Localization and phototoxic effect of zinc sulfophthalocyanine photosensitizer in human colon (DLD-1) and lung (A549) carcinoma cells (in vitro)

Photodynamic Therapy for Colorectal Cancer: An Update and a Look to the Future

This review provides an update on the current state of photodynamic therapy (PDT) for colorectal cancer (CRC) and explores potential future directions in this field. PDT has emerged as a promising minimally invasive treatment modality that utilizes photosensitizers and specific light wavelengths to induce cell death in targeted tumor tissues. In recent years, significant progress has been made in understanding the underlying mechanisms, optimizing treatment protocols, and improving the efficacy of PDT for CRC. This article highlights key advancements in PDT techniques, including novel photosensitizers, light sources, and delivery methods. Furthermore, it discusses ongoing research efforts and potential future directions, such as combination therapies and nanotechnology-based approaches. By elucidating the current landscape and providing insights into future directions, this review aims to guide researchers and clinicians in harnessing the full potential of PDT for the effective management of CRC.

Preparation of rutin-loaded mesoporous silica nanoparticles and evaluation of its physicochemical, anticancer, and antibacterial properties

BACKGROUND

The studies have shown that rutin has great potential as an anticancer and antimicrobial plant base agent; nevertheless, poor bioavailability and low aqueous solubility of rutin limit its application. One of the beneficial routes to increase the solubility and bioavailability of rutin is the development of nanoparticulate material. This study aimed to assess the anticancer and antibacterial effects of rutin-loaded mesoporous silica nanoparticles (RUT-MSNs).

METHODS

RUT-MSNs were prepared and physicochemically characterized. The cytotoxicity of RUT-MSNs on the HN5 cells as head and neck cancer cells was evaluated. The expression level of apoptosis-related genes such as Bcl-2 and Bax genes were evaluated. In addition, ROS production of RUT-MSNs treated cells was assessed. In addition, minimum inhibitory concentration (MIC), biofilm, and attachment inhibitory effects of RUT-MSNs compared with free rutin were assessed against different bacterial strains.

RESULTS

Transmission electron microscopy (TEM) showed mesoporous rod-shaped nanoparticles with an average particle size of less than 100 nm. RUT-MSNs displayed the cytotoxic effect with IC₅₀ of 20.23 µM in 48 h of incubation time (p < 0.05). The elevation in the ratio of Bax/Bcl-2 was displayed within the IC₅₀ concentration of RUT-MSNs in 48 h (p < 0.05). The antibacterial action of rutin was improved by loading rutin in MSNs to the nano-sized range in the MIC test.

CONCLUSION

The anticancer and antibacterial effects of RUT-MSNs were considerably more than rutin. RUT-MSNs inhibited the growth of HN5 cells by inducing apoptosis and producing ROS. These results suggest that RUT-MSNs may be useful in the treatment of cancers and infections.

Photodynamic Therapy Efficacy of Novel Zinc Phthalocyanine Tetra Sodium 2-Mercaptoacetate Combined with Cannabidiol on Metastatic Melanoma

This work reports for the first time on the synthesis, characterization, and photodynamic therapy effect of a novel water-soluble zinc (II) 2(3), 9(10), 16(17), 23(24)-tetrakis-(sodium 2-mercaptoacetate) phthalocyanine (ZnPcTS41), on metastatic melanoma cells (A375) combined with cannabidiol (CBD). The ZnPcTS41 structure was confirmed using FTIR, NMR, MS, and elemental analysis while the electronic absorption spectrum was studied using UV-VIS. The study reports further on the dose-dependent effects of ZnPcTS41 (1-8 µM) and CBD alone (0.3-1.1 µM) at 636 nm with 10 J/cm2 on cellular morphology and viability. The IC50 concentrations of ZnPcTS41 and CBD were found to be 5.3 µM and 0.63 µM, respectively. The cytotoxicity effects of the ZnPcTS41 enhanced with CBD on A375 cells were assessed using MTT cell viability assay, ATP cellular proliferation and inverted light microscopy. Cell death induction was also determined via Annexin V-FITC-PI. The combination of CBD- and ZnPcTS41-mediated PDT resulted in a significant reduction in cell viability (15%***) and an increase in the late apoptotic cell population (25%*). These findings suggest that enhancing PDT with anticancer agents such as CBD could possibly obliterate cancer cells and inhibit tumor recurrence.

Effect of Curcumin-Loaded Mesoporous Silica Nanoparticles on the Head and Neck Cancer Cell Line, HN5

Curcumin is an active ingredient isolated from Curcuma longa. It has several pharmacological effects, including anticancer, anti-inflammatory, and antioxidant effects. Due to its low bioavailability, chemical structure instability, and easy oxidation, the application of curcumin has been limited. In this study, to overcome these limitations, curcumin-loaded mesoporous silica nanoparticles (Cur-MSN) were prepared, and the anticancerous effect of Cur-MSNs on head and neck cancer cells, HN5, was investigated. Transmission electron microscopy (TEM) revealed rod-shaped mesoporous nanoparticles with average particle size smaller than 100 nm. Higher cytotoxicity of Cur-MSNs was seen in treated cancer cells compared with free curcumin. The expression of Bcl-2 was significantly reduced in the presence of Cur-MSNs compared to the control (untreated HN5 cells) (p < 0.05). A 3.43-fold increase in the Bax/Bcl-2 ratio was seen in Cur-MSNs treated HN5 cells at the IC50. Cur-MSNs increased intracellular reactive oxygen species (ROS) production. Based on these novel results, we suggest that Cur-MSNs offer efficacy for cancer treatment and future studies should further characterize their properties in various experimental cancer models.

In Vitro Cell Death Mechanisms Induced by Dicoma anomala Root Extract in Combination with ZnPcS4 Mediated-Photodynamic Therapy in A549 Lung Cancer Cells

Globally, lung cancer has remained the leading cause of morbidity and mortality in men and women. To enhance photodynamic therapeutic effects in vitro, the present study was designed to reduce dose-dependence in photodynamic therapy (PDT) and evaluate the anticancer effects of Dicoma anomala (D. anomala) root extracts (i.e., chloroform (Chl), ethyl acetate (EtOAc), and methanol (MeOH)) on A549 lung cancer cells. The most active extract of D. anomala (D.A) was used to establish the 50% inhibitory concentration (IC₅₀), which was further used to evaluate the anticancer efficacy of D.A in combination with ZnPcS₄-mediated PDT IC₅₀. The study further evaluated cell death mechanisms by cell viability/ cytotoxicity (LIVE/DEAD^TM assay), flow cytometry (Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) staining), immunofluorescence (p38, p53, Bax, and caspase 3 expressions), and fluorometric multiplex assay (caspase 8 and 9) 24 h post-treatment with IC₅₀ concentrations of ZnPcS₄-mediated PDT and D.A MeOH root extract. Morphological changes were accompanied by a dose-dependent increase in cytotoxicity, decrease in viability, and proliferation in all experimental models. Apoptosis is the highly favored cell death mechanism observed in combination therapy groups. Apoptotic activities were supported by an increase in the number of dead cells in the LIVE/DEAD^TM assay, and the upregulation of p38, p53, Bax, caspase 3, 8, and 9 apoptotic proteins. In vitro experiments confirmed the cytotoxic and antiproliferative effects of D.A root extracts in monotherapy and in combination with ZnPcS₄-mediated PDT. Taken together, our findings demonstrated that D.A could be a promising therapeutic candidate worth exploring in different types of cancer.

Secure transplantation by tissue purging using photodynamic therapy to eradicate malignant cells

The field of photodynamic therapy (PDT) for treating various malignant neoplasms has been given researchers' attention due to its ability to be a selective and minimally invasive cancer therapy strategy. The possibility of tumor cell infection and hence high recurrence rates in cancer patients tends to restrict autologous transplantation. So, the photodynamic tissue purging process, which consists of selective photoinactivation of the malignant cells in the graft, is defined as a compromising strategy to purify contaminated tissues before transplantation. In this strategy, the direct malignant cells' death results from the reactive oxygen species (ROS) generation through the activation of a photosensitizer (PS) by light exposure in the presence of oxygen. Since new PS generations can effectively penetrate the tissue, PDT could be an ideal ex vivo tissue purging protocol that eradicates cancer cells derived from various malignancies. The challenge is that the applied pharmacologic ex vivo tissue purging should efficiently induce tumor cells with minor influence on normal tissue cells. This review aims to provide an overview of the current status of the most effective PDT strategies and PS development concerning their potential application in ex vivo purging before hematopoietic stem cell or ovarian tissue transplantation.

Dicoma anomala Enhances Phthalocyanine Mediated Photodynamic Therapy in MCF-7 Breast Cancer Cells

Breast cancer is one of the most common types of cancer in women, and it is regarded as the second leading cause of cancer-related deaths worldwide. The present study investigated phytochemical profiling, in vitro anticancer effects of Dicoma anomala methanol root extract and its enhancing effects in phthalocyanine mediated PDT on MCF-7 (ATCC^® HTB-22™) breast cancer cells. Ultra-high performance liquid chromatography coupled to electrospray ionization quadrupole-time of flight mass spectrometry (UHPLC-qTOF-MS²) was used to identify the secondary metabolites in the crude extract. The 50% inhibitory concentration (IC₅₀) of the two experimental models was established from dose response studies 24 h post-treatment with D. anomala methanol root extract (25, 50, and 100 μg/ml) and ZnPcS₄ (5, 10, 20, 40, and 60 μM) mediated PDT. The inverted microscope was used to analyze morphological changes, trypan blue exclusion assay for viability, and Annexin V-fluorescein isothiocyanate (FITC)-propidium iodide (PI) for cell death mechanisms. Immunofluorescence analysis was used to investigate the qualitative expression of the Bax, p53, and caspase 3 apoptotic proteins. Experiments were performed 4 times (n = 4) and SPSS version 27 software was used to analyze statistical significances. D. anomala methanol root extract induced cell death in MCF-7 cells by decreasing cell viability. The combination of D. anomala methanol root extract and ZnPcS₄ mediated PDT led to a significant increase in apoptotic activities, expression of Bax, and p53 with significant decrease in cell viability. These findings pinpoint the possibility of D. anomala methanol root extract of being employed as a natural antiproliferative agent in the treatment of various cancers.

Synthesis of a novel nanobioconjugate for targeted photodynamic therapy of colon cancer enhanced with cannabidiol

Photodynamic therapy (PDT) is a promising primary treatment option for colorectal cancer (CRC), however CRC is accelerated by resilient CRC stem-like cells, which decrease its efficacy. In recent years, researchers have shown an emerging interest in the anticancer stem cell effects of cannabidiol (CBD). This study developed a targeted nanobioconjugate for specific ZnPcS4 photosensitizer intracellular accumulation within in vitro cultured human CRC cells (CaCo-2) for enhanced PDT primary treatment, as well as limited its secondary spread by combining this treatment with CBD. The final nanobioconjugate (FNBC) was successfully synthesized and characterized using various methods. The cytotoxicity of the FNBC and CBD were tested on CRC cells using laser irradiation at 673 nm with a fluency of 10 J/cm². 24 h post treatment, morphological changes were assessed via microscopy, cell viability was measured using Annexin V-FITC and cellular nuclear DNA was visualized under fluorescent microscopy, following Hoechst staining. FNBC and CBD combinative treatment induced the most significant photodamage, leaving a staggering 6%^*** viable cells. Overall, through active targeting of CRC cells using the FNBC, the enhanced PDT primary treatment of CRC was achieved, and the combinative treatment with CBD noted significant limitations on its secondary spread.

Phthalocyanine and Its Formulations: A Promising Photosensitizer for Cervical Cancer Phototherapy

Cervical cancer is one of the most common causes of cancer-related deaths in women worldwide. Despite advances in current therapies, women with advanced or recurrent disease present poor prognosis. Photodynamic therapy (PDT) has emerged as an effective therapeutic alternative to treat oncological diseases such as cervical cancer. Phthalocyanines (Pcs) are considered good photosensitizers (PS) for PDT, although most of them present high levels of aggregation and are lipophilic. Despite many investigations and encouraging results, Pcs have not been approved as PS for PDT of invasive cervical cancer yet. This review presents an overview on the pathophysiology of cervical cancer and summarizes the most recent developments on the physicochemical properties of Pcs and biological results obtained both in vitro in tumor-bearing mice and in clinical tests reported in the last five years. Current evidence indicates that Pcs have potential as pharmaceutical agents for anti-cervical cancer therapy. The authors firmly believe that Pc-based formulations could emerge as a privileged scaffold for the establishment of lead compounds for PDT against different types of cervical cancer.

Photodynamic cancer therapy using liposomes as an advanced vesicular photosensitizer delivery system

The multidisciplinary field of photodynamic therapy (PDT) is a combination of photochemistry and photophysics sciences, which has shown tremendous potential for cancer therapy application. PDT employs a photosensitizing agent (PS) and light to form cytotoxic reactive oxygen species and subsequently oxidize light-exposed tissue. Despite numerous advantages of PDT and enormous progress in this field, common PSs are still far from ideal treatment because of their poor permeability, non-specific phototoxicity, side effects, hydrophobicity, weak bioavailability, and tendency to self-aggregation. To circumvent these limitations, PS can be encapsulated in liposomes, an advanced drug delivery system that has demonstrated the ability to enhance drug permeability into biological membranes and loading both hydrophobic and lipophilic agents. Moreover, liposomes can also be coated by targeting agents to improve delivery efficiency. The present review aims to summarize the principles of PDT, various PS generations, PS-loaded nanoparticles, liposomes, and their impact on PDT, then discuss recent photodynamic cancer therapy strategies using liposomes as PS-loaded vectors, and highlight future possibilities and perspectives.

Zinc Phthalocyanine Photochemistry by Raman Imaging, Fluorescence Spectroscopy and Femtosecond Spectroscopy in Normal and Cancerous Human Colon Tissues and Single Cells

Photodynamic therapy is a clinically approved alternative method for cancer treatment in which a combination of nontoxic drugs known as photosensitizers and oxygen is used. Despite intensive investigations and encouraging results, zinc phthalocyanines (ZnPcs) have not yet been approved as photosensitizers for clinical use. Label-free Raman imaging of nonfixed and unstained normal and cancerous colon human tissues and normal human CCD18-Co and cancerous CaCo-2 cell lines, without and after adding ZnPcS4 photosensitizer, was analyzed. The biochemical composition of normal and cancerous colon tissues and colon cells without and after adding ZnPcS4 at the subcellular level was determined. Analyzing the fluorescence/Raman signals of ZnPcS4, we found that in normal human colon tissue samples, in contrast to cancerous ones, there is a lower affinity to ZnPcS4 phthalocyanine. Moreover, a higher concentration in cancerous tissue was concomitant with a blue shift of the maximum peak position specific for the photosensitizer from 691-695 nm to 689 nm. Simultaneously for both types of samples, the signal was observed in the monomer region, confirming the excellent properties of ZnPcS4 for photo therapy (PDT). For colon cell experiments with a lower concentration of ZnPcS4 photosensitizer, c = 1 × 10-6 M, the phthalocyanine was localized in mitochondria/lipid structures; for a higher concentration, c = 9 × 10-6 M, localization inside the nucleus was predominant. Based on time-resolved experiments, we found that ZnPcS4 in the presence of biological interfaces features longer excited-state lifetime photosensitizers compared to the aqueous solution and bare ZnPcS4 film on CaF2 substrate, which is beneficial for application in PDT.

Zinc(II) phthalocyanines as photosensitizers for antitumor photodynamic therapy

Photodynamic therapy (PDT) is a highly specific and clinically approved method for cancer treatment in which a nontoxic drug known as photosensitizer (PS) is administered to a patient. After selective tumor irradiation, an almost complete eradication of the tumor can be reached as a consequence of reactive oxygen species (ROS) generation, which not only damage tumor cells, but also lead to tumor-associated vasculature occlusion and the induction of an immune response. Despite exhaustive investigation and encouraging results, zinc(II) phthalocyanines (ZnPcs) have not been approved as PSs for clinical use yet. This review presents an overview on the physicochemical properties of ZnPcs and biological results obtained both in vitro and in more complex models, such as 3D cell cultures, chicken chorioallantoic membranes and tumor-bearing mice. Cell death pathways induced after PDT treatment with ZnPcs are discussed in each case. Finally, combined therapeutic strategies including ZnPcs and the currently available clinical trials are mentioned.

Genetic Aberrations Associated with Photodynamic Therapy in Colorectal Cancer Cells

Photodynamic therapy (PDT) is a cancer treatment modality that utilizes three components: light (λ 650-750 nm), a photosensitizer (PS) and molecular oxygen, which upon activation renders the modality effective. Colorectal cancer has one of the highest incident rates as well as a high mortality rate worldwide. In this study, a zinc (Zn) metal-based phthalocyanine (ZnPcSmix) PS was used to determine its efficacy for the treatment of colon adenocarcinoma cells (DLD-1 and Caco-2). Photoactivation of the PS was achieved by laser irradiation at a wavelength of 680 nm. Dose responses were performed to establish optimal PS concentration and irradiation fluence. A working combination of 20 µM ZnPcSmix and 5 J/cm² was used. Biochemical responses were determined after 1 or 24 h incubation post-treatment. Since ZnPcSmix is localized in lysosomes and mitochondria, mitochondrial destabilization analysis was performed monitoring mitochondrial membrane potential (MMP). Cytosolic acidification was determined measuring hydrogen peroxide (H₂O₂) levels in the cytoplasm. Having established apoptotic cell death induction, an apoptosis PCR array was performed to establish the apoptotic mechanism. In DLD-1 cells, expression of genes included 3 up-regulated and 20 down-regulated genes while in Caco-2 cells, there were 16 up-regulated and 22 down-regulated genes. In both cell lines, in up-regulated genes, there was a combination of pro- and anti-apoptotic genes that were significantly expressed. Gene expression results showed that more tumorigenic cells (DLD-1) went through apoptosis; however, they exhibit increased risk of resistance and recurrence, while less tumorigenic Caco-2 cells responded better to PDT, thus being suggestive of a better prognosis post-PDT treatment. In addition, the possible apoptotic mechanisms of cell death were deduced based on the genetic expression profiling of regulatory apoptotic inducing factors.

Evaluation of cell damage induced by irradiated Zinc-Phthalocyanine-gold dendrimeric nanoparticles in a breast cancer cell line

BACKGROUND

Cancer is a non-communicable disease that occurs following a mutation in the genes which control cell growth. Breast cancer is the most diagnosed cancer among South African women and a major cause of cancer-related deaths worldwide. Photodynamic therapy (PDT) is an alternative cancer therapy that uses photochemotherapeutic agents, known as photosensitizers. Drug-delivery nanoparticles are commonly used in nanomedicine to enhance drug-therapeutic efficiency. This study evaluated the photodynamic effects following treatment with 0.3 μM multiple particles delivery complex (MPDC) and irradiated with a laser fluence of 10 J/cm2 using a 680 nm diode laser in a breast cancer cell line (MCF-7).

METHODS

Cell damage was assessed by inverted light microscopy for cell morphology; the Apoptox-Glo triple assay was used for cell viability, caspase activity and identification of cytodamage markers; flow cytometric analysis for cell death pathways and mitochondrial membrane potential; the enzyme linked immunosorbent assay (ELISA) for cytochrome C release; and real-time reverse transcriptase polymerase chain reaction (RT-PCR) array for gene expression.

RESULTS

Laser activated-MPDC induced a significant change in morphology of PDT-treated cells, with the appearance of apoptotic like morphological features. An increase in cytotoxicity, caspase activity, cell depolarization and cytochrome C release were identified in PDT-treated cells. Finally, the upregulation of BAX, BCL-2, CASP-2 and ULK-1 genes was observed.

CONCLUSION

The MPDC yielded a successful and stable hybrid agent with potent photodynamic abilities.

Cervical cancer cells (HeLa) response to photodynamic therapy using a zinc phthalocyanine photosensitizer

Cervical cancer is the most common gynecological malignancy worldwide, and the leading cause of cancer related deaths among females. Conventional treatment for early cervical cancer is radical hysterectomy. In locally advanced cancer the treatment of choice is concurrent chemo radiation. Although such treatment methods show promise, they do have adverse side effects. To minimize these effects, as well as prevent cancer re-occurrence, new treatment methods are being investigated. Photodynamic therapy (PDT) involves the selective uptake of a photosensitizer (PS) by cancer cells, illumination with light of an appropriate wavelength that triggers a photochemical reaction leading to the generation of reactive oxygen and subsequent tumor regression. The effect of PDT on a cervical cancer cell line (HeLa) was assessed by exposing cultured cells to a sulphonated zinc phthalocyanine PS (ZnPcS_mix) and irradiating the cells using a 673nm diode laser. The effects were measured using the Trypan blue viability assay, adenosine triphosphate assay (ATP) luminescence assay for proliferation, Lactate Dehydrogenase (LDH) membrane integrity cytotoxicity assay, and fluorescent microscopy to assess PS cellular localization and nuclear damage. Fluorescent microscopy revealed localization of the PS in the cytoplasm and perinuclear region of HeLa cells. PDT treated cellular responses showed dose dependent structural changes, with decreased cell viability and proliferation, as well as considerable membrane damage. Hoechst stained cells also revealed DNA damage in PDT treated cells. The final findings from this study suggest that ZnPcS_mix is a promising PS for the PDT treatment of cervical cancer in vitro, where a significant 85% cellular cytotoxicity with only 25% cellular viability was noted in cells which received 1μM ZnPcS_mix when an 8J/cm² fluence was applied.

Low-Intensity Laser Irradiation at 636 nm Induces Increased Viability and Proliferation in Isolated Lung Cancer Stem Cells

OBJECTIVE

The purpose of this in vitro study was to evaluate the effects of low-intensity laser irradiation (LILI) on isolated lung cancer stem cells (CSCs) after several time intervals, using a wavelength of 636 nm and fluences between 5 and 20 J/cm².

BACKGROUND DATA

LILI has been proven to have a biomodulatory effect on various diseased conditions. A number of studies have been conducted on CSCs.

METHODS

Lung CSCs were isolated from lung cancer cells (A549), using cell surface marker CD 133. Isolated lung CSCs were divided into four groups: group 1 consisted of control cells receiving no irradiation; groups 2, 3, and 4 were exposed to laser irradiation at fluences of 5, 10, and 20 J/cm², respectively. LILI was performed using a 636 nm diode laser with a power output of ±85 mW. Cellular responses were evaluated after 24, 48, or 72 h, and included cell morphology, viability, and proliferation.

RESULTS

Cellular morphology indicated an increase in cell density caused by cell proliferation over time. Biostimulatory effects were achieved in lung CSCs when examining viability and proliferation.

CONCLUSIONS

It should, therefore, be noted that a low wavelength of 636 nm at various fluences induces biostimulation, which may have detrimental effects when using LILI as a form of regeneration.

Photodynamic therapy in colorectal cancer treatment--The state of the art in preclinical research

BACKGROUND

Photodynamic therapy (PDT) is used in many different oncologic fields. Also in gastroenterology, where have been a few attempts to treat both the premalignant lesion and advanced colorectal cancer (CRC). This review aims to give a general overview of preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment to emphasize their potential in study of PDT mechanism, safety and efficiency to translate these results into clinical benefit in CRC treatment.

MATERIALS AND METHOD

Literature on in vitro preclinical photodynamic studies related to CRC cells and animal studies of photodynamic effects related to CRC treatment with the fallowing medical subject headings search terms: colorectal cancer, photodynamic therapy, photosensitizer(s), in vitro, cell culture(s), in vivo, animal experiment(s). The articles were selected by their relevance to the topic.

RESULTS

The majority of preclinical studies concerning possibility of PDT application in colon and rectal cancer is focused on phototoxic action of photosensitizers toward cultured colorectal tumor cells in vitro. The purposes of animal experiments are usually elucidation of mechanisms of observed photodynamic effects in scale of organism, estimation of PDT safety and efficiency and translation of these results into clinical benefit.

CONCLUDING REMARKS

In vitro photodynamic studies and animal experiments can be useful for studies of mechanisms and efficiency of photodynamic method as a start point on PDT clinical research. The primary disadvantage of in vitro experiments is a risk of over-interpretation of their results during extrapolation to the entire CRC.

Cell death pathways and phthalocyanine as an efficient agent for photodynamic cancer therapy

The mechanisms of cell death can be predetermined (programmed) or not and categorized into apoptotic, autophagic and necrotic pathways. The process of Hayflick limits completes the execution of death-related mechanisms. Reactive oxygen species (ROS) are associated with oxidative stress and subsequent cytodamage by oxidizing and degrading cell components. ROS are also involved in immune responses, where they stabilize and activate both hypoxia-inducible factors and phagocytic effectors. ROS production and presence enhance cytodamage and photodynamic-induced cell death. Photodynamic cancer therapy (PDT) uses non-toxic chemotherapeutic agents, photosensitizer (PS), to initiate a light-dependent and ROS-related cell death. Phthalocyanines (PCs) are third generation and stable PSs with improved photochemical abilities. They are effective inducers of cell death in various neoplastic models. The metallated PCs localize in critical cellular organelles and are better inducers of cell death than other previous generation PSs as they favor mainly apoptotic cell death events.

Combination of a novel photosensitizer DTPP with 650 nm laser results in efficient apoptosis, arresting cell cycle and cytoskeleton protein changes in lung cancer A549 cells

Photodynamic therapy (PDT) using photosensitized reaction to produce cytotoxicity was used for cancer therapy in recent years. To study the effectiveness of PDT mediated by a novel photosensitizer (PS), DTPP 5-(4'-(2″-dicarboxymethylamino)acetamidophenyl)-10, 15, 20-triphenylporphyrin, on lung cancer A549 cell lines in vitro, DTPP was employed in different concentrations (2, 4, 6, 8, 10, 12, 15, 20, 25, and 30 μg/ml) and combined with 650 nm laser of different power densities (0.6, 1.2, 2.4, 4.8, 7.2, and 9.6 J/cm(2)) that resulted in obvious inhibition of cell proliferation and apoptosis. Results showed that cell survival rates have a dependent relationship with time and PS concentrations and no significant cytotoxicity was induced by DTPP itself. Apoptosis and cell cycle S arrest were observed; cytoskeleton morphologic observation revealed collapse, sparkling, and shrunken shapes. Apoptosis-related protein caspase-3 overexpression was detected while caspase-9, bcl-2, and cytoskeleton protein beta-catenin were in low levels of expression than the control. Cleavage of beta-catenin by caspase-3 or other proteases from the lysosome might be the main reason for the cytoskeleton collapse as beta-tubulin and actin were at a stable level 12 h after PDT. This paper gives a better understanding of the effectiveness of DTPP-mediated PDT in lung cancer A549 cells both with regard to dosimetry and apoptosis changes.

Killing effect of Ad5/F35-APE1 siRNA recombinant adenovirus in combination with hematoporphrphyrin derivative-mediated photodynamic therapy on human nonsmall cell lung cancer

The main goal of this work is to investigate the killing effects and molecular mechanism of photodynamic therapy (PDT) mediated by the Ad5/F35-APE1 siRNA recombinant adenovirus in combination with a hematoporphrphyrin derivative (HpD) in the A549 human lung adenocarcinoma cell line in vitro to provide a theoretical reference for treating lung cancer by HpD-PDT. By using the technologies of MTT, flow cytometry, ELISA, and western blot, we observed that the proliferation inhibition and apoptosis of the A549 cells were significantly higher than the control group (P < 0.05) after HpD-PDT was performed. The inhibitory efficiency is dependent on the HpD concentration and laser intensity dose. The inhibitory effect on the proliferation of A549 cells of Ad5/F35-APE1 siRNA is more significant after combining with PDT, as indicated by a significant elevation of the intracellular ROS level and the expression of inflammatory factors (P < 0.05). The HpD-PDT-induced expression of the APE1 protein reached the peak after 24 h in A549 cells. The inhibition of APE1 expression in A549 cells was most significant after 48 hours of infection by Ad5/F35-APE1 siRNA recombinant adenovirus (10 MOI). In conclusion, the Ad5/F35-APE1 siRNA recombinant adenovirus could efficiently inhibit the HpD-PDT-induced APE1 expression hence could significantly enhance the killing effect of HpD-PDT in lung cancer cells.