Ralph de Vere White

MicroRNA in prostate, bladder, and kidney cancer: A systematic review

CONTEXT MicroRNAs (miRNA) are noncoding RNAs that post-transcriptionally regulate gene expression. Their altered expression and function have been observed in most urologic cancers. MiRNAs represent potential disease biomarkers and novel therapeutic targets. OBJECTIVE To review and evaluate the evidence implicating miRNAs in the pathogenesis of prostate cancer (PCa), bladder cancer (BCa), and renal cancer. EVIDENCE ACQUISITION A systematic review was performed using PubMed and Embase to search for reports using strings for microRNA, non-coding RNA, cancer, prostate, bladder, and renal cancer. Identified manuscripts were retrieved and references searched. Selected studies were required to concentrate on the role of miRNA in these urologic cancers. EVIDENCE SYNTHESIS We reviewed articles that focus on this topic. More than 40 miRNAs have been implicated in urologic cancer and many target common carcinogenic pathways. In particular, apoptosis avoidance, cell proliferation, epithelial-to-mesenchymal transition, angiogenic signalling, and the generation of androgen independence are targeted or facilitated by more than one miRNA. Little work has been done to evaluate the translational applications for this knowledge to date. Novel therapeutic strategies have been developed and are under investigation to selectively modulate miRNAs; such work would potentially enable personalised tumour therapy. CONCLUSIONS MiRNAs appear to be important modulators of urologic cancer. Their expression is frequently altered in these tumours, and many are functionally implicated in their pathogenesis. They require evaluation to determine the translational role and therapeutic potential for this knowledge.

Down-regulation of microRNA 106b is involved in p21-mediated cell cycle arrest in response to radiation in prostate cancer cells.

microRNAs (miRNAs) are endogenous short non‐coding RNAs, and play a pivotal role in regulating of a variety of cellular processes, including proliferation and apoptosis, both of which are cellular responses to radiation treatment. The purpose of this study is to identify candidate miRNAs whose levels are altered in response to radiation in prostate cancer cells and to investigate the molecular pathway of such miRNAs in the regulation of radiation‐induced cellular response.

Glycomic Approach for Potential Biomarkers on Prostate Cancer: Profiling of N-Linked Glycans in Human Sera and pRNS Cell Lines

Prostate cancer is a leading cause of cancer death among men. Currently available screening test measures prostate-specific antigen (PSA) to detect prostate cancer. However, this test produces false positive values that often lead to negative biopsies. Therefore, a more reliable diagnostic tool is needed. Glycans in serum are of particular interest as around half of all proteins are glycosylated. In this study, N-linked glycans were enzymatically released by PNGase F from prostate epithelial cell lines (pRNS) expressing wild type or mutant androgen receptors and a small set of human serum samples. Released glycans were purified and partitioned into neutral and acidic components by solid phase extraction (SPE) using graphitized carbon cartridges. The SPE fractions were analyzed by matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI FT-ICR MS). Significant changes in some high-mannose and fucosylated biantennary complex N-linked glycans were observed in the serum of prostate cancer patients.

Near-infrared autofluorescence imaging for detection of cancer

Near-infrared autofluorescence imaging of tissues under long-wavelength laser excitation in the green and red spectral region complemented by cross-polarized elastic light scattering was explored for cancer detection. Various types of normal and malignant human tissue samples were utilized in this investigation. A set of images for each tissue sample was recorded that consisted of two autofluorescence images obtained under 532- and 632.8-nm excitation and light-scattering images obtained under linearly polarized illumination at 700, 850, and 1000 nm. These images were compared with the histopathology of the tissue sample. The experimental results indicated that for various tissue types, the intensity of the autofluorescence integrated over the 700 to 1000-nm spectral region was considerably different in cancer tissues than in that of the contiguous non-neoplastic tissues. This difference provided the basis for the detection of cancer and delineation of the tumor margins. Variations on the relative intensity were observed among different tissue types and excitation wavelengths.

Identification of a bladder cancer-specific ligand using a combinatorial chemistry approach

OBJECTIVES To develop bladder cancer-specific ligands using a combinatorial chemistry approach. MATERIALS AND METHODS We performed a high-throughput one-bead one-compound combinatorial chemistry approach to identify ligands that bound to bladder transitional cell carcinoma cells. The whole-cell binding assay allowed successful identification of a few peptides that bound selectively to bladder cancer cells. Single cell suspensions derived from clinical bladder cancer specimens and cell lines were used to determine the binding specificity. Studies with mouse xenografts were performed to determine the in vivo binding and targeting efficiency, specificity, and biodistribution of one of the ligands. RESULTS One cyclic peptide named PLZ4 (amino acid sequence: cQDGRMGFc) was identified that could selectively bind to bladder cancer cell lines and all of the 5 primary bladder cancer cells from human patients, but not to normal urothelial cells, cell mixtures from normal bladder specimens, fibroblasts, and blood cells. Comparison of PLZ4 binding to cell lines of different cancer origins showed that it was bladder cancer-specific (P < 0.05). PLZ4 could bind to tumor cells treated with urine at pH 6.0, but not to noncancerous cells collected from the urine of 4 patients actively being treated with intravesical Bacillus Calmette-Guerin therapy. In vivo and ex vivo imaging studies showed that PLZ4 linked to Cy5.5 fluorescent dye administered via tail vein injection was specifically taken up in mouse xenografts developed from excised fresh human bladder cancer specimens. Several ligands contain the same DGR motif, but only PLZ4 was bladder cancer-specific. We performed alanine walk and rainbow bead coding experiments, and found that the C-terminal GF residues were also important for cell binding and modulated the binding specificity. CONCLUSIONS PLZ4 has the potential to be used for targeted therapy and imaging detection during diagnosis and follow-up/surveillance of noninvasive and advanced bladder cancer.

Spectroscopic detection of bladder cancer using near-infrared imaging techniques

High-contrast imaging of bladder cancer is demonstrated using near-infrared autofluorescence under long-wavelength laser excitation in combination with cross-polarized elastic light scattering. Fresh unprocessed surgical specimens obtained following cystectomy or transurethral resection were utilized and a set of images for each tissue sample was recorded. These images were compared with the histopathology of the tissue sample. The experimental results indicate that the intensity of the near-infrared emission as well as that of the cross-polarized backscattered light was considerably different in cancer tissues than in that of the contiguous nonneoplastic tissues, allowing an accurate delineation of a tumors margins.

Tumor-targeting multifunctional micelles for imaging and chemotherapy of advanced bladder cancer

AIM This work aimed to determine if the treatment outcomes of bladder cancer could be improved by targeting micelles that are decorated with bladder cancer-specific ligands on the surface and loaded with the chemotherapeutic drug paclitaxel. MATERIALS & METHODS Targeting efficacy and specificity was determined with cell lines. An in vivo targeting and anti-tumor efficacy study was conducted in mice carrying patient-derived xenografts. RESULTS & DISCUSSION Targeting micelles were more efficient than nontargeting micelles in delivering the drug load into bladder cancer cells both in vitro and in vivo (p < 0.05). The micelle formulation of paclitaxel was less toxic than free paclitaxel in Cremophor(®) (Sigma, MO, USA) and allowed administration of three-times the maximum tolerated dose without increasing the toxicity. Targeting micelles were more effective than the nontargeting micelles in controlling cancer growth (p = 0.0002) and prolonging overall survival (p = 0.002). CONCLUSION Targeting micelles loaded with paclitaxel offer strong potential for clinical applications in treating bladder cancer.

Targeting canine bladder transitional cell carcinoma with a human bladder cancer-specific ligand

ObjectiveTo determine if a human bladder cancer-specific peptide named PLZ4 can target canine bladder cancer cells.Experimental DesignThe binding of PLZ4 to five established canine invasive transitional cell carcinoma (TCC) cell lines and to normal canine bladder urothelial cells was determined using the whole cell binding assay and an affinitofluorescence assay. The WST-8 assay was performed to determine whether PLZ4 affected cell viability. In vivo tumor-specific homing/targeting property and biodistribution of PLZ4 was performed in a mouse xenograft model via tail vein injection and was confirmed with ex vivo imaging.ResultsPLZ4 exhibited high affinity and specific dose-dependent binding to canine bladder TCC cell lines, but not to normal canine urothelial cells. No significant changes in cell viability or proliferation were observed upon incubation with PLZ4. The in vivo and ex vivo optical imaging study showed that, when linked with the near-infrared fluorescent dye Cy5.5, PLZ4 substantially accumulated at the canine bladder cancer foci in the mouse xenograft model as compared to the control.Conclusions and Clinical RelevancePLZ4 can specifically bind to canine bladder cancer cells. This suggests that the preclinical studies of PLZ4 as a potential diagnostic and therapeutic agent can be performed in dogs with naturally occurring bladder cancer, and that PLZ4 can possibly be developed in the management of canine bladder cancer.

Multifunctional targeting micelle nanocarriers with both imaging and therapeutic potential for bladder cancer

Background We previously developed a bladder cancer-specific ligand (PLZ4) that can specifically bind to both human and dog bladder cancer cells in vitro and in vivo. We have also developed a micelle nanocarrier drug-delivery system. Here, we assessed whether the targeting micelles decorated with PLZ4 on the surface could specifically target dog bladder cancer cells. Materials and methods Micelle-building monomers (ie, telodendrimers) were synthesized through conjugation of polyethylene glycol with a cholic acid cluster at one end and PLZ4 at the other, which then self-assembled in an aqueous solution to form micelles. Dog bladder cancer cell lines were used for in vitro and in vivo drug delivery studies. Results Compared to nontargeting micelles, targeting PLZ4 micelles (23.2 ± 8.1 nm in diameter) loaded with the imaging agent DiD and the chemotherapeutic drug paclitaxel or daunorubicin were more efficient in targeted drug delivery and more effective in cell killing in vitro. PLZ4 facilitated the uptake of micelles together with the cargo load into the target cells. We also developed an orthotopic invasive dog bladder cancer xenograft model in mice. In vivo studies with this model showed the targeting micelles were more efficient in targeted drug delivery than the free dye (14.3×; P < 0.01) and nontargeting micelles (1.5×; P < 0.05). Conclusion Targeting micelles decorated with PLZ4 can selectively target dog bladder cancer cells and potentially be developed as imaging and therapeutic agents in a clinical setting. Preclinical studies of targeting micelles can be performed in dogs with spontaneous bladder cancer before proceeding with studies using human patients.

Investigation of near-infrared autofluorescence imaging for the detection of breast cancer

Detection of breast cancer in fresh tissue obtained from surgery is investigated using near-infrared autofluorescence imaging under laser excitation at 532 and 632.8 nm. The differences in intensity between the three main components of breast tissue (cancer, fibrous, and adipose) are estimated and compared to those obtained from cross-polarized light scattering images recorded under polarized illumination at 700 nm. The optical spectroscopic images for each tissue sample were subsequently compared with the histopathology slides. The experimental results indicate that the intensity of the near-infrared emission is considerably different in breast cancer compared to that of the adjacent nonneoplastic tissues (adipose and fibrous tissue). The experimental results suggest that 632.8-nm excitation offers key advantages compared to 532 nm excitation.