Progression of Intravesical Condyloma Acuminata to Locally Advanced Poorly Differentiated Squamous Cell Carcinoma

Condyloma acuminata (CA) is a common sexually transmitted disease caused by Human Papilloma Virus (HPV) infection. CA of the bladder, however, is an exceedingly rare lesion. We present a rare case of poorly differentiated locally invasive squamous cell carcinoma (SCC) arising from recurrent CA of the bladder in an immunocompetent patient and discuss pathophysiology and management of this unusual condition.

The efficacy and safety of synchronous bilateral extracorporeal shock wave lithotripsy

PURPOSE

Bilateral renal calculi have traditionally been managed by staged extracorporeal shock wave lithotripsy (ESWLdagger) due to concern about bilateral obstruction. We evaluated the safety and efficacy of synchronous bilateral ESWL in a large series of patients treated at our institution to determine the safety and efficacy of this controversial technique in what is to our knowledge the largest series to date.

MATERIALS AND METHODS

We retrospectively evaluated the records of 120 patients with a mean age of 48 years who underwent bilateral synchronous ESWL between 1987 and 1996. Of the patients 71 (59%) were male. Average followup was 21 months. ESWL was performed using a Dornier HM3 lithotriptor in all cases. Intraoperative technique and postoperative factors were analyzed using the Pearson product moment correlation, the 2-tailed t test and multiple regression analysis.

RESULTS

Mean stone size was 13 and 15 mm. on the left and right sides, respectively. There was an average of 1.7 stones per renal unit. After 1 treatment 72 of the 120 patients (60%) were stone-free bilaterally, while 72% and 73% of left and right renal units, respectively, were also stone-free. Mean creatinine was similar preoperatively and postoperatively (1.46 and 1.41 mg./dl., respectively, p = 0.73). There was 1 or more complications in 18 cases. The majority of complications were minor with no long-term morbidity or death and there was no case of bilateral obstruction or renal failure. Additional procedures were required in 19 patients (16%) due to significant residual stone disease or obstruction during followup. Multiple regression analysis revealed that only patient age, a right ureteral stent and the number of shocks correlated with the complication rate. Stone size and number independently increased the probability of treatment failure and a repeat procedure (p <0.05). Patients with stones 20 mm. or greater were at particularly high risk for treatment failure and additional procedures. A total of 27 of the 35 patients (77%) with residual calculi and 13 of the 19 (68%) requiring additional procedures were in this high risk subgroup.

CONCLUSIONS

Bilateral synchronous ESWL is safe and effective monotherapy for bilateral urolithiasis. No patient had bilateral obstruction or renal failure and no deterioration of renal function was detected at followup. Knowing which patient populations are at higher risk for failure or complications may guide decision making.

Down-regulation of TGF-beta1 production restores immunogenicity in prostate cancer cells

The objective of this study is to determine if a non-immunogenic Dunning's rat prostate cancer cell line, MATLyLu, can become immunogenic by reducing the endogenous production of TGF-beta1. An expression construct containing a DNA sequence in an antisense orientation to TGF-beta1 (TGF-beta1 antisense) was stably transfected into MATLyLu cells. Following transfection, cellular content of TGF-beta1 reduced from 70 to 10 pg per 2x10(4) cells and the rate of in vitro 3H-thymidine incorporation increased 3-5-fold. After subcutaneous injection of tumour cells into syngeneic male hosts (Copenhagen rats), the tumour incidence was 100% (15/15) for the wild type MATLyLu cells and cells transfected with the control construct, but only 43% (9/21, P< or =0.05) for cells transfected with TGF-beta1 antisense. However, when cells were injected into immunodeficient hosts (athymic nude rats), the incidence of tumour development was 100% (10/10) for both the wild type MATLyLu cells and cells transfected with the control construct and 90% (9/10) for cells transfected with TGF-beta1 antisense. These observations support the concept that MATLyLu cells are immunogenic, when the endogenous production of TGF-beta1 is down-regulated.

Absence of proximal duct apoptosis in the ventral prostate of transgenic mice carrying the C3(1)-TGF-beta type II dominant negative receptor

BACKGROUND

Prostatic epithelial cells are sensitive to the inhibitory effects of TGF-beta. However, TGF-beta signaling in the prostate is dependent on androgenic status. Under the in vivo conditions, it is difficult to dissociate the effect of TGF-beta from that of androgen on the prostate.

METHODS

The objective of the present study was to create and verify a transgenic mouse system in which epithelial cells of the ventral prostate are insensitive to the actions of TGF-beta. By using a modified prostate-specific promoter, C3(1), the TGF-beta dominant negative receptor is only expressed in the epithelial cells of the ventral prostate, and these cells are resistant to TGF-beta. Morphology of transgenic animal prostates was compared to wild-type animal prostates by immunohistochemistry and microscopy.

RESULTS

The prostate of transgenic mice exhibited an abnormal morphology with multiple layers of epithelial cells lining the proximal ducts, in contrast to the simple cuboidal monolayer of cells seen in the normal prostate. This observation was accompanied by a loss of apoptosis in this region, as seen by TUNEL assay. There was no significant difference in serum levels of testosterone between the wild-type and transgenic animals.

CONCLUSIONS

These results demonstrated that a loss of sensitivity to TGF-beta results in the accumulation of multiple layers of epithelial cells in the proximal region of the ventral prostate. This abnormal growth illustrates that TGF-beta plays an important role in regulating prostate growth. The current transgenic system can be used as an experimental model to study the functional role of TGF-beta in prostatic growth and function.

Transforming growth factor-beta type II receptor confers tumor suppressor activity in murine renal carcinoma (Renca) cells

OBJECTIVES

To demonstrate that the introduction of the transforming growth factor-beta (TGF-beta) type II receptor (TbetaR-II) decreases tumorigenicity in an aggressive murine renal carcinoma line, Renca. These cells do not express TbetaR-II. Because the presence of TbetaR-II in benign epithelial cells is ubiquitous, the ability to restore tumor suppressor activity in the Renca cell line with its introduction would elucidate the role of TbetaR-II as a tumor suppressor gene.

METHODS

Renca cells were stably transfected with a retrovirus-mediated TbetaR-II expression vector. In vitro sensitivity to growth inhibitory effect of TGF-beta was assessed by the 3H-thymidine incorporation assay. For in vivo testing, xenograft tumors were produced by subcutaneous injection of tumor cells into immunodeficient nude mice. The tumorigenicity of these TbetaR-II transfected cells was tested. Wild-type Renca cells and cells transfected with the control vector were also tested for comparison.

RESULTS

Expression of TbetaR-II mRNA was evident in Renca cells after transfection with the TbetaR-II construct. In vitro sensitivity to the growth inhibitory effect of TGF-beta was restored. This effect of TGF-beta was reversible with a neutralizing antibody specific for the extracellular domain of TbetaR-II. Xenografts grown from TbetaR-II transfected cells were significantly smaller, weighed less, and developed tumors later than those developed from wild-type Renca cells and those transfected with the control vector.

CONCLUSIONS

We conclude that TbetaR-II is a central mediator of tumorigenicity in Renca cells. As with other tumor suppressor genes, the loss of TbetaR-II expression allows for the development of an aggressive phenotype.

Transforming growth factor-beta in benign and malignant prostate

BACKGROUND

The present review summarizes the cellular action of TGF-beta in benign and malignant growth of the prostate.

METHODS

TGF-beta is a pleiotropic growth factor. It plays an important role in the regulation of growth and differentiation in many cells. In benign prostatic epithelia, its action is mediated through a paracrine mechanism. It inhibits proliferation and induces apoptosis in prostatic epithelia. It provides a mechanism to maintain epithelial homeostasis in the prostate. In prostatic stroma, its continual action leads to smooth muscle differentiation. This effect of TGF-beta may regulate the development of prostatic smooth muscle nodules in benign prostatic hyperplasia.

RESULTS

As prostatic epithelial cells undergo malignant transformation, two major events occur regarding TGF-beta action. These include the loss of expression of functional TGF-beta receptors and overproduction of TGF-beta in malignant cells. The loss of expression of functional TGF-beta receptors provides a growth advantage to cancer cells over their benign counterparts. The overproduction of TGF-beta by cancer cells has a multitude of adverse consequences. TGF-beta can promote extracellular matrix production, induce angiogenesis, and inhibit host immune function. The biological consequence of these activities is an enhanced tumorigenicity in prostate cancer. Results of our recent studies with a rat prostate cancer model suggest that the immunosuppressive effect of TGF-beta seems to be the primary cause of tumor progression. This is because, if these cancer cells were engineered to reduce the production of TGF-beta, tumor growth was inhibited in syngeneic hosts but not in immune compromised hosts.

CONCLUSIONS

Our future research should take advantage of this knowledge to devise therapeutic strategies aimed at eradicating prostate cancer.

Absence of expression of transforming growth factor-beta type II receptor is associated with an aggressive growth pattern in a murine renal carcinoma cell line, Renca

Transforming growth factor-beta1 (TGF-beta1) inhibits the proliferation of many cancer cells. However, tumor cells frequently become resistant to this inhibitory effect due to the absence of TGF-beta receptor (TbetaR) expression. This study reports the nature of TGF-beta sensitivity in an aggressive murine renal carcinoma cell line, Renca, investigated in a series of experiments. The growth of Renca cells, in tissue culture, was not sensitive to the inhibitory effect of TGF-beta1 with doses ranging from 0.1 to 10 ng./ml., nor was this cell line sensitive to the effect of TGF-beta1 in inducing the expression of plasminogen activator inhibitor-I. Renca cells expressed TGF-beta1 mRNA and protein, as determined by RT-PCR and ELISA, respectively. The level of TGF-beta1 production by Renca cells was moderate, thus eliminating the possibility that endogenous TGF-beta1 production might be masking the effect of TGF-beta sensitivity. Furthermore, Renca cells expressed TbetaR-I mRNA, but did not express TbetaR-II mRNA, suggesting that the absence of this receptor may be the cause of TGF-beta insensitivity. Additionally, a vector containing the TbetaR-II cDNA was transiently transfected into Renca cells. The inhibitory effect of TGF-beta1 was introduced in Renca cells after transfection with this receptor. At the same time, the growth rate of these cells diminished significantly when compared with that of the wild type Renca cells, as judged by the rate of [3H]-thymidine incorporation in the absence of any exogenous TGF-beta1. These observations demonstrated that Renca cells lack the functional TbetaR-II and suggest that their aggressive growth pattern is due, at least in part, to their insensitivity to TGF-beta.