Captopril restores transforming growth factor-beta type II receptor and sensitivity to transforming growth factor-beta in murine renal cell cancer cells

Marketed nonsteroidal anti-inflammatory agents, antihypertensives, and human immunodeficiency virus protease inhibitors: as-yet-unused weapons of the oncologists' arsenal

Experimental data indicate that several pharmacological agents that have long been used for the management of various diseases unrelated to cancer exhibit profound in vitro and in vivo anticancer activity. This is of major clinical importance, since it would possibly aid in reassessing the therapeutic use of currently used agents for which clinicians already have experience. Further, this would obviate the time-consuming process required for the development and the approval of novel antineoplastic drugs. Herein, both pre-clinical and clinical data concerning the antineoplastic function of distinct commercially available pharmacological agents that are not currently used in the field of oncology, ie, nonsteroidal anti-inflammatory drugs, antihypertensive agents, and anti-human immunodeficiency virus agents inhibiting viral protease, are reviewed. The aim is to provide integrated information regarding not only the molecular basis of the antitumor function of these agents but also the applicability of the reevaluation of their therapeutic range in the clinical setting.

Evidence for aldosterone-dependent growth of renal cell carcinoma

The aim if this study was to investigate the hypothesis that K-RAS 4A is upregulated in a mineralocorticoid-dependent manner in renal cell carcinoma and that this supports the proliferation and survival of some renal cancers. Expression of the K-RAS in renal tumour tissues and cell lines was examined by real-time PCR and Western blot and mineralocorticoid receptor, and its gatekeeper enzyme 11β-hydroxysteroid dehydrogenase-2 was examined by immunocytochemistry on a tissue microarray of 27 cases of renal cell carcinoma. Renal cancer cells lines 04A018 (RCC4 plus VHL) and 04A019 (RCC4 plus vector alone) were examined for the expression of K-RAS4A and for the effect on K-RAS expression of spironolactone blockade of the mineralocorticoid receptor. K-RAS4A was suppressed by siRNA, and the effect on cell survival, proliferation and activation of the Akt and Raf signalling pathways was investigated in vitro. K-RAS4A was expressed in RCC tissue and in the renal cancer cell lines but K-RAS was downregulated by spironolactone and upregulated by aldosterone. Spironolactone treatment and K-RAS suppression both led to a reduction in cell number in vitro. Both Akt and Raf pathways showed activation which was dependent on K-RAS expression. K-RAS expression in renal cell carcinoma is at least partially induced by aldosterone. Aldosterone supports the survival and proliferation of RCC cells by upregulation of K-RAS acting through the Akt and Raf pathways.

D-penicillamine and other low molecular weight thiols: review of anticancer effects and related mechanisms

Low molecular weight thiols (LMWTs) like N-acetyl cysteine, D-penicillamine, captopril, Disulfiram and Amifostine, etc. have been used as chemo-preventive agents. Recent studies have reported cell growth inhibition and cytotoxicity in several different types of cancer cells following treatment with several LMWTs. Cytotoxic and cytostatic effects of LMWTs may involve interaction of the thiol group with cellular lipids, proteins, intermediates or enzymes. Some of the mechanisms that have been proposed include a p53 mediated apoptosis, thiyl radical induced DNA damage, membrane damage through lipid peroxidation, anti-angiogenic effects induced by inhibition of matrix metalloproteinase enzymes and angiostatin generation. LMWTs are strong chelators of transition metals like copper, nickel, zinc, iron and cobalt and may cause metal co-factor depletion resulting in cytotoxicity. Oxidation of thiol group can also generate cytotoxic reactive oxygen species (ROS).

Inhibition of transforming growth factor-β release from tumor cells reduces their motility associated with epithelial-mesenchymal transition

The high level of transforming growth factor‑β (TGF‑β) in tumor tissue, which is primarily released from tumor cells, helps maintain their metastatic nature and exacerbates the creation of a pro-tumor microenvironment. Although the strategy of targeting TGF‑β in cancer therapy has shown promise, its effects remain limited. In the present study, we focused on tumor cells as sources of TGF‑β release, and hypothesized that inhibition of their TGF‑β release could suppress their epithelial-mesenchymal transition (EMT)-associated metastatic nature and inactivate the induction of suppressor immune cells. To investigate this hypothesis, LLC1 cells, a mouse lung cancer cell line, were cultured with the TGF‑β release inhibitor tranilast and the motility of LLC1 cells was examined. Furthermore, to examine whether inhibition of TGF‑β release influences the induction of regulatory T (Treg) cells, spleen cells from normal mice were cultured in medium in which LLC1 cells had been cultured with tranilast. The results showed that tranilast inhibited the release of TGF‑β1 from LLC1 cells without affecting their proliferation. Inhibition of TGF‑β1 release suppressed the invasive activity of LLC1 cells, but enhanced their activity to adhere. mRNA levels of Slug and Twist were decreased in LLC1 cells, whereas levels of E‑cadherin were recovered. Treg cells were less frequently induced by medium in which LLC1 cells had been cultured with tranilast. Taken together, inhibition of TGF‑β1 release dampens the metastatic nature of LLC1 cells through the downregulation of EMT and possesses the possibility to improve antitumor immune responses through suppression of Treg cell induction. These findings provide a new rationale for development of TGF‑β‑targeted molecular immunotherapy against cancer.

[Angiotensin-2 type 1 receptors (AT1R) and cancers]

Recently, several meta-analysis suggested an increased risk of cancers linked to the use of antagonists of angiotensin-2 receptors or inhibitors of angiotensinogen converting enzyme. The results of epidemiological studies are conflicting. Meta-analysis as well as retrospective studies are not reliable and biased, since they have never been designed to explore any pro- or antitumoral effect. We lack of prospective studies that could take off the doubt on these drugs. Nevertheless, all experimental researches pointed out potent antitumoral properties. Indeed, direct antiproliferative and neo-angiogenic inhibition have been described on tumor cell cultures as well as on animal models. Moreover, we are convinced that the use of antagonists of angiotensin-2 receptors and inhibitors of angiotensinogen converting enzyme may be then of clinical use in the near future in association with classical antitumor drugs. In this review, we proposed to explore these data by a thorough analysis of recent literature associating epidemiological and experimental studies.

Insertion/deletion polymorphism of angiotensin I-converting enzyme gene is linked with chromophobe renal cell carcinoma

OBJECTIVES

To study the putative significance of angiotensin I-converting enzyme (ACE) in renal cell carcinoma (RCC). Recent evidence has suggested that a 287-base pair insertion (I)/deletion (D) polymorphism (rs4646994) of the angiotensin I-converting enzyme (ACE) might be associated with cancer risk and progression.

METHODS

The present case-control study accrued 383 subjects, including 210 with RCC and 173 age- and sex-matched healthy individuals without evidence or a history of cancer. Genomic DNA was extracted from the peripheral blood leukocytes. The ACE fragment containing the polymorphism was amplified using conventional polymerase chain reaction using specific primer pairs and subsequently genotyped using agarose gel electrophoresis.

RESULTS

Overall, a DD genotype and D allele were more frequently noted in the patients with RCC than in the controls (P = .042 and P = .045, respectively), and resulted from a greater frequency of DD and D in chromophobe RCC (P = .023 and P = .020, respectively). In contrast, the genotype and allele distribution of the controls and patients with papillary or clear cell RCC was similar. The II genotype was not observed in any patient with chromophobe RCC. On multivariate logistic regression analysis, the ACE genotype was an independent risk factor for chromophobe RCC (P = .012). Neither the ACE genotypes or alleles were associated with the tumor stage or grade.

CONCLUSIONS

The results of the present study have shown for the first time that the ACE insertion/deletion gene polymorphism rs4646994 might be linked with the development of chromophobe RCC. Neither the ACE genotypes nor the alleles were associated with RCC progression.

Cancer control, continence, and potency after laparoscopic radical prostatectomy beyond the learning and discovery curves

PURPOSE

To investigate the results of laparoscopic radical prostatectomy (LRP) beyond the learning and discovery curves of 700 patients previously reported by the authors for potency.

PATIENTS AND METHODS

Five hundred consecutive patients underwent LRP during a 28-month period with a minimum follow-up of 12 months. Median age (with range) = 61.0 (33-76) years; prostate-specific antigen level = 7.0 (1-37); biopsy Gleason sum = 7 (4-10). Clinical stage was T1 in 41.0%, T2 in 54.2%, and T3 in 4.8%. Nerve preservation (NP) was performed bilaterally in 57.9%, unilaterally in 15.3%, and on neither side in 26.8%.

RESULTS

Median operative time was 157 (91-331) minutes, with no conversions or intraoperative blood transfusions; 0.4% of patients received a transfusion postoperatively, and 4.2% had complications. There were no rectal injuries. The overall positive margin rate was 13.0% and correlated with pathologic parameters. At a minimum of 1 year follow-up (mean=13.5 (12-36) mos), overall survival was 100%, and biochemical disease-free survival was 98.8%. The pad-free rate was 97.4%. Potency (International Index of Erectile Function-5 score ≥17) at a mean follow-up of 13.5 months in previously potent men in their 4th, 5th, 6th, and 7th decades after bilateral NP was 100.0%, 91.8%, 82.9%, and 60.0% and after unilateral NP was 100%, 66.7%, 50.1%, and 0.0%. Overall potency after bilateral neurovascular bundle NVB preservation was 86.9%.

CONCLUSION

LRP is capable of matching or exceeding the best results for open radical prostatectomy and robot-assisted radical prostatectomy when performed by an experienced surgeon in a high-volume setting. These results suggest that the method used to perform radical prostatectomy is a less important determinant of success than surgical experience.

Connection between inflammation and carcinogenesis in gastrointestinal tract: Focus on TGF-β signaling

Inflammation is a primary defense process against various extracellular stimuli, such as viruses, pathogens, foods, and environmental pollutants. When cells respond to stimuli for short periods of time, it results in acute or physiological inflammation. However, if the stimulation is sustained for longer time or a pathological state occurs, it is known as chronic or pathological inflammation. Several studies have shown that tumorigenesis in the gastrointestinal (GI) tract is closely associated with chronic inflammation, for which abnormal cellular alterations that accompany chronic inflammation such as oxidative stresses, gene mutations, epigenetic changes, and inflammatory cytokines, are shared with carcinogenic processes, which forms a critical cross-link between chronic inflammation and carcinogenesis. Transforming growth factor (TGF)-β is a multi-potent cytokine that plays an important role in regulation of cell growth, apoptosis and differentiation. Most importantly, TGF-β is a strong anti-inflammatory cytokine that regulates the development of effector cells. TGF-β has a suppressive effect on carcinogenesis under normal conditions by inhibiting abnormal cell growth, but on the other hand, many GI cancers originate from uncontrolled cell growth and differentiation by genetic loss of TGF-β signaling molecules or perturbation of TGF-β adaptors. Once a tumor has developed, TGF-β exerts a promoting effect on the tumor itself and stromal cells to enhance cell growth, alter the responsiveness of tumor cells to stimulate invasion and metastasis, and inhibited immune surveillance. Therefore, novel development of therapeutic agents to inhibit TGF-β-induced progression of tumor and to retain its growth inhibitory activities, in addition to anti-inflammatory actions, could be useful in oncology. In this review, we discuss the role of TGF-β in inflammation and carcinogenesis of the GI tract related to abnormal TGF-β signaling.

Drug development against metastasis-related genes and their pathways: a rationale for cancer therapy

It is well recognized that the majority of cancer related deaths is caused by metastatic diseases. Therefore, there is an urgent need for the development of therapeutic intervention specifically targeted to the metastatic process. In the last decade, significant progress has been made in this research field, and many new concepts have emerged that shed light on the molecular mechanism of metastasis cascade which is often portrayed as a succession of six distinct steps; localized invasion, intravasation, translocation, extravasation, micrometastasis and colonization. Successful metastasis is dependent on the balance and complex interplay of both the metastasis promoters and suppressors in each step. Therefore, the basic strategy of our interventions is aimed at either blocking the promoters or potentiating the suppressors in this disease process. Toward this goal, various kinds of antibodies and small molecules have been designed. These include agents that block the ligand-recepter interaction of metastasis promoters (HGF/c-Met), antagonize the metastasis-promoting enzymes (AMF, uPA and MMP) and inhibit the transcriptional activity of metastasis promoter (beta-Catenin). On the other hand, the intriguing roles of metastasis suppressors and their signal pathways have been extensively studied and various attempts have been made to potentiate these factors. Small molecules have been developed to restore the expression or mimic the function of metastasis-suppressor genes such as NM23, E-cadherin, Kiss-1, MKK4 and NDRG1, and some of them are under clinical trials. This review summarizes our current understanding of the molecular pathway of tumor metastasis and discusses strategies and recent development of anti-metastatic drugs.

Actions of TGF-beta as tumor suppressor and pro-metastatic factor in human cancer

Transforming growth factor-beta (TGF-beta) is a secreted polypeptide that signals via receptor serine/threonine kinases and intracellular Smad effectors. TGF-beta inhibits proliferation and induces apoptosis in various cell types, and accumulation of loss-of-function mutations in the TGF-beta receptor or Smad genes classify the pathway as a tumor suppressor in humans. In addition, various oncogenic pathways directly inactivate the TGF-beta receptor-Smad pathway, thus favoring tumor growth. On the other hand, all human tumors overproduce TGF-beta whose autocrine and paracrine actions promote tumor cell invasiveness and metastasis. Accordingly, TGF-beta induces epithelial-mesenchymal transition, a differentiation switch that is required for transitory invasiveness of carcinoma cells. Tumor-derived TGF-beta acting on stromal fibroblasts remodels the tumor matrix and induces expression of mitogenic signals towards the carcinoma cells, and upon acting on endothelial cells and pericytes, TGF-beta regulates angiogenesis. Finally, TGF-beta suppresses proliferation and differentiation of lymphocytes including cytolytic T cells, natural killer cells and macrophages, thus preventing immune surveillance of the developing tumor. Current clinical approaches aim at establishing novel cancer drugs whose mechanisms target the TGF-beta pathway. In conclusion, TGF-beta signaling is intimately implicated in tumor development and contributes to all cardinal features of tumor cell biology.

Role of transforming growth factor Beta in human cancer

Transforming growth factor beta (TGF-beta) is a ubiquitous and essential regulator of cellular and physiologic processes including proliferation, differentiation, migration, cell survival, angiogenesis, and immunosurveillance. Alterations in the TGF-beta signaling pathway, including mutation or deletion of members of the signaling pathway and resistance to TGF-beta-mediated inhibition of proliferation are frequently observed in human cancers. Although these alterations define a tumor suppressor role for the TGF-beta pathway in human cancer, TGF-beta also mediates tumor-promoting effects, either through differential effects on tumor and stromal cells or through a fundamental alteration in the TGF-beta responsiveness of the tumor cells themselves. TGF-beta and members of the TGF-beta signaling pathway are being evaluated as prognostic or predictive markers for cancer patients. Ongoing advances in understanding the TGF-beta signaling pathway will enable targeting of this pathway for the chemoprevention and treatment of human cancers.

Impact of Learning Curve in Laparoscopic Radical Prostatectomy on Margin Status: Prospective Study of First 100 Procedures Performed by One Surgeon

PURPOSE

To describe the experience of a single surgeon with his first 100 laparoscopic radical prostatectomies and determine the impact of the learning curve on the surgical margin status according to the rate of nervesparing procedures.

PATIENTS AND METHODS

Between December 2000 and April 2002, 100 laparoscopic radical prostatectomies were performed by one surgeon without any selection of patients and without the help of any other surgeon. The procedures were divided in four groups of 25 consecutive cases. There was no significant difference among the groups in terms of age, clinical and pathological stage, or Gleason score. Nerve-sparing (NS) dissection was performed when the procedure was easy. Positive surgical margins (SM+) were measured and classified according to their location.

RESULTS

The overall rate of SM+ was 12.8% in pT2 and 31.8% in pT3 tumors. The SM+ rate was not significantly different among the groups. In contrast, the number of NS dissections (49 patients) increased from group 1 to group 4. Both the positive margin length and the rate of multiple positive margins were significantly lower in the 50 most recent patients.

CONCLUSION

Nerve-sparing surgery was performed with increasing frequency during this learning curve without compromising the surgical margins. The results suggest that experience could lead to a decrease of both the positive margin length and the rate of multiple positive margins. The impact on cancer control and potency is under evaluation.

Loss of expression of transforming growth factor-beta receptor as a prognostic factor in patients with renal cell carcinoma

OBJECTIVES

To determine the clinical implication of the loss of transforming growth factor-beta (TGF-beta) receptor (TbetaR) expression for the pathologic features in renal cell carcinoma (RCC) and the prognosis of 62 patients (Stage I, 4; Stage II, 28; Stage III, 11; and Stage IV, 19) who underwent radical nephrectomy for RCC. Loss of expression in TbetaR could result in escape from the growth inhibitory effect of TGF-beta in TGF-beta-secreting cancer.

METHODS

TbetaR and apoptosis in the tumor were detected by immunohistochemistry using samples from 62 patients. We statistically investigated the relationship among the TbetaR expression pattern, pathologic features, and the prognosis of patients with RCC.

RESULTS

A loss of expression of TbetaR-I and TbetaR-II was identified in 29 patients (46.7%) and 31 patients (50.0%), respectively. Although the loss of TbetaR-I was not associated with clinical stage, the loss of TbetaR-II was associated with clinical stage (P <0.01). Univariate analysis of all patients demonstrated that Stage T3 or greater, clinical Stage III or greater, loss of TbetaR-II, and a tumor apoptotic index of less than 35 were associated with a significantly lower survival rate than their respective counterparts. Multivariate analysis showed that the only two significant prognostic factors were clinical stage and loss of TbetaR-II. In addition, TbetaR-negative RCC had significantly lower apoptosis than did TbetaR-positive RCC.

CONCLUSIONS

These results suggest that a loss of TbetaR-II expression in the primary tumor is a significant prognostic factor in patients with RCC.