Disialosyl galactosylgloboside as an adhesion molecule expressed on renal cell carcinoma and its relationship to metastatic potential.

Aberrant glycosylation expressed in specific types of human cancer may define stage, direction, and fate of tumor progression. Well-studied examples are expression of sialosyl-Lewis(x) or sialosyl-Lewis(a) in colorectal carcinoma and histo-blood group A and H/Le(y) in lung cancer. In renal cell carcinoma (RCC), expression of sialosyl-Lewis(x) has no correlation with metastatic potential. Clinicopathological studies have revealed that the degree of expression of disialosyl galactosylgloboside (DSGG) and monosialosyl galactosylgloboside is correlated with metastatic potential (to lung and lymph nodes) of RCC and inversely correlated with patient survival. In the present study, we compared the adhesion of RCC lines to sections of various tissues measured by Stamper-Woodruff assay and other similar assays under dynamic flow conditions. Of the eight RCC lines tested, only TOS-1 (which expresses DSGG) bound strongly to lung tissue sections. TOS-1 did not bind to sections of liver, kidney, or lymph nodes. In the same eight RCC lines, we also compared expression of DSGG and monosialosyl galactosylgloboside (reflected by reactivity with RM1 and RM2), overall ganglioside patterns, and correlation with lung tissue-binding ability. Under both static and dynamic flow conditions, the binding of TOS-1 cells to lung alveolar tissue was correlated with their DSGG expression, i.e., the binding was inhibited by RM2 but not by RM1. This binding was also inhibited by sialidase but not by EDTA (i.e., it was CA 2+ independent). The other seven cell lines (TOS-2, TOS-M, SMKT-R1, -R2, -R3, and -R4, and ACHN), which do not express DSGG, showed much weaker adhesion to lung tissue. None of the eight cell lines showed E- or P-selectin-dependent adhesion. These results suggest the existence of a yet-uncharacterized sialoadhesive receptor++ that specifically recognizes DSGG. This receptor could be the binding target in RCC metastasis to lung.

Cancer-associated expression of glycolipid sulfotransferase gene in human renal cell carcinoma cells.

Human renal cell carcinoma (RCC) tissue and a cell line derived therefrom, SMKT-R3, showed markedly increased glycolipid sulfotransferase [cerebroside sulfotransferase (CST); EC 2.8.2.11] activity and accumulated sulfoglycolipids. Recently, we cloned a human CST cDNA from a SMKT-R3 cDNA library (K. Honke et al., J. Biol. Chem., 272: 4864-4868, 1997). In this study, we investigated the expression of the CST gene in seven human RCC lines (SMKT-R1, SMKT-R2, SMKT-R3, SMKT-R4, TOS-1, TOS-2, and ACHN) and their normal counterpart, human renal proximal tubular cells. On Northern blot analysis, a marked increase of CST mRNA was observed in every RCC line, except for ACHN, as compared with normal cells. ACHN cells showed a slightly increased level of CST mRNA. CST activity was correlated with the amount of mRNA. Sulfoglycolipid analysis revealed that expression of lactosylceramide sulfate was correlated with the CST level. Furthermore, we examined the effects of epidermal growth factor (EGF), tetradecanoylphorbol-13-acetate, and genistein, which are known to regulate CST activity in SMKT-R3 cells, on CST-gene expression in various RCC cells. On treatment with EGF, CST mRNA time-dependently increased in accord with its activity in SMKT-R3 cells. Yet, augmentation by EGF was only observed in SMKT-R3. In contrast, a reduction of CST mRNA and activity by tetradecanoylphorbol-13-acetate and genistein was observed in all of the lines examined. Taken together, these findings indicate that in human RCC cells, the CST gene is generally overexpressed via a signaling pathway involving protein kinase-C and tyrosine kinases.

Microsatellite instability in bladder cancer.

Somatic instability at microsatellite repeats was detected in 6 of 200 transitional cell carcinomas of the bladder. Instabilities were apparent as changes in (GT)n repeat lengths on human chromosome 9 for four tumors and as alterations in a (CAG)n repeat in the androgen receptor gene on the X chromosome for three tumors. Single locus alterations were detected in three tumors, while three other tumors revealed changes in two or more loci. In one tumor we found microsatellite instability in all five loci analyzed on chromosome 9. The alterations detected were either minor 2-base pair changes or larger (> 2 base pairs) alterations in repeat length. All six tumors were low stage (Ta-T1), suggesting that these alterations can occur early in bladder tumorigenesis.

Two molecular pathways to transitional cell carcinoma of the bladder.

Noninvasive transitional cell carcinomas of the bladder can have two distinct morphologies suggesting they contain different genetic alterations. Papillary transitional cell carcinomas (T(a) tumors) are often multifocal and only occasionally progress, whereas flat tumors (carcinomas in situ, CIS), frequently progress to invasive disease. We examined 216 bladder tumors of various stages and histopathologies for two genetic alterations previously described to be of importance in bladder tumorigenesis. Loss of heterozygosity of chromosome 9 was observed in 24 of 70 (34%) T(a) tumors but was present in only 3 of 24 (12%) CIS and dysplasia lesions (P = 0.04). In contrast, only 1 of 36 (3%) T(a) tumors contained a p53 gene mutation compared to 15 of 23 (65%) CIS and dysplasias (P < 0.001), a frequency comparable to that observed in muscle invasive tumors (25 of 49; 51%). The presence of p53 mutations in CIS and dysplasia could explain their propensities to progress since these mutations are known to destabilize the genome. Analysis of several tumor pairs involving a CIS and an invasive cancer provided evidence that the chromosome 9 alteration may in some cases be involved in the progression of CIS to more invasive tumors, in addition to its role in the initiation of T(a) tumors. However, the CIS and secondary tumor were found to contain different genetic alterations in some patients suggesting divergent progression pathways. Bladder carcinogenesis may therefore proceed through two distinct genetic alteration pathways responsible for generating superficial tumors with differing morphologies and pathologies.

Role of chromosome 9 in human bladder cancer.

The tumors of 20 patients with multifocal primary transitional cell carcinoma of the bladder or lymph node metastases were examined for molecular genetic defects which we have previously found to be present in > 50% of invasive tumors. These included loss of heterozygosity (LOH) of chromosome 9, which occurs in superficial as well as invasive bladder tumors, and LOH of chromosome 17p and p53 mutations, which are commonly found only in invasive tumors. Analysis of multiple or recurrent primary tumors in 7 patients for these markers was generally consistent with recently published data that the tumors are monoclonal in origin and that p53 mutations occur as a late event in the generation of invasive bladder cancers. Comparison of the primary tumors and metastases to regional lymph nodes in 14 patients demonstrated a complete concordance between the molecular genetic defects present, showing that LOH of chromosomes 9 and 17p and p53 mutations occurred in the primary tumors before metastasis. Because of the importance of chromosome 9 in bladder cancer, we mapped the location of a putative tumor suppressor gene by restriction fragment length polymorphism analysis of 123 cases obtained in this and earlier studies. Most of the tumors showed LOH for more than one marker on chromosome 9. Results of mapping of 4 tumors with partial deletion of chromosome 9 suggests that the tumor suppressor gene is located between 9p12 and 9q34.1.

Effects of hypercapnia and hypocapnia on [Ca2+]i mobilization in human pulmonary artery endothelial cells.

The hydrogen ion is an important factor in the alteration of vascular tone in pulmonary circulation. Endothelial cells modulate vascular tone by producing vasoactive substances such as prostacyclin (PGI2) through a process depending on intracellular Ca2+ concentration ([Ca2+]i). We studied the influence of CO2-related pH changes on [Ca2+]i and PGI2 production in human pulmonary artery endothelial cells (HPAECs). Hypercapnic acidosis appreciably increased [Ca2+]i from 112 +/- 24 to 157 +/- 38 nmol/l. Intracellular acidification at a normal extracellular pH increased [Ca2+]i comparable to that observed during hypercapnic acidosis. The hypercapnia-induced increase in [Ca2+]i was unchanged by the removal of Ca2+ from the extracellular medium or by the depletion of thapsigargin-sensitive intracellular Ca2+ stores. Hypercapnic acidosis may thus release Ca2+ from pH-sensitive but thapsigargin-insensitive intracellular Ca2+ stores. Hypocapnic alkalosis caused a fivefold increase in [Ca2+]i compared with hypercapnic acidosis. Intracellular alkalinization at a normal extracellular pH did not affect [Ca2+]i. The hypocapnia-evoked increase in [Ca2+]i was decreased from 242 +/- 56 to 50 +/- 32 nmol/l by the removal of extracellular Ca2+. The main mechanism affecting the hypocapnia-dependent [Ca2+]i increase was thought to be the augmented influx of extracellular Ca2+ mediated by extracellular alkalosis. Hypercapnic acidosis caused little change in PGI2 production, but hypocapnic alkalosis increased it markedly. In conclusion, both hypercapnic acidosis and hypocapnic alkalosis increase [Ca2+]i in HPAECs, but the mechanisms and pathophysiological significance of these increases may differ qualitatively.

Squamous cell carcinoma-associated antigen in uroepithelial carcinoma.

We investigated the clinical significance of squamous cell carcinoma (SCC) antigen determined by radioimmunoassay on patients with uroepithelial carcinoma. Serum SCC antigen levels and the positive rates were significantly higher in uroepithelial carcinoma having an SCC component than in normal controls, benign urologic diseases, other urogenital carcinomas, or in pure transitional cell carcinoma (TCC) of uroepithelial carcinomas. A substantial number of patients with pure TCC showed a positive serum level of SCC antigen. Immunohistochemical staining of SCC antigen on the uroepithelial carcinomas confirmed that some, not all, pure TCC, mostly grade 3, expressed SCC antigen in their cells. These results suggested a biologic characteristic of grade 3 TCC which is closely related to that of SCC. The serum levels of SCC antigen correlated well with the disease extensions in uroepithelial carcinoma containing SCC component. Changes in serum levels of SCC antigen following treatment reflected the clinical courses of patients, particularly in those with elevated pretreatment levels. The results of our study indicated that the determination of SCC antigen would be clinically useful for monitoring clinical courses of patients with uroepithelial carcinomas containing SCC component and of those with pure TCC whose pretreatment level was elevated.

Juvenile hemangioma of the testis: analysis of expression of angiogenic factors.

We present a case of juvenile hemangioma of the testis associated with hemangiomas of the liver and skin. The testicular hemangioma appeared to progress after therapy with interferon alpha-2a (IFN alpha-2a), whereas the liver and skin hemangiomas regressed. Analysis of growth factors responsible for proliferation of hemangioma revealed that the tumor expressed vascular endothelial growth factor but not basic fibroblast growth factor (bFGF), which is reported to be inhibited by IFN alpha-2a. This finding suggests that a possible explanation for the inadequate efficacy of IFN alpha-2a for testicular hemangioma is a lack of bFGF expression.

Risk factors for the development of bladder cancer after upper tract urothelial cancer.

OBJECTIVES: To determine the clinical and pathologic risk factors for initial intravesical recurrence in patients with primary renal pelvic and/or ureteral cancer and to examine the progression in the bladder in patients having high risk factors for intravesical recurrence. METHODS: This study included 69 patients with renal pelvic and/or ureteral cancer. We excluded patients with distant metastases, those with a short period of follow-up, and those having a previous history or concomitance of bladder cancer. The exclusion criteria were chosen to avoid contamination by patients with a poor prognosis who might die of the primary cancer before bladder cancer development. Multivariate analysis by Cox's proportional hazards model was used to determine what clinical and pathologic variables significantly affected the initial intravesical recurrence of cancer. We also studied the stage progression of cancer that recurred in the bladder. RESULTS: Initial intravesical recurrence of the cancer was found in 22 patients during a median follow-up period of 53 months (range 12 to 225). The intravesical disease-free rate after upper tract urothelial cancer was 65% (rate of disease recurrence in bladder 35%) at 5 years by the Kaplan-Meier method. The extent (multifocality) of the upper urinary cancer (P = 0.0038) and pathologic stage (P = 0.0409) independently influenced intravesical recurrence. Age, sex, adjuvant chemotherapy, configuration of the primary tumor, primary cancer size, and pathologic grade did not affect recurrence. The rate of stage progression also was not influenced by the extent of the disease in the upper urinary tract. CONCLUSIONS: The extent and pathologic stage of cancer in the upper urinary tract were significant and independent factors for initial intravesical recurrence of cancer. However, no difference was found in clinical outcome in terms of stage progression between patients having high risk factors for intravesical recurrence and those without them.

Limitations of urinary telomerase activity measurement in urothelial cancer.

The reported frequency of detectable telomerase activity in spontaneously voided urine samples from patients with urothelial cancer varied from 0 to 85%. We examined stasis in the bladder and specimen storage as interfering conditions in this assay. Telomerase activity in exfoliated cells was measured by a polymerase-chain-reaction-based assay in spontaneously voided urine from urothelial cancer patients. Effects of retention in the bladder and specimen storage from voiding to measurement of telomerase activity were modeled by suspending 10(6) cells from the cancer-derived T24 line in normal urine (pH 6.5) at 37 degrees C and 25 degrees C, respectively. Hematuria was modeled by adding hemoglobin. In T24 cells suspended in urine at 37 degrees C, telomerase activity had decreased to approximately 20% of preincubation activity after 1 h, and had disappeared after 3 h. In urine at 25 degrees C, telomerase activity in T24 cells had decreased to approximately 40% of preincubation activity at 1 h and to <10% at 6 h. When we examined telomerase activity in exfoliated cells in spontaneously voided urine from urothelial cancer patients (excluding first-voided morning specimens), telomerase activity was detected in only 21% of samples (four of 19) despite measurement with 1 h of voiding and steps to avoid hemoglobin interference. Measurement of telomerase activity in spontaneously voided urine is insufficiently sensitive and reliable for the diagnosis of urothelial cancer.

Non-dehalogenation mechanisms for excretion of radioiodine after administration of labeled antibodies.

In patients or mice with cancer the pharmacokinetic behavior of radioiodinated and radiometal chelated antibodies has been observed to be different. Rapid clearance from the tissues and excretion into the urine can occur after injection of radioiodinated antibodies. These observations have been interpreted to reflect in vivo dehalogenation of the antibody. This publication describes a variety of other mechanisms that can underlie these phenomena. These mechanisms include receptor uptake and catabolism of antibody and instability of the labeled antibody due to the labeling conditions. Specifically, the relative masses of chloramine-T and antibody in the iodination reaction mixture, the level of iodination of the antibody, and the amount of antibody administered to the recipient are all factors which can influence the clearance of radioiodinated antibody from the recipient. The final determinant for the different behavior of radioiodinated and In-111 metal chelated antibody relate to the different biologic pathways of indium when compared to iodine.

131I-Lym-1 in mice implanted with human Burkitt's lymphoma (Raji) tumors: loss of tumor specificity due to radiolysis.

UNLABELLED: Preliminary evaluations of 125I-labeled Lym-1, an anti-lymphoma mouse IgG2a monoclonal antibody, demonstrated favorable tumor uptake in mice bearing human Burkitt's lymphoma (Raji) tumors. In this study, the pharmacokinetics of 125I- and 131I-Lym-1, and the dosimetry, efficacy, and toxicity of 131I-Lym-1 in Raji-tumored mice were evaluated. METHODS: Lym-1 was radioiodinated by the chloramine-T method and analyzed for monomeric fraction and immunoreactivity (antigen cell binding, relative to unmodified Lym-1). Nude mice bearing Raji tumors (20-500 mm3) received 1.5 MBq (40 microCi) 125I-Lym-1, or 1.5, 7.4, 14.8, or 18.5 MBq (40, 200, 400, or 500 microCi) 131I-Lym-1. Pharmacokinetic data (total body and blood clearance and biodistribution) were used to estimate radiation dosimetry. Mini-thermoluminescent dosimetry (TLD) was also used to measure radiation dosimetry directly for 7 days after injection of 131I-Lym-1. Tumor size, survival, body weight, and blood counts were monitored for 60 days to evaluate therapeutic efficacy and toxicity of 131I-Lym-1. RESULTS: At the time of injection, the mean quality assurance (QA) values for 125I-Lym-1 were 100% monomer and 100% relative immunoreactivity; the corresponding values for 131I-Lym-1 were 73% and 66%, indicating that radiolysis had occurred during the interval between radiolabeling and injection. 125I-Lym-1 exhibited high and sustained concentration in tumors relative to normal organs, whereas 131I-Lym-1 did not. Assuming identical pharmacokinetic behavior to 125I-Lym-1, 131I-Lym-1 would deliver radiation doses of 3.45, 0.83, 1.03, 0.34, and 0.56 Gy per MBq injected (12.8, 3.1, 3.8, 1.3, and 2.1 rad/microCi), to tumor, liver, lungs, total body, and marrow, respectively. When the actual pharmacokinetic data for 131I-Lym-1 (1.5 MBq) were used to estimate dosimetry, corresponding values of 0.51, 0.72, 0.49, 0.31, and 0.41 Gy/MBq (1.9, 2.7, 1.8, 1.1, and 1.5 rad/microCi) were obtained. Similar values were obtained for mice receiving 7.4 or 14.8 MBq of 131I-Lym-1. Similarly, TLD data indicated little preferential radiation dosimetry to tumor. Response rates (cure + CR + PR) for mice receiving 0, 7.4, 14.8, and 18.5 MBq of 131I-Lym-1 were 8%, 7%, 21%, and 45%, respectively. The LD50/30 dose of 131I-Lym-1 was 12.7 MBq (343 microCi). CONCLUSIONS: 125I-Lym-1 exhibited high and sustained concentration in Raji tumors in mice, indicating excellent therapeutic potential for 131I-Lym-1. However, in vitro QA results for 131I-Lym-1 indicated that radiolysis had occurred, and 131I-Lym-1 demonstrated little accumulation in tumor, or preferential radiation dosimetry to tumor in the same model.

[Clinical efficacy of levofloxacin (LVFX) single-dose therapy in female acute uncomplicated cystitis].

Treatment of infections by the use of antimicrobial agents should be made essentially in a dose close to the minimally required dose. Acute uncomplicated cystitis in female fits as the subject for a single-dose therapy since it is an infection reactive relatively easily to antimicrobial agents. Accordingly, an assessment has been made regarding the therapeutic results of the single-dose therapy in 76 female cases of acute uncomplicated cystitis by the use of LVFX 200 mg which is a new quinolone. The urinary concentration more than MIC90 to Escherichia coli is sustained for about 3 days by this single-dose therapy. As a result of judging the therapeutic results from the reactions of the three clinical findings of pain on micturition, pyuria and bacteriuria, excellent therapeutic results were obtained with effective rates being 100% (76/76) on the day 3, 93.9% (46/49) on the day 7 and 94.4% (34/36) on the day 14. The rate of cystitic symptoms which recurred posed no problem, being 12.5% (5/40) up to three months, as investigated by a questionnaire. As a result of performing close urological examinations such as cystoscopy on six cases with insufficient results or recurrence, we could detect mild underlying conditions which are considered to be intractable factors in the bladder in three cases. From the above results, the single-dose therapy of acute uncomplicated cystitis in the female by LVFX which is a new quinolone was considered to be an excellent therapeutic drug from its characteristics such as its therapeutic results being the same as the conventional therapy by daily administration, excellent drug compliance, low cost, hard selectiveness of resistant strains, less side effects and furthermore it gives the opportunity of detecting a latent and mild underlying condition.

[Dose finding study of sparfloxacin in single-dose therapy for female acute uncomplicated cystitis].

Sparfloxacin (SPFX) is a new quinolone compound with a long half-life of 16 hours and a potent antibacterial activity (MIC90: < or = 0.025 micrograms/ml against Escherichia coli), suggesting that the agent can be effectively used in single-dose therapy for acute uncomplicated cystitis in female patients. To find the optimum dose, the present dose-finding study was conducted. A dose of either 100 mg or 200 mg of SPFX was selected by the double-blind method, and was administered only once (single dose therapy). The clinical efficacy was judged on day 3, 7 and 14 after administration. On day 3, of the 49 pts. in the 100 mg-group, the efficacy rate was 95.9% (excellent rate: 79.6%), and of the 42 pts. in the 200 mg-group, it was 100% (excellent rate: 88.1%). On day 7, of 38 pts. in the 100 mg-group, it was 94.7% (excellent rate: 78.9%), and of 28 pts. in the 200 mg-group, it was 100% (excellent rate: 92.9%). On day 14, of 27 pts. in the 100 mg-group, it was 92.6% (excellent rate: 66.7%), and of 26 in the 200 mg-group, it was 96.2% (excellent rate: 84.6%). Recurrence was observed in 4.8% (1/21) in the 200 mg-group. Therefore, there was no significant difference in the efficacy rate between the two groups, but the rate of excellent responses was higher in the 200 mg-group. Otherwise, the efficacy was estimated to be insufficient in 3 pts. and recurrent in 1 pt. they were examined the findings of detailed urological intractableness. Among 2 pts. in whom the external genitalia and urethra were closely examined, a urethral caruncle was noted in 1 pt. The results of our study indicate that 200 mg of SPFX is recommended as a single dose therapy for acute uncomplicated cystitis in females.

[Two cases of so-called extragonadal germinal tumor with "probable" retroperitoneal origin].

In a rare case of germinal tumor, the patient usually presents complaining of an abdominal mass as an initial symptom without an apparent tumor in his testis. Clinical strategy for such patients is based on that for testicular cancer. However, it often fails to produce a satisfactory response. The poor response may contribute to several "poor prognostic feature" found in most of these patients.

[Clinical study of tumor markers in prostatic carcinoma--an investigation on the simultaneous measurement of prostatic acid phosphatase (PAP), prostatic antigen (PA) and gamma-seminoprotein (gamma-Sm)].

Measurements of prostatic acid phosphatase (PAP), prostatic antigen (PA) and gamma-seminoprotein (gamma-Sm) have been found to be clinically useful in the diagnosis of prostatic carcinoma, but, the usefulness of simultaneous measurement has not yet been elucidated. We determined the clinical significance of simultaneous measurement of these markers, especially, the additional measurement of PA or gamma-Sm to PAP in prostatic carcinoma. Each measurement of PAP, PA and gamma-Sm yielded a very low "false" positive rate (0-6.5%) in patients with non-prostatic urogenital disease or benign prostatic hypertrophy (BPH), which was consistent with the results reported so far by other researchers. Eighteen patients with newly diagnosed prostatic carcinoma of a low stage showed a positive rate of PAP in 16.7%, PA in 33.3% and gamma-Sm in 38.9%. Forty patients having a high stage had a positive rate of 67.5% for each of the markers. In patients with BPH, the positive rate was elevated in only 2.6, 5.2 or 3.9% by the additional measurement of PA or gamma-Sm to PAP, or that of gamma-Sm to PA, respectively. This implied that the additional measurement of other markers to PAP or PA produced only a low elevation of the "false" positive rate. The positive rate in patients with prostatic carcinoma of low stage was increased by the additional measurement of PA or gamma-Sm to PAP or that of gamma-Sm to PA. This suggests that in patients with low stage carcinoma, assay with these combinations would be clinically useful to monitor the patient's clinical course.(ABSTRACT TRUNCATED AT 250 WORDS)

[Immunosuppressive acidic protein (IAP) and immunosuppressive substance (ISS) in patients with renal cell carcinoma].

To clarify their usefulness as markers for renal cell carcinoma, serum immunosuppressive acidic protein (IAP) and serum immunosuppressive substance (ISS) were evaluated by TIA (turbidometric immunoassay) for IAP and by SRID (single radial immunodiffusion) for ISS. The mean level of IAP and ISS was beyond each upper normal limit (500, 700 micrograms/ml) in every stage, and especially high in the M1 group. The levels of IAP and ISS were significantly correlated with each other. The determination of IAP and ISS levels after treatment showed a good correlation to the clinical course of the disease. The positive rates of IAP and ISS increased as the stages progressed, respectively. When the influences of pretreatment IAP and ISS level on survival period were investigated, the low IAP or ISS level group (less than two times of the upper normal limit) tended to have a better prognosis than the high level group (more than two times of the upper normal limit) in the M1 patients. These findings suggested that IAP and ISS could be used as markers for monitoring a disease and predicting the prognosis in patients with renal cell carcinoma. As for the positive rate in the combination assay for IAP, TPA and ferritin, or ISS, TPA and ferritin, more than 80% of the patients with low stage renal cell carcinoma had at least one positive marker. This suggested that the combination assay of these three markers was clinically valuable as a disease monitor in patients with renal cell carcinoma.

[Histopathological analysis of chemical carcinogenesis process by streptozotocin in the mouse kidney].

Renal adenocarcinoma was induced in CBA/H/T6J mice by a single intraperitoneal injection of 250 mg/kg of streptozotocin (STZ). Light and electron microscopic examination revealed that the carcinoma was a granular cell type-adenocarcinoma with abundant microvilli, basal lamina and intermediate junction indicating an epithelial cell origin. In histopathological analysis of the process of this carcinogenesis, all of the kidneys examined had a dilatation of proximal tubules in the second month and thereafter. In the fifth month, one of eight kidneys developed an adenoma. The adenoma was found in all the kidneys after the ninth month. An adenocarcinoma developed in one of the 14 kidneys in the twelfth month and in all others in the fifteenth month. In vivo labeling of bromodeoxyuridine on the cells in various stages demonstrated an increase of the labeling index which paralleled with progression of the carcinogenesis process. This finding in in vivo analysis of cell proliferation also supports the idea that serial changes of the kidney which are histopathologically proven correspond to the carcinogenesis process. The original carcinoma (STZ-RCC) has serially been passed in vivo at the present. Intrasplenic injection of STZ-RCC yielded multiple macroscopic foci of metastasis in the liver. This indicates that STZ-RCC has a malignant potential. Thus, STZ-induced mouse renal adenocarcinoma can be applied to the model system to investigate carcinogenesis and biological behaviors of renal cell carcinoma.

[Selection of highly metastatic lines from streptozotocin-induced mouse renal adenocarcinoma and their in vivo metastatic or in vitro invasive potential].

We selected highly metastatic lines from mouse renal adenocarcinoma (STZ-RCC) chemically induced with streptozotocin. At eight weeks after an intrasplenic injections (IS injection) of original STZ-RCC, this procedure yielded metastatic foci in the liver, which we transplanted serially in syngeneic mice (STZ-HM1). STZ-HM1 was then injected into the spleen of a syngeneic mouse, which provided a source for further cycles of hepatic metastasis selection. Three cycles of selection for hepatic metastasis yielded a high hepatic metastasis line (STZ-HM3). Intravenous injection of the parent line (original STZ-RCC) yielded metastatic foci in the lung eight weeks later, which we also transplanted serially in syngeneic mice (STZ-PM1). The repeated IS injection of the cells was clearly responsible for the increase in the frequency of hepatic metastasis and the number of its nodules. In particular, STZ-HM3 was revealed to have more metastatic nodules in the liver ranging from 293 to 432 (median; 368) in all five mice at eight weeks after IS injection. STZ-PM1 had a significantly higher rate of pulmonary metastasis and more pulmonary metastatic nodules after intravenous injection than the parent line. These results confirm that the parent line, STZ-RCC, has a heterogeneity in the metastatic phenotype. In vitro invasion assay for STZ-RCC, STZ-HM1, -HM2 and -HM3 demonstrated that in vitro invasive potential was paralleled with in vivo hepatic metastasis potential. The result suggests that the invasion potential revealed by in vitro invasion assay is important in metastasis formation.

[Study on in vitro invasive potential of renal cell carcinoma cell lines and effect of growth factors (EGF and TGF-beta 1) on their in invasions].

Renal cell carcinomas (RCCs) frequently metastasize to distant organs in their clinical course. However, the mechanism of the metastasis had not been fully elucidated. In vitro invasion assay has been reported to be a rapid method for the evaluation of the invasive potential of various malignant cells. In vitro invasive potential of RCC has not been investigated by this method. Thus, in the present study, we first attempted to characterize the in vitro invasive potential of four human RCC cell lines which had been established in our institute. Secondly, we investigated the influence of two growth factors (EGF, TGF-beta 1) on the invasive potential of these cell lines when the two factors were applied as chemoattractants. SMKT-R-3 and R-4 cell lines showed more cell penetration through Matrigel than SMKT-R-1 and R-2 cell lines, suggesting that the former cell lines have higher invasive potential. While invasive potential varied in each cell line, it was enhanced by EGF in all cell lines. However, TGF-beta 1 suppressed the invasive potential of all four cell lines. These results suggest that two factors have different actions on the invasion of RCCs.