CD44s expression in human colon carcinomas influences growth of liver metastases

CD44 is a family of cell-surface adhesion molecules which exist in several isoforms arising from mRNA alternative. Malignant transformation of colonic mucosa is associated with alterations in CD44 expression, which result in up-regulation of high-molecular-weight CD44 isoforms and down-regulation of CD44s. We have demonstrated that stable transfection of CD44s into colon-carcinoma cell lines reduces their tumorigenicity. To understand the influence of CD44s expression on the metastatic potential of human colon carcinomas, we measured the ability of several different CD44s-transfected colon carcinomas to establish experimental liver metastases following splenic inoculation in mice. We observed that introduction of CD44s into 2 different human colon carcinoma cell lines, HT29 and KM12C6, resulted in reduced growth of liver metastases by as much as 75%. To explore the relationship between hyaluronate adhesion and metastasis, we transfected HT29 cells with cDNA encoding a mutant CD44s that does not bind to hyaluronate. HT29 transfectants expressing this mutant CD44s demonstrate an 84% reduction in growth of liver metastases, despite minimal binding to hyaluronate by the mutant CD44s. In concert, these results indicate that CD44s down-regulation, which occurs with malignant transformation of colonic mucosa, is associated with enhanced growth of experimental liver metastases. Consequently, the functional consequences of CD44s down-regulation in colon carcinomas may be just as significant as the consequences of up-regulation of other CD44 isoforms.

Mouse endostatin inhibits the formation of lung and liver metastases

Angiogenesis is required for tumor formation. Several studies have demonstrated that tumor angiogenesis is regulated by a balance between proangiogenesis and antiangiogenesis factors and that this balance varies in different organ environments. To investigate whether expression of an angiogenesis inhibitor by cancer cells could alter this balance and prevent tumor formation in different organ environments, we engineered stable transfectants from RenCa mouse renal carcinoma cells and SW620 human colon carcinoma cells to constitutively secrete a mouse endostatin protein with c-myc and polyhistidine (His) tags. Production and secretion of the endostatin-c-myc-His fusion protein by endostatin-transfected cells were confirmed by immunofluorescence staining and Western blot analysis. The endostatin transfectants and control transfectants, stably transfected with a control plasmid, had similar in vitro growth rates compared with their parental cell lines. Conditioned medium from endostatin-transfected cells inhibited human umbilical vein endothelial cell proliferation by 36-51% compared with conditioned medium from control cells. After inoculation into mice, flank tumors from endostatin-transfected cells were 73-91% smaller than flank tumors from control cells after 3 weeks. Inoculation of a cell mixture containing 25% endostatin-transfected cells and 75% control cells resulted in inhibition of flank tumor formation as effective as after inoculation of 100% endostatin-transfected cells. Formation of lung metastases by RenCa endostatin-transfected cells and formation of liver metastases by SW620 endostatin-transfected cells were dramatically inhibited compared with formation of metastases by control cells. These findings demonstrate that endostatin can inhibit tumor formation in different organ environments and that gene delivery of endostatin into even a minority of tumor cells may be an effective strategy to prevent progression of micrometastases to macroscopic disease.

[Development and characterization of a monoclonal antibody which recognizes a new prostate-organ specific antigen]

PURPOSE

Development and characterization of monoclonal antibodies which recognizes a new prostate-organ specific antigen.

METHOD

For development of monoclonal antibodies, hybrid cells were prepared by fusion of spleen cells of BALB/c mice immunized with the homogenates of surgically resected prostatic tissue and P 3 x Ag 8 U 1 (P 3 U 1) murine myeloma cells. Supernatants of hybrid clones were primarily screened using an ELISA on human prostatic cancer cell line PC-3 and human bladder cancer cell line T-24. In the secondary screening, they were tested on normal tissues by immunohistochemical staining. To characterize the antigens, biochemical analyses were performed using seminal plasma as an antigen by western blotting and gel filtration, and the reactivity of antibodies were compared with that of antibodies against prostatic acid phosphatase (PAP), prostate-specific antigen (PSA) and gamma-seminoprotein (gamma-Sm).

RESULTS

A monoclonal antibody termed KP-9 was obtained and it only reacted with PC-3 and prostate tissues, but did not react with other cell lines and normal tissues. Immunohistochemical staining of prostate tissue revealed that KP-9 stained grandular epithelium and grandular exudate of normal and malignant prostatic tissues, and especially, strongly stained the apical site of grandular epithelium. Western blotting and gel filtration of seminal plasma suggested that the molecular weight of the KP-9 antigen was more than 300,000 and was different from PAP, PSA and gamma-Sm.

CONCLUSION

We have developed a monoclonal antibody, KP-9 which specifically reacts with prostatic cancer as well as benign prostatic tissues. The antigen recognized by KP-9 appeared to be a new prostate-organ specific antigen and may be a useful marker for prostatic cancer such as PAP, PSA and gamma-Sm.

Type I interferons (IFNs) regulate tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) expression on human T cells: A novel mechanism for the antitumor effects of type I IFNs

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a proapoptotic member of the TNF family of type II membrane proteins, which constitutes one component of T cell cytotoxicity. In this study, we investigated the expression and function of TRAIL in human peripheral blood T (PBT) cells. Although freshly isolated PBT cells did not express a detectable level of TRAIL on their surface, a remarkable TRAIL expression was rapidly induced on the surface of both CD4(+) and CD8(+) PBT cells upon stimulation with anti-CD3 monoclonal antibody and type I interferons (IFNs). This enhancement of TRAIL expression was a unique feature of type I IFNs (IFN-alpha and IFN-beta), and neither type II IFN (IFN-gamma) nor various other cytokines enhanced TRAIL expression on anti-CD3-stimulated PBT cells. Type I IFNs have been used for clinical treatment of renal cell carcinomas (RCCs), and we found that most RCC cell lines were susceptible to TRAIL-induced apoptosis. Type I IFNs substantially augmented cytotoxic activity of anti-CD3-stimulated PBT cells against RCC cell lines in a TRAIL-dependent manner. These results indicate a unique feature of type I IFNs to regulate TRAIL-mediated T cell cytotoxicity, which may be involved in the antitumor effects of type I IFNs against various tumors.

Involvement of CD44 in matrix metalloproteinase-2 regulation in human melanoma cells

CD44 is a family of cell-surface-adhesion proteins that are thought to play an important role in cancer invasion and metastasis. However, the specific mechanisms by which CD44 expression modulates invasion or metastasis are not well understood. In the current study, we have demonstrated that treatment of human melanoma cells with a CD44 MAb, F10-44-2, induces up-regulation of matrix metalloproteinase-2 (MMP-2) protein and mRNA. Moreover, treatment of melanoma cells with MAb F10-44-2 enhances their migration through gelatin-coated membranes and invasion through reconstituted basement membranes. Treatment of melanoma cells with several known CD44 ligands, including hyaluronate, extracellular-matrix proteins, and osteopontin, did not induce MMP-2 production. CD44 binding by F10-44-2 MAb results in induction of MMP-2 expression, which is associated with enhanced cell migration and invasion. These findings have several implications for investigations into tumor metastasis, development, and lymphocyte function.

Multifocal renal cell carcinoma in Japanese patients with tumors with maximal diameters of 50 mm. or less

PURPOSE

We determined the risk of local recurrence in 64 Japanese patients a median of 69 years old with renal cell carcinoma who were possible candidates for nephron sparing surgery and who underwent radical nephrectomy.

MATERIALS AND METHODS

A total of 64 kidneys in which tumors 50 mm. or less were resected were prospectively examined pathologically in 3 mm. sections. The incidence of satellite tumors and the relationship between the pathological findings of the primary and satellite tumors were evaluated.

RESULTS

Satellite tumors were identified in 10 of the 64 kidneys (15.6%), a rate similar to that reported in the United States. The correlation of histological findings between primary and satellite tumors was 70% for tumor grade. Satellite tumor grade was less than that of the primary lesion in 3 cases. In 60% of the specimens with multifocal renal cancer satellite tumors were within 10 mm. of the margin of the primary tumor. At this distance, if partial nephrectomy had been performed, the satellite lesions would have been missed in 4 of these 10 patients (40%). Of the 10 kidneys with satellite renal tumors 8 (80%) had vascular invasion of the primary tumor. Multiple logistic regression analysis demonstrated that vascular invasion was a significant predictor of multifocality of renal cell carcinoma.

CONCLUSIONS

Our results suggest that vascular invasion is a risk factor for multifocality in Japanese patients with renal cell carcinoma. Therefore, careful and long-term followup is necessary in patients with renal cell carcinoma who have undergone nephron sparing surgery, especially those with vascular invasion of the primary tumor.

Recurrent annular erythema in a case of seronegative Sjögren's syndrome

We describe a case of Sjögren's syndrome who repeatedly developed annular erythema on her extremities. Her anti-nuclear antibody, anti-SSA/Ro antibody, and anti-SSB/La antibody were all negative. Characteristics of the annular erythema included a tendency to appear on the extremities especially in summer, spontaneous regression after 1-2 weeks, and residual slight pigmentation. The histological findings revealed dermal perivascular lymphocytic infiltration admixed with some neutrophils. Slight exsudative changes were found in the upper dermis. There were no epidermal changes. This case suggests the existence of annular erythema which may not be related to the anti-SSA/Ro or anti-SSB/La antibody. Unknown factors other than those antibodies may be involved in the pathogenesis of the annular erythema.

Overexpression of Bcl-2 in bladder cancer cells inhibits apoptosis induced by cisplatin and adenoviral-mediated p53 gene transfer

To investigate the effects of the expression of Bcl-2 protein in bladder cancer on the apoptosis induced by cisplatin or adenoviral-mediated p53 gene (Ad5CMV-p53) transfer, we transfected the bcl-2 gene into KoTCC-1, a human bladder cancer cell line that does not express the Bcl-2 protein. The Bcl-2-transfected KoTCC-1 (KoTCC-1/B) exhibited significantly higher resistance to both cisplatin and Ad5CMV-p53 transfer than did either the parental KoTCC-1 (KoTCC-1/P) or the vector-only transfected cell line (KoTCC-1/C). The flow cytometric analysis of the propidium iodide-stained nuclei and DNA fragmentation analysis after cisplatin or Ad5CMV-p53 treatment revealed DNA degradation in both KoTCC-1/P and KoTCC-1/C, whereas KoTCC1/B showed a marked inhibition of DNA degradation. Following the treatment with cisplatin or Ad5CMV-p53, the accumulation of p53 protein was highly detectable for a long period in KoTCC-1/B compared to that in KoTTC-1/P and KoTCC-1/C. Furthermore, the cisplatin and Ad5CMV-p53 treatments each reduced the volume of the subcutaneous tumors established in nude mice formed by KoTCC-1/P or KoTCC-1/C; in contrast, their reductive effects on the tumors formed by KoTCC-1/B were significantly suppressed. The intraperitoneal tumor cell implantation model revealed that the prognoses of mice injected with KoTCC-1/B were significantly inferior to those of the mice injected with either KoTCC-1/P or KoTCC-1/C after treatment with cisplatin or Ad5CMV-p53. These findings suggest that the expression of Bcl-2 in bladder cancer cells interferes with the therapeutic effects of cisplatin and Ad5CMV-p53 through the inhibition of the apoptotic pathway.

Basic fibroblast growth factor regulates matrix metalloproteinases production and in vitro invasiveness in human bladder cancer cell lines

PURPOSE

This study was designed to investigate the effect of endogenous basic fibroblast growth factor (FGF-2) on matrix metalloproteinases (MMPs) production and in vitro invasive potential of human bladder cancer cell lines.

MATERIALS AND METHODS

The human bladder cancer cell lines, HT1376 and KoTCC-1, were used in this study. The mRNA for FGF receptor has been shown to be expressed in both cell lines; the mRNA for FGF-2 is expressed in only KoTCC-1. The effects of FGF-2 expression on HT1376 by gene transfection and those of FGF-2 antisense oligonucleotides treatment on KoTCC-1 were analyzed by zymography and in vitro tumor cell invasion assay.

RESULTS

The introduction of human FGF-2 gene into HT1376 cells markedly enhanced both the MMP-2 and MMP-9 production, and the in vitro invasive potential was also increased. In contrast, the exposure of KoTCC-1 cells to FGF-2 specific antisense oligonucleotides decreased the MMP-2 production and in vitro invasive potential, but the exposure to FGF-2 sense oligonucleotides did not.

CONCLUSIONS

These findings suggest that FGF-2 plays an important role in the invasive process of human bladder cancer in part through the regulation of MMPs production.

Percutaneous treatment of transitional cell carcinoma of the upper urinary tract

BACKGROUND

We evaluated the long-term effect of percutaneous resection in 2 Japanese patients with transitional cell carcinoma of the renal pelvis, and reviewed the medical literature on similar patients, to determine the appropriate indications for percutaneous treatment of transitional cell carcinoma in the upper urinary tract.

RESULTS

Indications for endoscopic resection in the 2 patients were renal insufficiency and unsuitability for major open surgery. The patients had no recurrence during follow-up. Seven previous reports described percutaneous resection of upper urinary tract transitional cell carcinoma in 82 patients. Although 72.6% of the patients were successfully treated by percutaneous resection, half of the patients with grade 3 carcinoma developed recurrence.

CONCLUSION

These results, together with those of the 7 published reports, suggest that percutaneous resection should be limited to selected patients with low-grade transitional cell carcinoma.

Giant cell pneumonia: light microscopy, immunohistochemical, and ultrastructural study of an autopsy case

An autopsy case of measles giant cell pneumonia with intranuclear inclusion bodies is reported. This case of giant cell pneumonia was studied by light microscopy and immunohistochemistry using monoclonal and polyclonal antibody to measles and by electron microscopy (EM). Light microscopic examination showed multinucleated epithelial giant cells with intranuclear and intracytoplasmic inclusions. The giant cells contained prominent, sharply marginated, eosinophilic intranuclear inclusions typical of classic measles pneumonia. Presence of measles antigen was confirmed using both monoclonal and polyclonal antibodies by peroxidase antiperoxidase method. Monoclonal antibody stained positively for intracytoplasmic and intranuclear inclusions. Electron microscopic examination of lung tissue showed intranuclear inclusions of filamentous or worm like nucleocapsid materials in multinucleated epithelial giant cells. The results suggest that this is a case of measles giant cell pneumonia and the intranuclear inclusion bodies are measles viral particles.

Comparison of hormonal therapy and chemohormonal therapy in patients with newly diagnosed clinical stage D prostatic cancer

BACKGROUND

In order to examine the usefulness of chemohormonal therapy, we conducted a multicentered randomized trial comparing hormonal therapy, using a luteinizing hormone-releasing hormone (LH-RH) agonist, with chemohormonal therapy, hormonal therapy plus cyclophosphamide (CPM), in patients with newly diagnosed clinical stage D prostatic cancer.

METHODS

Between January 1991 and March 1995, 41 evaluable patients with stage D prostatic cancer were randomized into 2 groups: group A (hormonal therapy alone), goserelin acetate depot 3.6 mg subcutaneously every 4 weeks: group B (chemohormonal therapy), goserelin acetate depot 3.6 mg subcutaneously and CPM 1000 mg/m2 intravenously every 4 weeks. The responses to the therapies were evaluated based on the criteria of The Japanese Urological Association.

RESULTS

There were no significant differences between the 2 groups with regard to objective and subjective response rates. No advantage in chemohormonal therapy was observed in the survival rate and progression-free survival rate. However, the survival rate and progression-free survival rate of responders were significantly higher than those of nonresponders in both groups. When the results were categorized by histologic grade patients with poorly-differentiated adenocarcinoma had significantly higher response rates, survival rates, and disease-progression-free survival rates in Group B compared to similar patients in Group A.

CONCLUSIONS

We conclude that chemohormonal therapy does not definitely improve the clinical response and prognosis of patients with stage D prostatic cancer; however, for patients with poorly-differentiated adenocarcinoma, chemohormonal therapy is a useful treatment.

[Radical prostatectomy for localized prostate cancer]

We studied 81 patients who underwent radical prostatectomy for prostate cancer. Ten, 57 and 14 patients were clinically diagnosed with stage T1, T2 and T3, respectively. Pelvic lymph node dissection was performed prior to prostatectomy in all cases. The neurovascular bundle was preserved in 21 patients. Compared with pathological stage, the accuracy rate of clinical staging in T1, T2 and T3 was 40, 46 and 64% respectively. Approximately half of the patients clinically diagnosed with stage T2 were pT3. The positive rate of lymph node in pT2 and pT3 was 3.3 and 37% respectively, showing a marked difference between these two pathological stages. The 3-year non-recurrence rates were 89% in patients with pT2 and 79% in pT3. In the well differentiated carcinoma group, no patients had recurrence for up to 3 years. All of the patients with infiltration (INF) gamma showed recurrence within 3 years. Fifty-five patients had no problem on urination post-operatively, while the other 23 patients had a mild or moderate incontinence and the remaining 3 patients had a small urine stream. Regarding erectile potency, 4 out of 18 evaluable patients were potent.

Short report: herpes-like DNA sequences in African-endemic and acquired immunodeficiency syndrome-associated Kaposi's sarcoma

Recently, the unique nucleic acid closely related to the herpes-like sequences has been found in acquired immunodeficiency syndrome (AIDS)-associated Kaposi's sarcoma (KS). We have confirmed the presence of herpes-like DNA sequences in six cases of AIDS-associated KS and three of the nine cases of African-endemic KS in adults, but not in eight cases of KS in children from the same area. These sequences were seen in a histologically early stage of KS. Our results suggest that herpes-like DNA sequences may play an important role in the pathogenesis of AIDS-associated KS.

NF-kappa B is induced in the nuclei of cultured rat aortic smooth muscle cells by stimulation of various growth factors

We investigated whether induction of transcription factor NF-kappa B is involved in the proliferation of cultured rat aortic smooth muscle cell using electrophoretic mobility shift assay and immunocytochemistry. NF-kappa B was induced in the nucleus in a dose-dependent manner when the smooth muscle cells were stimulated by various growth factors such as PDGF-BB, bFGF, EGF and IGF-1, but not growth inhibitors such as TGF-beta and IFN-gamma. Among growth factors, PDGF-BB and bFGF, more potent growth stimulators, induced higher kappa B binding activity than EGF or IGF-1. These evidences were also supported by the results obtained with immunocytochemistry. Immunocytochemistry also showed that the induced NF-kappa B contained p50 and p65. These results suggest that NF-kappa B induction may be involved in the proliferation of vascular smooth muscle cell.

Rejection of mouse renal cell carcinoma elicited by local secretion of interleukin-2

We introduced the interleukin-2 (IL-2) gene into mouse renal cell carcinoma (RenCa) in order to examine the mechanism of tumor rejection. IL-2 gene-transfected RenCa (RenCa/IL-2Hi) exhibited marked retardation of tumor growth when implanted in a syngeneic host. Growth retardation of RenCa/IL-2Hi was also observed in athymic nude mice even after depletion of natural killer (NK) cells by treatment with anti-asialo GM1 antibody. Histological analysis of RenCa/IL-2Hi tumors disclosed non-specific inflammatory changes in syngeneic hosts. Co-injection of Bacillus Calmette Guerin with RenCa/IL-2Hi considerably enhanced the anti-tumor effects. Taken together, these findings strongly suggest that in situ IL-2 production leads to tumor rejection through non-specific inflammatory responses without participation of T cells and NK cells. On the other hand, the syngeneic mice that had rejected RenCa/IL-2Hi acquired immunity against parental RenCa, suggesting possible participation of memory T cells in the second rejection of the tumor.

[In vitro direct antiproliferative activity and in vivo antitumor activity of bropirimine against bladder cancer]

Bropirimine is an antitumor agent currently used in clinical trials on bladder cancer. It is known to induce IFN, to activate NK cells and to inhibit the growth of tumor cells. In this study, we examined the in vitro and in vivo efficacy of bropirimine on human and murine bladder cancer. Bropirimine showed in vitro antiproliferative activity on the human bladder cancer cell lines, T 24 and KoTCC-1. This activity was not: affected by the neutralizing antibodies against IFN-alpha, TNF-alpha or IL-1 beta, indicating it is the direct activity of bropirimine without involvement of cytokine production by tumor cells. Bropirimine was active at the concentrations comparable to those in serum or urine attained in clinical trials, which suggests that this direct antiproliferative activity is one of the important antitumor mechanisms of bropirimine. In in vivo experiments, bropirimine reduced the growth of transplanted murine MBT-2 and human KoTCC-1 bladder cancers by oral administration every 4 days starting on day 1, but did not show efficacy when the drug treatment was started on day 8. The antitumor activity of bropirimine was dependent on the timing for drug treatment initiation.

Introduction of basic fibroblast growth factor gene into mouse renal cell carcinoma cell line enhances its metastatic potential

To clarify the role of basic fibroblast growth factor (FGF-2) in the malignant progression of renal cell carcinoma, we transfected the FGF-2 gene, which lacks the typical signal sequence, into RenCa, a mouse renal cell carcinoma cell line that does not express FGF-2 mRNA. In an in vitro tumor cell invasion assay, the FGF-2-transfected cell lines (RenCa/F) exhibited 3- to 4-fold higher invasive potential than either the parental RenCa (RenCa/P) or the vector-only transfected cell line (RenCa/C). Zymography showed a marked increase in matrix metalloproteinase 2 (MMP-2) production in the culture supernatants of RenCa/F. Furthermore, when injected i.v. or into the renal subcapsule in syngeneic mice, RenCa/F formed more than 10 times as many metastatic nodules in the lung as did RenCa/P and RenCa/C. Metastases to the liver and mesenteric lymph nodes were observed only after the injection of RenCa/F into the renal subcapsule. In contrast, there was no significant difference in either cell proliferation in vitro or tumor growth in vivo among RenCa sublines. These results suggest that if it is overexpressed, endogenous native FGF-2 plays an important role in the invasion and metastasis of renal cell carcinoma, probably through the production of MMP-2.

Messenger ribonucleic acids for fibroblast growth factors and their receptor in bladder and renal cell carcinoma cell lines

FGF-like growth factors have been detected in the urine of patients with bladder or renal cell carcinoma. FGF-1-like and FGF-2-like proteins have been detected in the urine of patients with bladder carcinoma. However, the expression of FGFs and their receptor in bladder and renal cell carcinoma cells remains limited. We measured the mRNA levels of FGFs and their receptor in these carcinoma cell lines by means of RT-PCR. We detected FGF-8 mRNA expression in murine cell lines of bladder and renal cell carcinomas but not in those of the normal bladder and kidney. Furthermore, FGF-8 mRNA expression was detected in all human bladder and renal cell carcinoma cell lines tested. We also frequently detected FGF-1, FGF-2 and FGF-5 mRNA expression in human bladder and renal cell carcinoma cell lines. These results indicate that FGF-8 is also candidate for marker of these types of carcinoma as well as FGF-1 and FGF-2.

Efficacy of combination antiplatelet therapy and nicardipine for chronic cerebral infarction

To prevent recurrence of cerebral infarction (CI), the efficacy of antiplatelet therapy, when used in combination with a calcium antagonist, was examined. The study subjects were 57 chronic CI patients (40 men, 17 women; mean age, 68.5 years) who experienced either CI or its recurrence more than 3 months before the start of the study. They were randomly allocated into one of the following four groups for the 8-week study; group A--ticlopidine hydrochloride 200 mg once daily and nicardipine hydrochloride 20 mg three times daily (TID); group B--ticlopidine hydrochloride 200 mg once daily; group C--aspirin 81 mg once daily and nicardipine hydrochloride 20 mg TID; or group D--aspirin 81 mg once daily. Platelet aggregation was measured before treatment and 4 and 8 weeks after the initiation of each therapy by using adenosine diphosphate (ADP) (2 microM and 0.5 microM) and collagen (2 micrograms/mL), and evaluated in terms of percent maximum platelet aggregation. Results showed significant suppression of 2.0 microM ADP platelet aggregation in groups A, B, and C. At 0.5-microM ADP, only groups A and B showed significant platelet aggregation suppression. All groups showed significant suppression of collagen platelet aggregation. In comparing single therapy with combination therapy, groups A and B were not significantly different from one another after 4 or 8 weeks in 2-microM ADP or collagen platelet aggregation suppression. In contrast, group C had significantly greater suppression of both 2-microM ADP and collagen aggregations compared with group D. In conclusion, nicardipine hydrochloride administration with aspirin may be a useful alternative therapy for the prevention of CI recurrence.

The pattern of pediatric solid malignant tumors in western Kenya, east Africa, 1979-1994: an analysis based on histopathologic study

This study analyzed histopathologic specimens of 600 pediatric solid malignant tumors seen during the period 1979-1994 at the histopathology laboratories of the Rift Valley Provincial General Hospital in Nakuru, the Nyanza Provincial General Hospital in Kisumu, and the Uasin Gishu Hospital in Eldoret in western Kenya. The crude incidence rate of each malignancy per 100,000 children per year was calculated. The patterns of malignancies were examined with a focus on tumor incidence, age, sex, geographic, and ethnic distribution to relate the tumors to putative environmental and genetic causative factors. The six common tumors were Burkitt's lymphoma (33.5%), non-Hodgkin's lymphoma (21.8%), retinoblastoma (11.5%), Kaposi's sarcoma (6.1%), nephroblastoma (4.5%), and Hodgkin's disease (4.1%). Significantly high crude incidence rates for lymphomas and Kaposi's sarcoma showed a characteristic ethnogeographic distribution. The majority of the tumors were found concentrated around Lake Victoria and showed decreasing occurrence as one moved towards the semi-arid and highland areas. We concluded that environmental factors seem to play a major role in childhood tumors in western Kenya.

[Ectopic production of HCG beta by bladder carcinoma in vitro and in vivo]

BACKGROUND

Ectopic production of immunoreactive hCG/hCG beta (IR-hCG beta) by bladder tansitional cell carcinoma cell lines was investigated in vitro and in vivo.

METHODS

As an in vitro study, IR-hCG beta in culture media from 2 bladder transitional cell carcinoma cell lines (KoTCC-1 and HT-1197) was analyzed by three kinds of enzyme immunoassays (EIA) which were specific for intact hCG, free hCG beta and beta-core fragment (beta-CF). As an in vivo study, distribution of IR-hCG beta was analyzed in tumor tissues, sera, and urine of the nude mice and the nude rat transplanted with KoTCC-1 cell line.

RESULTS

Both of the cell lines were determined to secrete IR-hCG beta into the media, which consisted principally of free hCG beta. Intact hCG and beta-CF were scarecely detected in the media. Immunohistochemical study revealed the localization of IR-hCG beta in transitional cell carcinoma cells of the transplanted tumor. Although a large amount of IR-hCG beta could be detected in both of the serum and urine from the animals, there were quantitative and qualitative differences between serum and urinary IR-hCG beta. Quantitatively, the concentrations of IR-hCG beta in the urine were consistently much higher than those in the serum. Qualitatively, free hCG beta was exclusively detected in the serum whereas a large amount of beta-CF, in addition to free hCG beta, were found in the urine. Intact hCG could not be detected in both serum and urine. These distributions of IR-hCG beta in the animals bearing tumors were completely analogous to those in patients with bladder carcinoma.

CONCLUSION

The present results suggested that ectopic production of IR-hCG beta by bladder carcinoma is not rare phenomenon and it is clinically useful as a tumor marker when beta-CF is measured in the urine.