Modified 5-aminolevulinic acid photodynamic therapy reduces pain and improves therapeutic effects in cutaneous squamous cell carcinoma mouse model

PD-L1 Inhibitor Cosibelimab for Cutaneous Squamous Cell Carcinoma: Comprehensive Evaluation of Efficacy, Mechanism, and Clinical Trial Insights

Cutaneous squamous cell carcinoma (CSCC) is one of the most common non-melanoma skin cancers, and particularly challenging to treat in advanced or metastatic stages. Traditional therapies, including chemotherapy and radiation, often result in limited efficacy and severe side effects. Cosibelimab, a fully human monoclonal antibody targeting PD-L1, has emerged as a promising immunotherapy for advanced CSCC. In this review, we evaluate the therapeutic potential of cosibelimab by analyzing its mechanism of action, clinical trial data, and its role compared to other PD-1/PD-L1 inhibitors, such as pembrolizumab and cemiplimab. We synthesized the available preclinical and clinical data on cosibelimab, focusing on published Phase I and II trial results involving 76 patients. Objective response rates (ORRs), progression-free survival (PFS), overall survival (OS), and safety profiles were compared between cosibelimab, pembrolizumab, and cemiplimab. Mechanistic insights into cosibelimab's dual action, including PD-L1 blockade and antibody-dependent cellular cytotoxicity (ADCC), were also explored. Phase II trials demonstrated an ORR of 47.5%, with a median PFS of 12.9 months in advanced CSCC patients. Cosibelimab demonstrated a favorable safety profile, with predominantly mild to moderate adverse events. Comparative analysis with pembrolizumab and cemiplimab showed similar efficacy, although long-term survival data for cosibelimab is still emerging. Given its efficacy and safety, cosibelimab holds promise not only as a monotherapy but also for future exploration in combination regimens and broader oncologic indications. Future trials are required to validate its long-term outcomes, including overall survival, and to explore its use in combination therapies and neoadjuvant/adjuvant settings.

In situ pain relief during photodynamic therapy by ROS-responsive nanomicelle through blocking VGSC

Pain in photodynamic therapy (PDT), resulting from the stimulation of reactive oxygen species (ROS) and local acute inflammation, is a primary side effect of PDT that often leads to treatment interruption or termination, significantly compromising the efficacy of PDT and posing an enduring challenge for clinical practice. Herein, a ROS-responsive nanomicelle, poly(ethylene glycol)-b-poly(propylene sulphide) (PEG-PPS) encapsulated Ce6 and Lidocaine (LC), (ESCL) was used to address these problems. The tumor preferentially accumulated micelles could realize enhanced PDT effect, as well as in situ quickly release LC due to its ROS generation ability after light irradiation, which owes to the ROS-responsive property of PSS. In addition, PSS can suppress inflammatory pain which is one of the mechanisms of PDT induced pain. High LC-loaded efficiency (94.56 %) owing to the presence of the thioether bond of the PPS made an additional pain relief by inhibiting excessive inflammation besides blocking voltage-gated sodium channels (VGSC). Moreover, the anti-angiogenic effect of LC offers further therapeutic effects of PDT. The in vitro and in vivo anti-tumor results revealed significant PDT efficacy. The signals of the sciatic nerve in mice were measured by electrophysiological study to evaluate the pain relief, results showed that the relative integral area of neural signals in ESCL-treated mice decreased by 49.90 % compared to the micelles without loaded LC. Therefore, our study not only develops a very simple but effective tumor treatment PDT and in situ pain relief strategy during PDT, but also provides a quantitative pain evaluation method.

Applications and challenges of photodynamic therapy in the treatment of skin malignancies

Photodynamic Therapy (PDT), as a minimally invasive treatment method, has demonstrated its distinct advantages in the management of skin malignant tumors. This article examines the current application status of PDT, assesses its successful cases and challenges in clinical treatment, and anticipates its future development trends. PDT utilizes photosensitizers to interact with light of specific wavelengths to generate reactive oxygen species that selectively eradicate cancer cells. Despite PDT's exceptional performance in enhancing patients' quality of life and prognosis, the limitation of treatment depth and the side effects of photosensitizers remain unresolved issues. With the advancement of novel photosensitizers and innovative treatment technology, the application prospects of PDT are increasingly expansive. This article delves into the mechanism of PDT, its application in various skin malignancies, its advantages and limitations, and envisions its future development. We believe that through continuous technological enhancements and integration with other treatment technologies, PDT has the potential to assume a more pivotal role in the treatment of skin malignancies.

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.

A novel H‑tert immortalized human sebaceous gland cell line (XL-i-20) for the investigation of photodynamic therapy

BACKGROUND

Acne vulgaris is a species-specific human disease. To date, there has been no established human sebocyte cell line of Asian origin. Our previous study has demonstrated the efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of acne vulgaris, primarily attributed to its cytotoxic properties; however, its regulatory mechanism remains largely unknown.

OBJECTIVES

To establish an immortalized human sebocyte cell line derived from Chinese population and investigate the underlying mechanism of ALA-PDT.

METHODS

Human primary sebocytes were transfected with the human tert gene (h‑tert). The biological characteristics, including cell proliferation, cell markers, and sebum secretion function, were compared between primary sebocytes and the immortalized sebocytes (XL-i-20). Stimulations such as ALA-PDT, were applied respectively to both primary sebocytes and XL-i-20 cells to assess changes in their cellular functions. The transcriptome differences between primary sebocytes and XL-i-20 sebocytes were investigated using RNA-seq analysis. The XL-i-20 cell line was used to establish a sebaceous gland (SG) organoid culture, serving as a representative model of SG for the investigation of ALA-PDT.

RESULTS

The h‑tert immortalized sebocyte cell line exhibited the ability to be consecutively cultured for more than fifty passages. Both primary and immortalized cells expressed sebocyte markers such as epithelial membrane antigens (EMA, or MUC-1), Cytokeratin 7 (CK7) and adipose differentiation-related protein associated antigens (ADRP), and maintained sebum secretion function. The proliferative capacity of XL-i-20 was found to be significantly higher than that of primary sebocytes. The responses of XL-i-20 to ALA-PDT were indistinguishable from those elicited by primary sebocytes. Cell viability and sebum secretion were decreased after ALA-PDT in both two cell lines, and lipid-related proteins (SREBP-1/PPARγ) were down-regulated. The transcriptome data consistently demonstrated upregulation of genes related to inflammatory responses and downregulation of genes involved in lipid metabolism in both cell types following PDT. The analysis of common differential genes of primary sebocytes and XL-i-20 sebocytes post ALA-PDT showed that TNF signaling pathways, MAPK signaling pathways and JAK-STAT signaling pathways were activated. The SG organoids were spherical, which expressed markers of FANS and PLET1. Ki-67 was down-regulated after ALA-PDT.

CONCLUSIONS

We have developed an h‑tert immortalized sebocyte cell line from an Asian population. The cell line, XL-i-20, maintains the essential characteristics of its parent primary sebocytes. Moreover, XL-i-20 sebocyte exhibited a significant respond to ALA-PDT, demonstrating comparable phenotypic and molecular changes to primary sebocytes. Therefore, XL-i-20 and its derived SG organoid serve as appropriate in vitro models for investigating the efficacy and mechanisms of ALA-PDT in SG-related diseases.

Blue light aminolevulinic acid photodynamic therapy downregulates cell division and proliferation pathways in cutaneous squamous cell carcinoma

5-Aminolevulinic acid (5-ALA) photodynamic therapy (PDT) is a treatment for actinic keratosis (AK) and has been studied as a treatment for noninvasive cutaneous squamous cell carcinoma (cSCC). PDT induces apoptosis and necrosis in AKs and cSCC. 5-ALA blue light PDT may modulate gene expression and pathways in surviving cells. In this study, differential gene expression and pathway analysis of cSCC and human dermal fibroblasts were compared before and after 5-ALA blue light PDT using RNA sequencing. No genes were differentially expressed after correcting for multiple testing (false discovery rate < 0.05). As a result, transcription factor, gene enrichment, and pathway analysis were performed with genes identified before multiple testing (p < 0.05). Pathways associated with proliferation and carcinogenesis were downregulated. These findings using 5-ALA blue light PDT are similar to previously published studies using methyl-aminolevulinic and red light protocols, indicating that surviving residual cells may undergo changes consistent with a less aggressive cancerous phenotype.

On the Possibility of Using 5-Aminolevulinic Acid in the Light-Induced Destruction of Microorganisms

Antimicrobial photodynamic inactivation (aPDI) is a method that specifically kills target cells by combining a photosensitizer and irradiation with light at the appropriate wavelength. The natural amino acid, 5-aminolevulinic acid (5-ALA), is the precursor of endogenous porphyrins in the heme biosynthesis pathway. This review summarizes the recent progress in understanding the biosynthetic pathways and regulatory mechanisms of 5-ALA synthesis in biological hosts. The effectiveness of 5-ALA-aPDI in destroying various groups of pathogens (viruses, fungi, yeasts, parasites) was presented, but greater attention was focused on the antibacterial activity of this technique. Finally, the clinical applications of 5-ALA in therapies using 5-ALA and visible light (treatment of ulcers and disinfection of dental canals) were described.

Modified 5-aminolevulinic acid photodynamic therapy induces cutaneous squamous cell carcinoma cell pyroptosis via the JNK signaling pathway

Modified 5-aminolevulinic acid photodynamic therapy (M-PDT) is a novel therapeutic modality for cutaneous squamous cell carcinoma (cSCC) that is reported to be effective and well tolerated. However, the mechanisms underlying its antitumor effects are not fully understood. In this research, we investigated the effects of M-PDT on pyroptosis, a form of programmed cell death characterized by cell swelling, ruptures of cell membrane, and inflammatory cytokine release, in two human cSCC cell lines, SCL-1 and HSC-5. We found that M-PDT triggered pyroptosis in a dose-dependent manner, as evidenced by increased lactate dehydrogenase release, propidium iodide staining, and expression of pyroptosis-related proteins, such as NLR family pyrin domain containing 3 (NLRP3), N-terminal of gasdermin D (N-GSDMD), cleaved caspase-1, and mature interleukin 1 beta (IL-1B) in both cell lines. This process was inhibited by treatment with MCC950, an NLRP3-specific inhibitor, suggesting the involvement of the NLRP3 inflammasome in M-PDT-induced pyroptosis. We also demonstrated that M-PDT activated c-Jun N-terminal kinase (JNK) signaling, which is required for pyroptosis induction, as treatment with SP600125, a JNK inhibitor, suppressed the expression of pyroptosis-related proteins after M-PDT. JNK activation enhanced M-PDT-induced pyroptosis, highlighting the significance of the JNK pathway in M-PDT. Moreover, M-PDT increased intracellular reactive oxygen species (ROS) levels, which are responsible for JNK activation and pyroptosis induction. In summary, our results revealed that M-PDT triggers pyroptosis through ROS-mediated JNK activation and subsequent NLRP3 inflammasome activation in cSCC cells, providing a better understanding of the molecular mechanism of M-PDT and promoting its clinical application.

Modified painless photodynamic therapy for facial multiple actinic keratosis in China: A prospective split-face control study

BACKGROUND

Aminolevulinic acid photodynamic therapy (ALA-PDT) is an effective treatment for multiple actinic keratosis (AK). However, PDT-induced pain often discontinues the therapy to reduce its efficacy, limiting its application. If modified painless PDT schedule with shorter photosensitizer dressing and higher dose illumination could achieve good efficacy in AK, it is still unknown.

OBJECTIVES

To explore the efficacy and pain tolerance of the modified painless PDT (M-PDT) in facial multiple AK.

METHODS

A split-face controlled clinical study including 14 patients with facial multiple AK was conducted. The patients received conventional PDT (C-PDT) on the left and M-PDT in the contralateral area. The left area (C-PDT) was illuminated by a red light-emitting diode light (144 J/cm2 ) after applying the 10% ALA cream for 3 h; the other had illumination for a total light dose of 288 J/cm2 after applying the 10% ALA cream for 0.5 h. The primary endpoint was the lesion clearance rate at 1-month postthree sessions of PDT. Secondary endpoints included pain scores, the incidence of adverse events during treatment, and cosmetic outcomes.

RESULTS

At 1 month following three treatments, the total lesion clearance rate was comparable between M-PDT and C-PDT (91.6% vs. 89.0%). While the lesion clearance rate of M-PDT was higher than that of C-PDT in the Grade III lesions (86.5% vs. 72.0%, respectively) (p < 0.05). M-PDT achieved a 100% lesion clearance rate for Grade I lesions earlier than C-PDT, with M-PDT treated twice and C-PDT treated thrice. Moreover, the pain score during illumination was significantly lower for M-PDT than for C-PDT (p < 0.01). Regarding photoaging, the Global Subjective Skin Aging Assessment score showed that the total and atrophy scores of C-PDT and M-PDT were significantly improved, and M-PDT also reduced discoloration. There was no significant difference in adverse reactions between C-PDT and M-PDT.

CONCLUSIONS

M-PDT is comparable to C-PDT's efficacy for treating facial multiple AK, resulting in much lower pain scores.

Non-Surgical Therapeutic Strategies for Non-Melanoma Skin Cancers

OPINION STATEMENT

Non-melanoma skin cancer (NMSC) is a globally prevalent skin disease, with basal cell carcinoma and squamous cell carcinoma accounting for 99% of NMSC cases. While surgical excision is the most common approach, numerous non-surgical therapies have rapidly advanced in recent years. In cases of low-risk NMSC, alongside surgical excision, priority should be given to physical therapy and photodynamic therapy. Physical therapy modalities, exemplified by electrodessication and curettage, emerge as safe and efficacious alternatives. In juxtaposition, photodynamic therapy, albeit relatively more costly, assumes preference for patients exhibiting heightened cosmetic concerns owing to the scarring risks inherent to physical therapy and surgical excision. Notably, the combination of curettage and photodynamic therapy has exhibited remarkable efficacy in the treatment of nodular basal cell carcinoma. Additionally, for elderly patients who may be intolerant to stimulation, modified photodynamic therapy offers an almost painless option. When surgery is unavoidable, photodynamic therapy can be a valuable adjunct, allowing for a more conservative surgical approach, either before or after the procedure. Radiotherapy holds a prominent role in comprehensive treatment strategies, especially for patients ineligible for surgical intervention or those with lesions precluding further surgical measures. In cases of NMSC exhibiting perineural invasion or lymphovascular involvement, adjunctive radiotherapy is advised; however, potential adverse effects necessitate careful consideration. For advanced NMSC cases where surgery and physical therapy fall short, immunotherapy provide viable solutions. Systemic therapy employing Hedgehog pathway inhibitors can be considered for patients with distant metastatic basal cell carcinoma, despite its low incidence, or individuals with locally advanced lesions who are not surgical candidates, or those encountering recurrences after resection and radiotherapy. However, close monitoring of disease progression and adverse reactions is crucial. In this evolving landscape of NMSC treatment, personalized and multidisciplinary approaches are key, ensuring optimal outcomes while prioritizing patient safety and satisfaction.

Successful treatment of non-melanoma skin cancer in three patients with Xeroderma Pigmentosum by modified ALA-PDT

Xeroderma pigmentosum(XP) is a rare autosomal recessive genodermatosis. Individuals with XP are characterized by severe skin sensitivity to sunlight, and more susceptible to the development of skin malignancies in sun-exposed regions. We report the experience of modified 5-aminolaevulinic acid photodynamic therapy (M-PDT) in the treatment of three children with XP. They all developed multiple freckle-like hyperpigmented papules and plaques on the face from an early age. Multiple cutaneous squamous cell carcinoma (cSCC) and actinic keratosis (AK) were developed in case 1 and case 2, and basal cell carcinoma (BCC) was observed in case 3. Sanger sequencing of targeted gene identified that case 1 and case 3 carried compound heterozygous mutations, and case 2 carried a homozygous mutation in the XPC gene. After multiple courses of M-PDT, the lesions were removed with mild adverse reactions, nearly painless and satisfactory safety.

Modified 5-aminolevulinic acid photodynamic therapy suppresses cutaneous squamous cell carcinoma through blocking Akt/mTOR-mediated autophagic flux

Background: We previously found that modified 5-aminolevulinic acid photodynamic therapy (M-PDT) is painless and effective in cutaneous squamous cell carcinoma (cSCC) treatment, however, the regulatory mechanism of M-PDT in cSCC is still unclear.

Objective: To clarify the effect and relevant regulatory mechanism of M-PDT in cSCC.

Methods: The cSCC apoptosis was examined by flow cytometry, TUNEL staining and Cleaved-caspase-3 immunofluorescence, respectively. The autophagy-related characterization was detected by monodansylcadaverine (MDC) staining, transmission electron microscopy (TEM), GFP-LC3B autophagic vacuoles localization and mRFP-EGFP tandem fluorescence-tagged LC3B construct, respectively. The expression of autophagy-related proteins and Akt/mTOR signaling molecules were examined by Western blot. ROS generation was measured by DCFH-DA probe.

Results: We found that M-PDT induced cSCC apoptosis in a dose-dependent manner, and this result was related to autophagic flux blockage. The phenomenon is confirmed by the results that M-PDT could induce autophagosomes accumulation and upregulate LC3-II and p62 expression. M-PDT elevated co-localization of RFP and GFP tandem-tagged LC3B puncta in cSCC cell, reflecting autophagic flux blockage, and this was confirmed by transmission electron microscopy. Furthermore, we noticed that M-PDT induced accumulated autophagosomes-dependent apoptosis via targeting ROS-mediated Akt/mTOR signaling. Suppression of Akt potentiated M-PDT-induced upregulation of LC3-II and p62 levels, whereas Akt activation and ROS inhibition rendered resistance to these events. In addition, we observed that lysosomal dysfunction was involved in M-PDT-triggered accumulated autophagosomes-dependent cSCC apoptosis.

Conclusion: Our data demonstrates that M-PDT inhibits cSCC through blocking Akt/mTOR-mediated autophagic flux.

Adverse reactions of ALA-PDT for the treatment of cutaneous diseases: A retrospective study

BACKGROUND

5-Aminolaevulinic acid photodynamic therapy (ALA-PDT) is an effective therapy for cutaneous diseases, such as precancers, superficial non melanoma skin cancers and certain inflammatory or viral conditions. However, the absence of a complete picture of adverse reactions limits the promotion of ALA-PDT.

OBJECTIVE

To systemically investigate the detailed evidence of adverse reactions relating to ALA-PDT for skin diseases.

METHODS

A retrospective study performed at the Shanghai Skin Disease Hospital.

RESULTS

In the retrospective study, 439 patients were included. Incidences of adverse reactions, including in-treatment pain (98.8%), erythema (92.4%), edema (35.0%), exudation (23.0%), hyperpigmentation (27.3%) were clarified. Edema was more common in female patients (P<0.05). Patients with HPV-related skin diseases were more likely to suffer erythema, edema or exudation (P<0.05). Hyperpigmentation was more likely to occur in skin appendage disorders (P<0.05). Fever (2.4%) and hypopigmentation (1.9%) are two neglected adverse reactions analyzed in detail. Fever is more prevalent in female patients. Hypopigmentation occurred predominantly in elderly with skin cancer or precancerosis lesions.

CONCLUSION

The results outline detailed information about the adverse reactions, including systemic reactions following ALA-PDT, assisting dermatologists in predicting and managing adverse reactions for greater efficacy and higher patient satisfaction.