 20 mm in diameter) MOPC-315 tumor and extensive metastases requires the participation of T-cell-dependent antitumor immunity in tumor eradication (S. Ben-Efraim et al., Cancer Immunol. Immunother., 15: 101-107, 1983). Here we show that the Lyt 2+ T-cells, and not the L3T4+ T-cells, participate in the cure of such tumor-bearing mice by a low dose of L-PAM. Specifically, depletion of Lyt 2+ T-cells from mice bearing a large MOPC-315 tumor by treatment with monoclonal anti-Lyt 2.2 antibody abolished the curative effectiveness of the low dose of drug. In contrast, depletion of L3T4+ T-cells from mice bearing a large MOPC-315 tumor by treatment with monoclonal anti-L3T4 antibody did not reduce significantly the curative effectiveness of the low dose of drug. Histological examination of tumor nodules on various days following low-dose L-PAM therapy revealed widespread lymphocytic infiltration by Day 5 following the chemotherapy, and this infiltration was drastically reduced when the L-PAM-treated tumor bearers were treated with either anti-Thy 1.2 or anti-Lyt 2.2 antibody but not with anti-L3T4 antibody. The antitumor immunity exhibited by Lyt 2+ T-cells derived from mice which were in the process of eradicating a large MOPC-315 tumor following low-dose L-PAM therapy was exploited successfully to confer systemic antitumor immunity to mice bearing a barely palpable tumor. Specifically, the adoptively transferred Lyt 2+ splenic T-cells, in conjunction with a subcurative dose of L-PAM, brought about the cure of most mice. The Lyt 2+ splenic T-cells from L-PAM-treated MOPC-315 tumor bearers were also found to be capable of exerting a direct potent lytic effect against MOPC-315 tumor cells in an antigen-specific manner. Thus, it is conceivable that the direct cytotoxic activity of Lyt 2+ T-cells for MOPC-315 tumor cells is responsible, at least in part, for the ability of the Lyt 2+ T-cells from L-PAM-treated MOPC-315 tumor bearers to bring about the eradication of the tumor burden not eradicated through the direct antitumor effects of the low dose of drug.

CT of uterine cervical myeloma: case report.

Myelomatous involvement of the uterine cervix is rare and, to our knowledge, has not been reported previously in the radiologic literature. This report describes the computed tomographic (CT) findings and reviews differential diagnostic considerations.

Suppression of antitumor immunity by macrophages in spleens of mice bearing a large MOPC-315 tumor.

We had shown previously that progression of MOPC-315 plasmacytoma growth is associated with an increase in the percentage of macrophages in the spleen as well as a decrease in the ability of tumor-bearer spleen cells to mount an antitumor cytotoxic response upon in vitro immunization. Here we provide evidence that macrophages in the MOPC-315 tumor-bearer spleen are responsible at least in part for the suppression of the generation of antitumor cytotoxicity. Accordingly, removal of most macrophages by depletion of phagocytic cells or Sephadex G-10-adherent cells from spleens of mice bearing a large tumor resulted in augmented antitumor immune potential. Also, Sephadex G-10-adherent spleen cells from tumor-bearing (but not normal) mice drastically suppressed the in vitro generation of antitumor cytotoxicity by normal spleen cells. The suppressive activity of these adherent cells did not reside in contaminating suppressor T cells, since it was not reduced by treatment with monoclonal anti-Thy 1.2 antibody plus complement. The Sephadex G-10-adherent cell population from the tumor-bearer spleen suppressed the in vitro generation of antitumor cytotoxicity against autochthonous tumor cells but not against allogeneic EL4 tumor cells, and hence the suppression was apparently specific. The suppressive activity of the Sephadex G-10-adherent cell population from tumor-bearer spleens was overcome by treatment of the tumor-bearing mice with a low curative dose of cyclophosphamide. This immunomodulatory effect of a low dose of the drug in overcoming the suppression mediated by the Sephadex G-10-adherent cell population enables the effector arm of the immune system of tumor-bearing mice to cooperate effectively with the drug's tumoricidal activity in tumor eradication.

DNA ploidy and proliferation heterogeneity in human prostate cancers.

DNA ploidy determinations have been shown to have clinical application in predicting disease progression, survival, or response to anti-androgen therapies in prostate carcinomas. Since intra-tumor heterogeneity may have a profound effect on DNA measurements, we determined the frequency of DNA ploidy and proliferation (here S-phase fraction) heterogeneity in early prostatic carcinomas, and estimated the potential impact of heterogeneity on predicting disease course, survival, or response to therapy. Using image and flow cytometric analysis of archival, paraffin-embedded prostate tumors, we measured DNA ploidy in individual foci of prostatic carcinoma in stage T1a, T1b and T1c disease. Image analysis studies included the use of Feulgen stained tissue sections, and a comparison of these results with flow cytometric DNA ploidy determinations on nuclei isolated from the same tumor foci. Flow cytometry was also used to measure DNA Index and tumor S-phase fraction, in some cases using multiparameter analysis of isolated nuclei to determine DNA content and the level of the proliferation-associated antigen, p105. Our results indicate that DNA aneuploid foci of prostate carcinoma are infrequently seen in stage T1a disease (13% of the individuals studied), and that the presence of both DNA diploid and aneuploid foci in the same sample is seen in less than 10% of these individuals. Stage T1b and T1c tumors containing only DNA diploid nuclei are seen, though these are likely most common in low volume, low Gleason grade tumors. By using flow cytometry to compare these results with those using image analysis of the same tumor foci, we demonstrated that the majority (> 75%) of these aneuploid tumors are DNA tetraploid. Our data on prostate tumor S-phase fractions indicate that DNA diploid tumors generally have a lower S-phase than DNA aneuploid foci (including comparisons of DNA diploid and aneuploid foci in the same prostate tumor). These results support the model that early prostate tumors are DNA diploid and have a low S-phase, and that these tumors likely evolve to DNA tetraploid tumors with a similar low S-phase fraction.

Thrombospondin 1 synthesis and function in wound repair.

Thrombospondin 1 (TSP1) is a multifunctional extracellular matrix molecule that belongs to a family of homologous glycoproteins. TSP1 can be produced by many cell types that are involved in wound repair, including keratinocytes, fibroblasts, endothelial cells, and macrophages. To investigate the kinetics of TSP1 synthesis in wounds, mRNA from murine full thickness excisional dermal wounds was analyzed. TSP1 mRNA was undetectable in normal skin but was present in early wounds. After day 1, TSP1 mRNA levels within wounds slowly decreased, returning to undectable day 10. In situ hybridization revealed that the primary source of the TSP1 mRNA within wounds was macrophage-like cells in the inflammatory infiltrate. To explore the function of TSP1 production in sites of injury, wounds were treated with antisense TSP1 oligomers. Antisense-treated wounds contained 55 to 66% less TSP1-positive macrophages than control and exhibited a marked delay in repair. This delay included a decreased rate of re-epithelialization as well as a delay in dermal reorganization. The results suggest that TSP1 production by macrophages facilitates the repair process and provide evidence that TSP1 production is an important component of optimal wound healing.

Transrectal ultrasound of the prostate bed after collagen injection.

OBJECTIVE: Transurethral injection of collagen (TCI) may be used to treat urinary incontinence following radical prostatectomy for prostate cancer. The transrectal ultrasound (TRUS) findings after TCI are described in this report. MATERIALS AND METHODS: TRUS exams of four postprostatectomy patients who had undergone TCI were reviewed. Findings were correlated with pathologic specimens obtained at TRUS-guided core biopsy. These histologic specimens were compared with others from postprostatectomy patients who had not undergone TCI. RESULTS: Well defined bladder apex masses of uniform echogenicity, hypoechoic to adjacent fat and muscle, were identified sonographically in all TCI patients. Masses from which positive biopsies were obtained were similar in appearance to those with no malignancy. Hypocellular fibrous tissue and foci of acellular loose connective tissue were identified in the biopsies of those patients who had undergone TCI. No acellular areas were identified in specimens from patients who had not had TCI. CONCLUSION: Sequelae of TCI should be included in the differential diagnosis of perianastomotic masses in postprostatectomy patients. However, the need for biopsy is not obviated as residual or recurrent prostate carcinoma may coexist.

Mechanisms of neutropenia involving myeloid maturation arrest in burn sepsis.

OBJECTIVE: To determine the mechanisms that lead to the decrease in bone marrow production of neutrophils during burn sepsis. SUMMARY BACKGROUND DATA: Impaired bone marrow granulopoiesis during burn sepsis often results in neutropenia despite elevated circulating levels of granulocyte colony-stimulating factor (G-CSF). To date, neither the specific stages of neutrophil maturation involved in the bone marrow suppression nor the mechanisms for the impairment have been determined. METHODS: Peripheral blood absolute neutrophil count and G-CSF levels were determined in mice 3 days after randomization to control, burn alone, or burn plus a topical inoculation of Pseudomonas aeruginosa (1000 colony-forming units). Bone marrow aspirates were analyzed for their neutrophil differentiation patterns by Gr-1 antigen expression and their G-CSF receptor status. Histologic analysis of liver, lung, spleen, and wound site was performed. RESULTS: In burn sepsis, absolute neutrophil count was reduced whereas plasma G-CSF levels were elevated, and myeloid differentiation was significantly shifted toward the immature mitotic myeloid cells. Bone marrow G-CSF receptor mRNA levels and G-CSF-stimulated proliferation were substantially decreased in burn sepsis. Histologic analysis revealed no significant neutrophil infiltration into the tissues. CONCLUSIONS: In thermal injury with superimposed sepsis, neutropenia and myeloid maturation arrest, despite the elevated levels of G-CSF, correlate with the reduction in bone marrow G-CSF receptor expression. These observations may provide a potential mechanism for neutropenia in sepsis.

BCL-2 but not its Epstein-Barr virus-encoded homologue, BHRF1, is commonly expressed in posttransplantation lymphoproliferative disorders.

Posttransplantation lymphoproliferative disease (PTLD) is virtually always associated with Epstein-Barr virus (EBV) infection. BCL-2 and other proteins that confer resistance to apoptosis have been implicated in the pathogenesis of a variety of malignancies including lymphomas. One EBV protein, BHRF1, is a homologue of BCL-2, whereas another, the latency membrane protein 1 (LMP-1), upregulates BCL-2 expression in vitro. In the present study, we used immunohistochemistry to study the expression of these viral and cellular proteins as well as a variety of other EBV-encoded proteins in PTLD. BHRF1 was not detected in any PTLD specimen, whereas BCL-2 was shown in 12 of 17 lesions examined. With one exception, all LMP1-positive cases also expressed BCL-2 and the absence of LMP1 was always associated with a lack of BCL-2 expression. The results do not support a role for the EBV homologue of BCL-2 in PTLD, but they do support a role for viral induction of BCL-2 expression.

Directed and random biopsies of the prostate: indications based on combined results of transrectal sonography and prostate-specific antigen density determinations.

OBJECTIVE: We studied the usefulness of transrectal sonography, prostate-specific antigen levels, and prostate-specific antigen density as indications for directed and random biopsies of the prostate in patients with possible prostatic cancer. MATERIALS AND METHODS: A total of 141 patients with increased levels of prostate-specific antigen or abnormal findings on digital rectal examination had transrectal sonography of the prostate and determination of prostate-specific antigen density. Through sonographic visualization, all patients had biopsies of possible cancerous lesions and random biopsies of regions of the prostate that appeared normal. Histologic results were correlated with sonographic findings and determinations of prostate-specific antigen levels and prostate-specific antigen density. RESULTS: Adenocarcinoma was detected in 40 (28%) of the 141 patients. Transrectal sonography showed an abnormality that was determined by directed biopsy to be a carcinoma in 27 (68%) of the 40 patients. Transrectal sonography showed no carcinoma in 13 patients (32%) for whom random biopsy revealed a tumor. The sensitivity of sonography was 68%, and the specificity was 49%. The combination of sonographic findings suggestive of cancer and increased prostate-specific antigen density had a sensitivity of 75% and a specificity of 75%; we calculated a sensitivity of 72% and a specificity of 56% for the combination of sonographic findings suggestive of tumor and increased levels of prostate-specific antigen. Thirty-nine (97%) of 40 patients with cancer had either sonographic findings suggestive of tumor or increased prostate-specific antigen density, and one (3%) had no evidence of tumor on sonography and a normal prostate-specific antigen density. CONCLUSION: Directed and random sonographic biopsies of the prostate are indicated in patients with sonographic findings suggestive of tumor and increased prostate-specific antigen density and in patients with abnormal sonographic findings and normal prostate-specific antigen density. Random biopsies are indicated in patients with normal sonographic findings and increased prostate-specific antigen density. In our series, random biopsies were not indicated in 25 of 26 patients with normal sonographic findings and normal prostate-specific antigen density. Further research on the need for random biopsies when there are no sonographic abnormalities and when prostate-specific antigen densities are not elevated is warranted.

Telomerase activity, telomere length, and DNA ploidy in prostatic intraepithelial neoplasia (PIN).

PURPOSE: To investigate the relationship of telomerase activity, telomere length, and DNA ploidy in high grade prostatic intraepithelial neoplasia (PIN). MATERIALS AND METHODS: Tissue samples were carefully microdissected to obtain adenocarcinoma or PIN-containing tissue free of cancer. Telomerase activity was measured using the PCR-based telomeric repeat amplification protocol (TRAP). Telomere length was estimated from Southern blots of telomere restriction fragments (TRFs). DNA ploidy of PIN and carcinoma was determined by image analysis of adjacent Feulgen stained tissue sections. RESULTS: Telomerase activity was found in 4 of 25 samples (16%) of high grade PIN. All telomerase positive PIN foci had a diploid DNA content. Although 5 of 25 samples (25%) of high grade PIN foci analyzed were DNA aneuploid, none of these demonstrated telomerase activity. Telomerase positive foci of prostate carcinoma (69% of all cancer foci analyzed) displayed heterogeneity in TRF length, with a mean TRF length two kilobase pairs shorter than that of telomerase negative specimens. CONCLUSIONS: Telomerase activity is present in a low percentage of high-grade PIN foci, which are diploid by DNA content measurements.