Jörn Kamradt

Surgery for Metastatic Urothelial Carcinoma with Curative Intent: The German Experience (AUO AB 30/05)

BACKGROUND Recent publications suggest a benefit from surgical removal of urothelial carcinoma metastases (UCM) for a subgroup of patients. OBJECTIVE We report the combined experience and outcome of patients undergoing resection of UCM gained at 15 uro-oncologic centers in Germany. DESIGN, SETTING, AND PARTICIPANTS Retrospective survey of 44 patients with distant UCM of the bladder or upper urinary tract who underwent complete resection of all detectable metastases in 15 different German uro-oncological centers between 1991 and 2008. INTERVENTION Resected metastatic sites were the following: retroperitoneal lymph nodes (56.8%), distant lymph nodes (11.3%), lung (18.2%), bone (4.5%), adrenal gland (2.3%), brain (2.3%), small intestine (2.3%), and skin (2.3%). Systemic chemotherapy was administered in 35 of 44 patients (79.5%) before and/or after UCM surgery. MEASUREMENTS Overall, cancer-specific and progression-free survival from time of diagnosis and metastasectomy of UCM. RESULTS AND LIMITATIONS Median survival from initial diagnosis of UCM and subsequent resection was as follows: overall survival, 35 mo and 27 mo; cancer-specific survival, 38 mo and 34 mo; and progression-free survival, 19 mo and 15 mo. Overall 5-yr survival from metastasectomy for the entire cohort was 28%. Seventeen patients were still alive without progression at a median follow-up of 8 mo. Seven patients without disease progression survived for >2 yr and remained free from tumor progression at a median follow-up of 63 mo. No significant prognostic factors could be determined due to the limited patient number. CONCLUSIONS Long-term cancer control and possible cure can be achieved in a subgroup of patients following surgical removal of UCM. Metastasectomy in patients with disseminated UCM remains investigational and should only be offered to those with limited disease as a combined-modality approach with systemic chemotherapy.

Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells.

BackgroundThis study evaluated the cytotoxic and antiproliferative efficacy of two well-characterized members of the Cecropin-family of antimicrobial peptides against bladder tumor cells and benign fibroblasts.MethodsThe antiproliferative and cytotoxic potential of the Cecropins A and B was quantified by colorimetric WST-1-, BrdU- and LDH-assays in four bladder cancer cell lines as well as in murine and human fibroblast cell lines. IC50 values were assessed by logarithmic extrapolation, representing the concentration at which cell viability was reduced by 50%. Scanning electron microscopy (SEM) was performed to visualize the morphological changes induced by Cecropin A and B in bladder tumor cells and fibroblasts.ResultsCecropin A and B inhibit bladder cancer cell proliferation and viability in a dose-dependent fashion. The average IC50 values of Cecropin A and B against all bladder cancer cell lines ranged between 73.29 μg/ml and 220.05 μg/ml. In contrast, benign fibroblasts were significantly less or not at all susceptible to Cecropin A and B. Both Cecropins induced an increase in LDH release from bladder tumor cells whereas benign fibroblasts were not affected. SEM demonstrated lethal membrane disruption in bladder cancer cells as opposed to fibroblasts.ConclusionCecropin A and B exert selective cytotoxic and antiproliferative efficacy in bladder cancer cells while sparing targets of benign murine or human fibroblast origin. Both peptides may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on benign cells.

Analysis of the vitamin D system in basal cell carcinomas (BCCs)

Using real-time PCR (LightCycler) and immunohistochemistry, we have analyzed expression of key components of the vitamin D system in basal cell carcinomas (BCCs) and normal human skin (NS). Increased VDR-immunoreactivity was demonstrated in BCCs using a streptavidin-peroxidase technique. RNA expression of vitamin D receptor (VDR) and of main enzymes involved in synthesis and metabolism of calcitriol (vitamin D-25-hydroxylase [25-OHase], 25-hydroxyvitamin D-1α-hydroxylase [1α-OHase], 1,25-dihydroxyvitamin D-24-hydroxylase [24-OHase]) was detected in BCCs and NS. Expression levels were determined as ratios between target genes (VDR, 1α-OHase, 25-OHase, 24-OHase) and the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as internal control. Median of mRNA ratios for VDR/GAPDH (BCCs: 16.54; NS: 0.00021), 1α-OHase/GAPDH (BCCs: 0.739; NS 0.000803) and 24-OHase/GAPDH (BCCs: 0.00585; NS 0.000000366) was significantly (Wilcoxon–Mann–Whitney U-test) elevated in BCCs. In contrast, median of mRNA ratio for 25-OHase/GAPDH (BCCs: 0.17; NS: 0.016) was not significantly altered in BCCs as compared to NS. Additionally, we report for the first time expression of 1α-OHase splice variants in BCCs and NS, that were detected using conventional RT-PCR. In conclusion, our findings provide supportive evidence for the concept that endogeneous synthesis and metabolism of vitamin D metabolites as well as VDR expression may regulate growth characteristics of BCCs. New vitamin D analogs that exert little calcemic side effects, their precursors, or inhibitors of 24-OHase may offer a new approach for the prevention or therapy of BCCs. The function of alternative transcripts of 1α-OHase that we describe here for the first time in BCCs and NS and their effect on activity level has to be investigated in future experiments.

Fast-track rehabilitation after robot-assisted laparoscopic cystectomy accelerates postoperative recovery.

There is evidence from large abdominal surgeries and some open cystectomy series that multifactorial fast‐track regimens shorten postoperative convalescence without any effect on morbidity and mortality. Such a regimen is of particular interest in combination with minimally invasive techniques, as early patient recovery demands for more rapid nutrition and mobilisation schemes. The present study, in a single institution, reports on the design, application and results of a fast‐track protocol in patients undergoing robot‐assisted laparoscopic cystectomy. There was no evidence of a higher incidence of complications with the fast‐track regimen and postoperative recovery was faster.

Genomic and Expression Analysis of the 3q25-q26 Amplification Unit Reveals TLOC1/SEC62 as a Probable Target Gene in Prostate Cancer

Gain at chromosome 3q25-q26 has been reported to commonly occur in prostate cancer. To map the 3q25-q26 amplification unit and to identify the candidate genes of amplification, we did fluorescence in situ hybridization and quantitative real-time PCR for gene copy number and mRNA expression measurements in prostate cancer cell lines and prostate cancer samples from radical prostatectomy specimens. The minimal overlapping region of DNA copy number gains in the cell lines could be narrowed down to 700 kb at 3q26.2. Of all positional and functional candidates in this region, the gene TLOC1/SEC62 revealed the highest frequency (50%) of copy number gains in the prostate cancer samples and was found to be up-regulated at the mRNA level in all samples analyzed. TLOC1/Sec62 protein was also shown to be overexpressed by Western blot analysis. Intriguingly, the TLOC1/SEC62 gene copy number was increased in prostate tumors from patients who had a lower risk of and a longer time to progression following radical prostatectomy. These findings make TLOC1/SEC62 the best candidate within the 3q amplification unit in prostate cancer. TLOC1/Sec62 protein is a component of the endoplasmic reticulum protein translocation machinery, whose function during prostate carcinogenesis remains to be determined. (Mol Cancer Res 2006;4(3):169–76)

Expression of retinoid-X receptors (-· ,-· ,-·) and retinoic acid receptors (-· ,-· ,-·) in normal human skin: an immunohistological evaluation

SummaryIncreasing evidence suggests that the retinoid-X receptors (RXR-· ,-· ,-·) play a crucial role in regulating the transcriptional activity of several steroid hormone receptors, including the receptors for retinoic acid (RAR-· ,-· ,-·), 1,25-dihydroxyvitamin D3 and thyroid hormone. We investigated the localization of the different types of RXR-· ,-· ,-· and RAR-· ,-· ,-· proteins in frozen sections of normal human skin (n = 12) in situ, applying recently raised corresponding specific monoclonal antibodies and an immunohistochemical technique that we established for the detection of these nuclear receptors. Our findings indicate that RXR-· ,-· ,-· and RAR-· ,-· ,-· proteins can be detected by immunohistochemistry in normal human skin. In contrast to RXR-· ,-· ,-· as well as RAR-· and RAR-· proteins that were consistently detected in cell layers of the viable epidermis, RAR-· was only focally demonstrated in single epidermal cells in three out of 12 biopsies analysed. Immunohistochemical labelling of RAR-· ,-· ,-· and RXR-· ,-· ,-· proteins in epidermal nuclei was also pronounced in the stratum granulosum, suggesting a function of RXR and RAR proteins in the transition from proliferation to differatiation in epidermal keratinocytes. Expression of RXRs and RARs in hair follicles, sebaceous glands and endothelial cell points to a biological function from these nuclear receptors to hair growth as well as to the physiology of sebaceous glands and endothelial cells.

Analysis of 1,25-Dihydroxyvitamin D3 Receptors (VDR. in Basal Cell Carcinomas

We have analyzed expression of 1,25-dihydroxyvitamin D(3) receptor (VDR) protein and mRNA in basal cell carcinomas (BCC) of human skin. VDR immunoreactivity in BCCs was compared with the staining pattern of the proliferation marker Ki-67 in the same tumors. Additionally, VDR staining was compared to staining pattern of apoptotic cells by terminal UTP nucleotide end labeling assay. Frozen sections of superficial type, nodular type, and fibrosing type BCCs were consistently immunoreactive for VDR (mAb 9A7gamma) with almost every tumor cell labeled (n = 15). In general, VDR staining was pronounced in peripheral tumor cells. VDR immunoreactivity was consistently stronger in tumor cells than in adjacent or unaffected epidermis. No visual correlation was found in BCCs comparing labeling patterns of Ki-67-positive or apoptotic cells and mAb 9A7gamma. VDR mRNA was increased in BCCs (n = 6) compared to normal human skin (n = 5), as revealed by reverse transcription-polymerase chain reaction analysis. Our findings indicate that VDR is strongly expressed in BCCs and may be involved in the growth regulation of this tumour, and VDR mRNA and protein are increased in BCCs as compared to normal human epidermis.

Silencing of the SEC62 gene inhibits migratory and invasive potential of various tumor cells

Sec62 is part of the protein translocation apparatus in the membrane of the endoplasmic reticulum (ER). In yeast, Sec62 participates in the post‐translational translocation of proteins into the ER, but its function in mammals remains elusive. Previously we described the amplification and over‐expression of the SEC62 gene in prostate cancer cell lines and the protein has been described as a potential target gene in prostate cancer. In the current study we show that in the tumor tissue of prostate cancer patients Sec62 protein levels are elevated compared with tumor‐free tissue derived from the same patients or from prostates of control group patients and that the higher Sec62 protein content correlates with an increasing de‐differentiation of the cells. Therefore, up‐regulation of Sec62 protein content indeed is a phenomenon associated with prostate cancer progression. Analysis of a multi‐tissue tumor array showed that in addition to prostate cancer, overproduction of Sec62 is observed in various other tumors, most significantly in tumors of the lung and the thyroid. To examine the tumor‐related functions of Sec62, we silenced the SEC62 gene in the prostate cancer cell‐line PC3 as well as in a set of other tumor cell‐lines with two different siRNAs. In general, after silencing of SEC62 the cell migration and the invasive potential of the cells was blocked or at least dramatically reduced while cell viability was hardly affected. Thus, the SEC62 gene may indeed be considered as a target gene in the therapy of various tumors.

Analysis of the vitamin D system in cutaneous malignancies.

1,25-dihydroxyvitamin D3, the biological active metabolite of vitamin D, has great impact on keratinocyte growth and differentiation, and consequently has already been successfully used in the therapy of hyperproliferative skin disorders. We have now characterized the key components of the vitamin D system (VDR, 1alpha-OHase, 24-OHase and 25-OHase) in cutaneous basal cell carcinomas (BCC) and squamous cell carcinomas (SCC), using immunohistochemical and quantitative real-time PCR techniques. Additionally, proliferative activity (Ki-67 expression), differentiation status (cytokeratin 10 and transglutaminase K expression), rate of apoptosis (TUNEL assay) and the abundance of the main heterodimerization partners of VDR (RXRs) was determined for these tumours and correlated with the components of the Vitamin D system. Our findings indicate that the Vitamin D system may be of high importance for the growth behaviour of BCCs and SCCs and that new vitamin D analogues that exert less calcaemic side effects may be effective in the prevention or treatment of these tumours.

A Randomised Phase 2 Study Combining LY2181308 Sodium (Survivin Antisense Oligonucleotide) with First-line Docetaxel/Prednisone in Patients with Castration-resistant Prostate Cancer

Castration-resistant prostate cancer (CRPC) is partially characterised by overexpression of antiapoptotic proteins, such as survivin. In this phase 2 study, patients with metastatic CRPC (n=154) were randomly assigned (1:2 ratio) to receive standard first-line docetaxel/prednisone (control arm) or the combination of LY2181308 with docetaxel/prednisone (experimental arm). The primary objective was to estimate progression-free survival (PFS) for LY2181308 plus docetaxel. Secondary efficacy measures included overall survival (OS), several predefined prostate-specific antigen (PSA)-derived end points, and Brief Pain Inventory (BPI) and Functional Assessment of Cancer Therapy-Prostate (FACT-P) scores. The median PFS of treated patients for the experimental arm (n=98) was 8.64 mo (90% confidence interval [CI], 7.39-10.45) versus 9.00 mo (90% CI, 7.00-10.09) in the control arm (n=51; p=0.755). The median OS for the experimental arm was 27.04 mo (90% CI, 19.94-33.41) compared with 29.04 mo (90% CI, 20.11-39.26; p=0.838). The PSA responses (≥ 50% PSA reduction), BPI, and FACT-P scores were similar in both arms. In the experimental arm, patients had a numerically higher incidence of grades 3-4 neutropenia, anaemia, thrombocytopenia, and sensory neuropathy. In conclusion, this study failed to detect a difference in efficacy between the two treatment groups.