The mechanism of 5-aminolevulinic acid photodynamic therapy in promoting endoplasmic reticulum stress in the treatment of HR-HPV-infected HeLa cells

Enhancing 5-ALA-PDT efficacy against resistant tumor cells: Strategies and advances

As a precursor of protoporphyrin IX (PpIX), an endogenous pro-apoptotic and fluorescent molecule, 5-Aminolevulinic acid (5-ALA) has gained substantial attention for its potential in fluorescence-guided surgery as well as photodynamic therapy (PDT). Moreover, 5-ALA-PDT has been suggested as a promising chemo-radio sensitization therapy for various cancers. However, insufficient 5-ALA-induced PpIX fluorescence and the induction of multiple resistance mechanisms may hinder the 5-ALA-PDT clinical outcome. Reduced efficacy and resistance to 5-ALA-PDT can result from genomic alterations, tumor heterogeneity, hypoxia, activation of pathways related to cell surveillance, production of nitric oxide, and most importantly, deregulated 5-ALA transporter proteins and heme biosynthesis enzymes. Understanding the resistance regulatory mechanisms of 5-ALA-PDT may allow the development of effective personalized cancer therapy. Here, we described the mechanisms underlying resistance to 5-ALA-PTD across various tumor types and explored potential strategies to overcome this resistance. Furthermore, we discussed future approaches that may enhance the efficacy of treatments using 5-ALA-PDT.

Comparative study of treatment efficacy in severe intraepithelial squamous cell lesions and preinvasive cervical cancer by conization and chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy

BACKGROUND

Cervical cancer (CC) occupies a leading position in incidence among young women of reproductive age. In this connection, it is urgent to search for the most effective approaches to the diagnosis and treatment of this pathology. The purpose of the study was to evaluate the effectiveness of the PDT method using Cе6 with the control of the photobleaching using video and spectral fluorescence diagnostic methods, to develop the method of fluorescence-assisted systemic photodynamic therapy mediated with chlorin e6 for treatment CIN 3 and CIS.

MATERIALS AND METHODS

A randomized comparative clinical study was conducted involving 94 women aged 18 to 49 years with histologically verified severe intraepithelial squamous cell lesions of the cervix or preinvasive cervical cancer. The patients were included in 2 groups: in the first group conization of the cervix was performed with curettage of the remaining part of the cervical canal; patients in the second group underwent the chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy.

RESULTS

The absolute majority of patients in the main group after the first course of chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy showed normalization of cytological parameters and colposcopic picture, while women from the comparison group showed signs of cervical lesions statistically significantly more often. These changes corresponded to the dynamics of the proliferation markers expression in the cells of intraepithelial squamous cell lesions. Also, patients of the second group who were planning a pregnancy had better reproductive outcomes after treatment compared to those of the first group.

CONCLUSION

In general, higher clinical efficacy and safety of the use of the chlorin e6-mediated fluorescence-assisted systemic photodynamic therapy in the treatment of intraepithelial squamous cell lesions and preinvasive cervical cancer have been established compared to the use of standard treatment methods.

Nanoparticles drug delivery for 5-aminolevulinic acid (5-ALA) in photodynamic therapy (PDT) for multiple cancer treatment: a critical review on biosynthesis, detection, and therapeutic applications

Photodynamic therapy (PDT) is a promising cancer treatment that kills cancer cells selectively by stimulating reactive oxygen species generation with photosensitizers exposed to specific light wavelengths. 5-aminolevulinic acid (5-ALA) is a widely used photosensitizer. However, its limited tumour penetration and targeting reduce its therapeutic efficacy. Scholars have investigated nano-delivery techniques to improve 5-ALA administration and efficacy in PDT. This review summarises recent advances in biological host biosynthetic pathways and regulatory mechanisms for 5-ALA production. The review also highlights the potential therapeutic efficacy of various 5-ALA nano-delivery modalities, such as nanoparticles, liposomes, and gels, in treating various cancers. Although promising, 5-ALA nano-delivery methods face challenges that could impair targeting and efficacy. To determine their safety and biocompatibility, extensive preclinical and clinical studies are required. This study highlights the potential of 5-ALA-NDSs to improve PDT for cancer treatment, as well as the need for additional research to overcome barriers and improve medical outcomes.

A novel PDT: 5-aminolevulinic acid combined 450 nm blue laser photodynamic therapy significantly promotes cell death of HR-HPV infected cells

Human papillomavirus (HPV) infection and related diseases are clinical challenges. The efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) using red laser (630 ± 5 nm) is remarkable and safe. In this study, we aim to investigate the efficacy of ALA-450 nm PDT comparing with ALA-635 nm PDT. We detected cell proliferation and cell apoptosis through MTT assay and flow cytometry assay respectively. Flow cytometry assay determined the intracellular reactive oxygen species (ROS) generation. Western blotting analysis investigated the protein expression. In vivo, immunohistochemical staining assay and TUNEL assay were performer to detect cell apoptosis. ALA-450 nm PDT inhibited the proliferation of End1 and HeLa cells, promoted cell apoptosis more effectively than ALA-635 nm PDT, and induced cell death probably through increasing the intracellular ROS generation and caspase-dependent apoptosis pathway. In vivo, ALA-450 nm PDT significantly inhibited tumour growth and activated cell apoptosis. The ALA-450 nm PDT had an advantage over ALA-635 nm PDT on inhibiting the proliferation of End1 and HeLa cells and inducing cell apoptosis. The ALA-450 nm PDT might be a promising therapeutic strategy for eradicating the HR-HPV infected cells and promoting the integration of diagnosis and treatment of HR-HPV related diseases.HighlightsWe combined 5-aminolevulinic acid with 450 nm blue laser using as a novel type of photodynamic therapy.The ALA-450 nm PDT had an advantage over ALA-635 nm PDT on inhibition of the proliferation of End1 and HeLa cells and inducing cell apoptosis in vitro and in vivo.The ALA-450 nm PDT may provide a novel alternative therapeutic option in patients with persistent HPV infection and promote the integration of diagnosis and treatment.

Synthesis of novel zinc porphyrins with bioisosteric replacement of Sorafenib: Efficient theranostic agents for anti-cancer application

Novel zinc porphyrins (trans-A2B2 and A3B type) are reported containing pharmacophoric groups derived from Sorafenib at the meso-positions. The pharmacophoric and bioisosteric modification of Sorafenib was done with 2-methyl-4-nitro-N-phenylaniline. The in-vitro photo-cytotoxicity studies of zinc porphyrins on HeLa cells revealed excellent PDT based autophagy inhibition of cancer cells, with IC50 values between 6.2 to 15.4 μM. The trans-A2B2 type zinc porphyrin with two bioisosteric groups gave better cytotoxicity than A3B type. Molecular docking studies revealed excellent binding with mTOR protein kinase of the designed porphyrins. The confocal studies indicated significant ER localization of trans-A2B2 type zinc porphyrin in HeLa cells along with ROS generation. trans-A2B2 type zinc porphyrin induced ER stress in cancer cells, thereby causing elevation of Ca+2 ions in cytoplasm, which led to cancer cell death via autophagy pathway. The studies suggested that trans-A2B2 and A3B type zinc porphyrins can be developed as theranostic agents for anti-cancer applications.

Effect of topical 5-aminolevulinic acid photodynamic therapy versus therapy combined with CO2 laser pretreatment for patients with cervical high-grade squamous intraepithelial lesions

OBJECTIVE

To evaluate the effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) combined with CO2 laser pretreatment (Laser+ALA-PDT) on patients with cervical high-grade squamous intraepithelial lesions (HSILs).

METHODS

A total of 114 patients treated by ALA-PDT or Laser+ALA-PDT at 3 centers were retrospectively reviewed. The effective rate, cure rate of lesions as well as high-risk human papillomavirus (HR-HPV) regression rate and persistent infection rate in the 2 groups were compared according to 3-6 month and 9-12 months follow-ups. The characteristics and risk factors for ineffective cases were evaluated by regression analysis.

RESULTS

At the 3-6month follow-up, the effective rate was significantly higher in the Laser+ALA-PDT group than in the ALA-PDT group (96.6% vs. 81.3%, p = 0.048). A total of 79.3% of the laser+ALA-PDT patients achieved cure rate compared with 61.3% of the ALA-PDT patients (p = 0.082). In the Laser+ALA-PDT group, the HR-HPV-negative rate was significantly higher (72.4% vs. 50.7%, p = 0.045), while the persistence rate was significantly lower (20.7% vs. 42.7%, p = 0.037). At the 9-12month follow-up, the cure rate was 83% in the ALA-PDT group, 17% lower than that in the Laser+ALA-PDT group (p = 0.055). A total of 20.8% of patients in the ALA-PDT group and 5.3% in the Laser+ALA-PDT group showed persistent HR-HPV infection (p = 0.120). Pretreatment HR-HPV type, multiple infections and treatment modality were relevant factors for PDT outcome.

CONCLUSIONS

For patients with cervical HSIL, laser+ALA-PDT shows better efficiency and HPV regression compared with ALA-PDT. HPV16/18 and multi-infection may be risk factors for ineffective treatment with ALA-PDT.

Structure and functions of Aggregation-Induced Emission-Photosensitizers in anticancer and antimicrobial theranostics

Photosensitizers with Aggregation-Induced Emission (AIE) can allow the efficient light-mediated generation of Reactive Oxygen Species (ROS) based on their complex molecular structure, while interacting with living cells. They achieve better tissue targeting and allow penetration of different wavelengths of Ultraviolet-Visible-Infrared irradiation. Not surprisingly, they are useful for fluorescence image-guided Photodynamic Therapy (PDT) against cancers of diverse origin. AIE-photosensitizers can also function as broad spectrum antimicrobials, capable of destroying the outer wall of microbes such as bacteria or fungi without the issues of drug resistance, and can also bind to viruses and deactivate them. Often, they exhibit poor solubility and cellular toxicity, which compromise their theranostic efficacy. This could be circumvented by using suitable nanomaterials for improved biological compatibility and cellular targeting. Such dual-function AIE-photosensitizers nanoparticles show unparalleled precision for image-guided detection of tumors as well as generation of ROS for targeted PDT in living systems, even while using low power visible light. In short, the development of AIE-photosensitizer nanoparticles could be a better solution for light-mediated destruction of unwanted eukaryotic cells and selective elimination of prokaryotic pathogens, although, there is a dearth of pre-clinical and clinical data in the literature.

The Effect of 5-Aminolevulinic Acid Photodynamic Therapy in Promoting Pyroptosis of HPV-Infected Cells

5-aminolevulinic acid photodynamic therapy (ALA-PDT) is highly effective in the treatment of condyloma acuminata (CA). Previous research has indicated that ALA-PDT could induce cell death by different mechanisms, including apoptosis and autophagy, but the role of pyroptosis in ALA-PDT remains uncertain. Thus, this study aimed to explore whether pyroptosis is a potential mechanism of ALA-PDT killing human papillomavirus (HPV) infected cells. HPV-positive HeLa cells were exposed to ALA-PDT, then cell viability assay, lactate dehydrogenase release (LDH) assay, detection of reactive oxygen species (ROS), quantitative real-time PCR (qPCR), and western blot were used to evaluate pyroptosis induced by ALA-PDT. Results suggested that ALA-PDT enhanced the expression of NLRP3, caspase-1, GSDMD, and the production of inflammatory cytokines such as IL-1β and IL-18. In addition, ALA-PDT induced the production of ROS and led to the destruction of the cell membrane. The inhibition of pyroptosis reduced the killing of HeLa cells by ALA-PDT. This study demonstrates that ALA-PDT induces pyroptosis in HPV-positive cells, which provides some explanation for the mechanism of ALA-PDT to treat CA and HPV infection-related diseases.

Effects of Curcumin-mediated photodynamic therapy on autophagy and Epithelial-mesenchymal transition of lung cancer cells

BACKGROUND

This study aimed to investigated whether Curcumin-mediated PDT suppress EMT in lung cancer cells, and explore the roles of autophagy in the process of regulating EMT.

METHODS

Lung cancer cell viability was assessed by CCK-8 assay. The expression of epithelial marker and mesenchymal markers, the conversion of LC3-I to LC3-II and the levels of p62 and beclin1 in A549 and SPCA1 cells were measured by Western blotting assay. The Wound healing and Transwell assays were used to detect the migration and invasion abilities of the A549 and SPCA1 cells. Autophagosome formation was detected via observing the colocalization of Lamp-2 with LC3 in A549 cells, and the autophagy ultrastructure was observed by TEM.

RESULTS

Curcumin-PDT inhibited EMT, migration and invasion and induced autophagy in lung cancer cells. Curcumin-PDT induced autophagy was involved in the process of PDT inhibiting EMT, but it presented a promoting effect of EMT in lung cancer cells. Curcumin-PDT combined with CQ further inhibited EMT, invasion and migration of lung cancer cells.

CONCLUSIONS

The role of PDT-induced autophagy in the regulation of EMT was determined to be a promoting effect in lung cancer. Therefore, Curcumin-mediated PDT combined with autophagy inhibitor further suppressed EMT of lung cancer cells, and may represent a potential strategy against invasion and migration of lung cancer.

Photodynamic therapy for precancer diseases and cervical cancer (review of literature)

The paper presents the results of literature data analysis on the main directions of precancerous diseases of the cervix uteri and cervical cancer treatment. Side effects following surgery or radiation treatment can lead to structural deformities, scarring, hyperpigmentation, systemic side effects, and destruction of normal tissue. In addition, the use of traditional methods of treatment can cause multidrug resistance, which will lead to ineffective treatment and the development of a relapse of the disease. To avoid toxicity and reduce side effects, alternative treatment strategies have been proposed. Photodynamic therapy (PDT) is a promising organ-preserving highly selective method for treating cervical neoplasia, which includes two stages: the introduction of a photosensitizer and local exposure to directed light radiation. A number of studies have demonstrated the high clinical efficacy of this method in the treatment of patients with cervical neoplasia and carriage of human papillomavirus infection without adverse consequences for fertility. The use of PDT contributes to the successful outcome of the treatment of pathological foci on the mucous membrane of the cervix, the effectiveness and safety of the method is ensured by the selective effect on tissues. In the course of treatment, normal surrounding tissues are not damaged, there is no gross scarring and stenosis of the cervical canal, thereby PDT allows maintaining the normal anatomical and functional characteristics of the cervix.

Mechanism of a new photosensitizer (TBZPy) in the treatment of high-risk human papillomavirus-related diseases

BACKGROUND

High-risk human papillomavirus infection is closely related to the development of several diseases, including cervical cancer and condyloma acuminatum. We recently designed a new photosensitizer, 1-triphenylaminebenzo[c][1,2,5]thiadiazole-4-yl)styryl)-1-methylpyridin-1-ium iodide salt (TBZPy), which shows good photodynamic properties. In this study, we explored the mechanism of action of the TBZPy photosensitizer and its potential application in the treatment of high-risk human papillomavirus-related diseases.

METHODS

HeLa cells (infected by the high-risk human papillomavirus strain HPV18) were treated with TBZPy-photodynamic therapy (PDT). Cell viability, production of reactive oxygen species, apoptosis, and mitochondrial membrane depolarization were evaluated using cell counting kit-8, immunofluorescence, and flow cytometry assays, respectively. Expression levels of the anti-apoptotic proteins Bcl-2 and Bcl-X_L; pro-apoptotic proteins Bax, cytochrome C, cleaved caspase 3, and cleaved caspase 9; and the mitochondrial stress protein heat shock protein 60 were examined by western blotting.

RESULTS

TBZPy-PDT inhibited the viability and promoted reactive oxygen species production, lactate dehydrogenase release, and apoptosis of HeLa cells in vitro. TBZPy-PDT also promoted the loss of mitochondrial membrane potential, downregulated the expression of anti-apoptotic proteins, and upregulated the expression of pro-apoptotic proteins. Moreover, TBZPy-PDT downregulated the expression of the human papillomavirus E6 and E7 proteins.

CONCLUSION

Our study demonstrates the effectiveness of TBZPy-PDT against human papillomavirus-related diseases. These findings provide a foundation for using this novel photosensitizer to treat diseases associated with high-risk human papillomavirus infection.

Patterns of multiple human papillomavirus clearance during 5-aminolevulinic acid-based photodynamic therapy in patients with genital warts

BACKGROUND

Multiple human papillomavirus infections are commonly encountered in genital warts. Infection can be eliminated using 5-aminolevulinic acid-based photodynamic therapy. The aim of this study was to identify the preponderant genotypes and patterns of human papillomavirus co-infection clearance during photodynamic therapy in patients with genital warts.

METHODS

We conducted a retrospective study between January 2020 and February 2021 at two hospitals in Guangzhou, China. Human papillomavirus typing and quantitative detection were performed before starting treatment and after each session of photodynamic therapy.

RESULTS

A total of 97 patients participated in the study. Co-infections with low-risk and high-risk types were common in genital warts. Types 6 was the most common type detected, followed by types 52, 11, 58, 51 and 56. Patients with multiple infections were more likely to have high-risk human papillomavirus infection. The viral load of high-risk human papillomavirus before treatment was significantly lower than that of low-risk human papillomavirus, and decreased faster during therapy. In addition, high-risk types were cleared more readily than low-risk types, and 51.4% of high-risk types were eliminated after three rounds of therapy. A transient increase in viral load, especially low-risk types, was observed after two sessions of therapy.

CONCLUSIONS

Low-risk human papillomavirus was preponderant in patients co-infected with low-risk and high-risk types. Photodynamic therapy effectively eliminated multiple human papillomavirus infections. The response to photodynamic therapy was mainly determined by the low-risk types in patients infected with combinations of low-risk and high-risk types.