pheophorbide-a and Prostatic-Neoplasms

We previously reported that pheophorbide a (PhA), excited by 630 nm light, significantly inhibited the growth of prostate cancer cells. In this study, we employed whole-cell proteomics to investigate photodynamic treatment (PDT)-related proteins.. Two-dimensional gel electrophoresis (2-DE) coupled with tandem mass spectrometry was employed to reveal the proteins involved in PhA-mediated PDT in LNCaP and PC-3 prostate cancer cells.. After PhA-PDT treatment, decreased expression of translationally-controlled tumor protein (TCTP) was found in both PC-3 and LNCaP whole-cell proteomes. In contrast, human rab GDP dissociation inhibitor (GDI) in LNCaP cells and ras-related homologs GDI in PC-3 cells were up-regulated.. GDP-GTP exchange is an underlying target of photodynamic treatment in prostate cancer cells.

Topics: Cell Line, Tumor; Chlorophyll; Guanosine Diphosphate; Guanosine Triphosphate; Humans; Male; PC-3 Cells; Photochemotherapy; Photosensitizing Agents; Prostatic Neoplasms; Proteomics; ras Proteins; Tandem Mass Spectrometry; Tumor Protein, Translationally-Controlled 1; Two-Dimensional Difference Gel Electrophoresis

To observe the effects of pheophorbide a-mediated photodynamic therapy (Pa-PDT) on the in vitro proliferation, apoptosis, invasion and metastasis of human prostate cancer PC-3 cells and to investigate its possible mechanism.. Pa-PDT in gradient concentrations (0 μM, 0.25 μM, 0.5 μM, 1 μM, 2 μM, and 4 μM) were used to act on PC-3 cells; the cell proliferation in each group was detected via methyl thiazolyl tetrazolium (MTT) assay and clone formation assay, and the cell apoptosis was detected via Hochst33258 staining and Annexin V/propidium iodide (PI) double labeling. Moreover, the effects of Pa-PDT on invasion and proliferation of PC-3 cells were observed via wound healing assay and transwell chamber assay. Finally, the expressions of apoptosis-related proteins, epithelial-mesenchymal transition (EMT)-related proteins and matrix metalloproteinases (MMPs) in each group were detected after treatment by Western blotting.. MTT and clone formation assays showed that Pa-PDT could inhibit the proliferation of PC-3 cells in a dose-dependent manner. The results of apoptosis assay revealed that Pa-PDT could significantly promote the apoptosis of PC-3 cells, obviously up-regulate the expressions of pro-apoptotic proteins, such as B-cell lymphoma-2-associated X protein (BAX), Caspase-3 and poly adenosine diphosphate-ribose polymerase (PARP), and inhibit the expression of Bcl-2. Besides, the wound healing assay and Transwell chamber assay showed that Pa-PDT could inhibit the invasion and metastasis capacities of PC-3 cells, whose relevant mechanisms were related to the fact that Pa-PDT inhibited the EMT process and down-regulated the expressions of MMPs in PC-3 cells.. Pa-PDT can inhibit the proliferation and promote the apoptosis of PC-3 cells. Moreover, it can also inhibit the invasion and metastasis capacities of PC-3 cells via inhibiting the EMT process and down-regulating the expressions of MMPs.

Topics: Apoptosis; Cell Line, Tumor; Cell Proliferation; Chlorophyll; Epithelial-Mesenchymal Transition; Humans; Male; Neoplasm Metastasis; Photochemotherapy; Prostatic Neoplasms

Photodynamic therapy (PDT) has drawn considerable attention for its efficacy against certain types of cancers. It shows however limits in the case of deep cancers, favoring tumor recurrence under suboptimal conditions. More insight into the molecular mechanisms of PDT-induced cytotoxicity and cytoprotection is essential to extend and strengthen this therapeutic modality. As PDT induces iNOS/NO in both tumor and microenvironment, we examined the role of nitric oxide (NO) in cytotoxicity and cytoprotection. Our findings show that NO mediates its cellular effects by acting on the NF-κB/YY1/RKIP loop, which controls cell growth and apoptosis. The cytoprotective effect of PDT-induced NO is observed at low NO levels, which activate the pro-survival/anti-apoptotic NF-κB and YY1, while inhibiting the anti-survival/pro-apoptotic and metastasis suppressor RKIP. In contrast, high PDT-induced NO levels inhibit NF-κB and YY1 and induce RKIP, resulting in significant anti-tumor activity. These findings reveal a critical role played by NO in PDT and suggest that the use of bifunctional PDT agents composed of a photosensitizer and a NO-donor could enhance the photo-treatment effect. A successful application of NO in anticancer therapy requires control of its concentration in the target tissue. To address this issue we propose as PDT agent, a bimolecular conjugate called DR2, composed of a photosensitizer (Pheophorbide a) and a non-steroidal anti-androgen molecule capable of releasing NO under the exclusive control of light. The mechanism of action of DR2 in prostate cancer cells is reported and discussed.

Topics: Cell Line, Tumor; Cell Survival; Chlorophyll; Humans; Male; NF-kappa B; Nitric Oxide; Nitric Oxide Donors; Phosphatidylethanolamine Binding Protein; Photochemotherapy; Photosensitizing Agents; Prostatic Neoplasms; Triazenes; YY1 Transcription Factor

Photodynamic therapy (PDT) is a clinically approved treatment that causes a selective cytotoxic effect in cancer cells. In addition to the production of singlet oxygen and reactive oxygen species, PDT can induce the release of nitric oxide (NO) by up-regulating nitric oxide synthases (NOS). Since non-optimal PDT often causes tumor recurrence, understanding the molecular pathways involved in the photoprocess is a challenging task for scientists. The present study has examined the response of the PC3 human metastatic prostate cancer cell line following repeated low-dose pheophorbide a treatments, mimicking non-optimal PDT treatment. The analysis was focused on the NF-kB/YY1/RKIP circuitry as it is (i) dysregulated in cancer cells, (ii) modulated by NO and (iii) correlated with the epithelial to mesenchymal transition (EMT). We hypothesized that a repeated treatment of non-optimal PDT induces low levels of NO that lead to cell growth and EMT via the regulation of the above circuitry. The expressions of gene products involved in the circuitry and in EMT were analyzed by western blot. The findings demonstrate the cytoprotective role of NO following non-optimal PDT treatments that was corroborated by the use of L-NAME, an inhibitor of NOS.

Topics: Cell Line, Tumor; Chlorophyll; Dose-Response Relationship, Drug; Epithelial-Mesenchymal Transition; Humans; Male; Models, Biological; Nitric Oxide; Nitric Oxide Synthase Type II; Photochemotherapy; Prostatic Neoplasms; Radiation-Sensitizing Agents

Prostate cancer (PC) represents the most common type of cancer among males and is the second leading cause of cancer death in men in Western society. Current options for PC therapy remain unsatisfactory, since they often produce uncomfortable long-term side effects, such as impotence (70%) and incontinence (5-20%) even in the first stages of the disease. Light-triggered therapies, such as photodynamic therapy, have the potential to provide important advances in the treatment of localized and partially metastasized prostate cancer. We have designed a novel molecular conjugate (DR2) constituted of a photosensitizer (pheophorbide a, Pba), connected to a nonsteroidal anti-androgen molecule through a small pegylated linker. This study aims at investigating whether DR2 represents a valuable approach for PC treatment based on light-induced production of single oxygen and nitric oxide (NO) in vitro. Besides being able to efficiently bind the androgen receptor (AR), the 2-trifluoromethylnitrobenzene ring on the DR2 backbone is able to release cytotoxic NO under the exclusive control of light, thus augmenting the general photodynamic effect. Although DR2 is similarly internalized in cells expressing different levels of androgen receptor, the AR ligand prevents its efflux through the ABCG2-pump. In vitro phototoxicity experiments demonstrated the ability of DR2 to kill cancer cells more efficiently than Pba, while no dark toxicity was observed. Overall, the presented approach is very promising for further development of AR-photosensitizer conjugates in the multimodal photodynamic treatment of prostate cancer.

Topics: Androgen Antagonists; Antineoplastic Agents; Chlorophyll; Humans; In Vitro Techniques; Male; Photochemotherapy; Photosensitizing Agents; Prostatic Neoplasms; Receptors, Androgen; Tumor Cells, Cultured