Effects of meta-tetrahydroxyphenylchlorin photodynamic therapy on isogenic colorectal cancer SW480 and SW620 cells with different metastatic potentials

Antitumor effects of a novel photosensitizer-mediated photodynamic therapy and its influence on the cell transcriptome

Photodynamic therapy (PDT) is a promising cancer treatment. This study investigated the antitumor effects and mechanisms of a novel photosensitizer meso-5-[ρ-diethylene triamine pentaacetic acid-aminophenyl]-10,15,20-triphenyl-porphyrin (DTP) mediated PDT (DTP-PDT). Cell viability, reactive oxygen species (ROS), and apoptosis were measured with a Cell Counting Kit-8 assay, DCFH-DA fluorescent probe, and Hoechst staining, respectively. Cell apoptosis- and autophagy-related proteins were examined using western blotting. RNA sequencing was used to screen differentially expressed mRNAs (DERs), and bioinformatic analysis was performed to identify the major biological events after DTP-PDT. Our results show that DTP-PDT inhibited cell growth and induced ROS generation in MCF-7 and SGC7901 cells. The ROS scavenger N-acetyl-L-cysteine (NAC) and the P38 MAPK inhibitor SB203580 alleviated DTP-PDT-induced cytotoxicity. DTP-PDT induced cell apoptosis together with upregulated Bax and downregulated Bcl-2, which could also be inhibited by NAC or SB203580. The level of LC3B-II, a marker of autophagy, was increased by DTP-PDT. A total of 3496 DERs were obtained after DTP-PDT. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that DERs included those involved in cytosolic ribosomes, the nuclear lumen, protein binding, cell cycle, protein targeting to the endoplasmic reticulum, and ribosomal DNA replication. Disease Ontology and Reactome enrichment analyses indicated that DERs were associated with a variety of cancers and cell cycle checkpoints. Protein-protein interaction results demonstrated that cdk1 and rps27a ranked in the top 10 interacting genes. Therefore, DTP-PDT could inhibit cell growth and induce cell apoptosis and autophagy, partly through ROS and the P38 MAPK signaling pathway. Genes associated with the cell cycle, ribosomes, DNA replication, and protein binding may be the key changes in DTP-PDT-mediated cytotoxicity.

Photodynamic Therapy and Immunological View in Gastrointestinal Tumors

Gastrointestinal cancers are a specific group of oncological diseases in which the location and nature of growth are of key importance for clinical symptoms and prognosis. At the same time, as research shows, they pose a serious threat to a patient's life, especially at an advanced stage of development. The type of therapy used depends on the anatomical location of the cancer, its type, and the degree of progression. One of the modern forms of therapy used to treat gastrointestinal cancers is PDT, which has been approved for the treatment of esophageal cancer in the United States. Despite the increasingly rapid clinical use of this treatment method, the exact immunological mechanisms it induces in cancer cells has not yet been fully elucidated. This article presents a review of the current understanding of the mode of action of photodynamic therapy on cells of various gastrointestinal cancers with an emphasis on colorectal cancer. The types of cell death induced by PDT include apoptosis, necrosis, and pyroptosis. Anticancer effects are also a result of the destruction of tumor vasculature and activation of the immune system. Many reports exist that concern the mechanism of apoptosis induction, of which the mitochondrial pathway is most often emphasized. Photodynamic therapy may also have a beneficial effect on such aspects of cancer as the ability to develop metastases or contribute to reducing resistance to known pharmacological agents.

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.

Up-regulation of ABCG2 by MYBL2 deletion drives Chlorin e6-mediated photodynamic therapy resistance in colorectal cancer

OBJECTIVE

Photodynamic therapy (PDT) is an effective therapeutic strategy for colorectal cancer at an early stage. However, malignant cells' resistance to photodynamic agents can lead to treatment failure. MYBL2 (B-Myb) is an oncogene in colorectal carcinogenesis and development, for which little research has focused on its effect on drug resistance.

MATERIALS AND METHODS

In the present work, a colorectal cancer cell line with a stable knockdown of MYBL2 (ShB-Myb) was constructed first. Chlorin e6 (Ce6) was utilized to induced PDT. The anti-cancer efficacy was measured by CCK-8, PI staining, and Western blots. The drug uptake of Ce6 was assayed by flow cytometry and confocal microscopy. The ROS generation was detected by the CellROX probe. DDSB and DNA damage were assayed through comet experiment and Western blots. The over-expression of MYBL2 was conducted by MYBL2 plasmid.

RESULTS

The findings indicated that the viability of ShB-Myb treated with Ce6-PDT was not decreased compared to control SW480 cells (ShNC), which were resistant to PDT. Further investigation revealed reduced photosensitizer enrichment and mitigated oxidative DNA damage in colorectal cancer cells with depressed MYBL2. It turned out that SW480 cells knocking down MYBL2 showed phosphorylation of NF-κB and led to up-regulation of ABCG2 expression thereupon. When MYBL2 was replenished back in MYBL2-deficient colorectal cancer cells, phosphorylation of NF-κB was blocked and ABCG2 expression up-regulation was suppressed. Additionally, replenishment of MYBL2 also increased the enrichment of Ce6 and the efficacy of PDT.

CONCLUSION

In summary, MYBL2 absence in colorectal cancer contributes to drug resistance by activating NF-κB to up-regulate ABCG2 and thereby leading to photosensitizer Ce6 efflux. This study provides a novel theoretical basis and strategy for how to effectively improve the anti-tumor efficacy of PDT.

Porphyrin/Chlorin Derivatives as Promising Molecules for Therapy of Colorectal Cancer

Colorectal cancer (CRC) is a leading cause of cancer-related death. The demand for new therapeutic approaches has increased attention paid toward therapies with high targeting efficiency, improved selectivity and few side effects. Porphyrins are powerful molecules with exceptional properties and multifunctional uses, and their special affinity to cancer cells makes them the ligands par excellence for anticancer drugs. Porphyrin derivatives are used as the most important photosensitizers (PSs) for photodynamic therapy (PDT), which is a promising approach for anticancer treatment. Nevertheless, the lack of solubility and selectivity of the large majority of these macrocycles led to the development of different photosensitizer complexes. In addition, targeting agents or nanoparticles were used to increase the efficiency of these macrocycles for PDT applications. On the other hand, gold tetrapyrrolic macrocycles alone showed very interesting chemotherapeutic activity without PDT. In this review, we discuss the most important porphyrin derivatives, alone or associated with other drugs, which have been found effective against CRC, as we describe their modifications and developments through substitutions and delivery systems.

A mathematical model of the circadian clock and drug pharmacology to optimize irinotecan administration timing in colorectal cancer

Scheduling anticancer drug administration over 24 h may critically impact treatment success in a patient-specific manner. Here, we address personalization of treatment timing using a novel mathematical model of irinotecan cellular pharmacokinetics and -dynamics linked to a representation of the core clock and predict treatment toxicity in a colorectal cancer (CRC) cellular model. The mathematical model is fitted to three different scenarios: mouse liver, where the drug metabolism mainly occurs, and two human colorectal cancer cell lines representing an in vitro experimental system for human colorectal cancer progression. Our model successfully recapitulates quantitative circadian datasets of mRNA and protein expression together with timing-dependent irinotecan cytotoxicity data. The model also discriminates time-dependent toxicity between the different cells, suggesting that treatment can be optimized according to their cellular clock. Our results show that the time-dependent degradation of the protein mediating irinotecan activation, as well as an oscillation in the death rate may play an important role in the circadian variations of drug toxicity. In the future, this model can be used to support personalized treatment scheduling by predicting optimal drug timing based on the patient's gene expression profile.

Effects of jasplakinolide on cytotoxicity, cytoskeleton and apoptosis in two different colon cancer cell lines treated with m-THPC-PDT

Colorectal cancer (CRC) is a common malignant tumor, and metastasis is one of the most important challenges in the treatment of CRC. Photodynamic therapy (PDT) is a novel and non-invasive treatment that influence cytoskeleton and to reduce cancer metastases. In addition, cytoskeleton is related to cancer metastases. Two isogenic colorectal cancer cell lines SW480 and SW620 were used in the present study, we found that m-THPC mediated PDT changed the cytotoxicity, apoptosis and cytoskeleton in both cell lines. Interestingly, the expression of intermediate filaments protein cytokeratin18 were different in the two cell lines. In order to further confirm the relationship between cytoskeleton and cell migration, we combined with microfilament stabilizer jasplakinolide (JASP) to observe the effects of microfilaments on cell migration, cytotoxicity and apoptosis. Taken together, these findings suggest that m-THPC-PDT could induce cytoplasmic cytoskeleton destruction in both types of cells, especially on microfilaments and microtubules. Moreover, in SW480 cells, microtubules may participate in the apoptosis process induced by m-THPC-PDT, while microfilaments may participate in the process of m-THPC-PDT inhibiting cell migration. But in SW620 cells, only microfilaments may be involved in m-THPC-PDT induced apoptosis and inhibition of cell migration.

Possible Enhancement of Photodynamic Therapy (PDT) Colorectal Cancer Treatment when Combined with Cannabidiol

Colorectal Cancer (CRC) has a high mortality rate and is one of the most difficult diseases to manage due to tumour resistance and metastasis. The treatment of choice for CRC is reliant on the phase and time of diagnosis. Despite several conventional treatments available to treat CRC (surgical excision, chemo-, radiationand immune-therapy), resistance is a major challenge, especially if it has metastasized. Additionally, these treatments often cause unwanted adverse side effects and so it remains imperative to investigate alternative combination therapies. Photodynamic Therapy (PDT) is a promising treatment modality for the primary treatment of CRC, since it is non-invasive, has few side effects and selectively damages only cancerous tissues, leaving adjacent healthy structures intact. PDT involves three fundamentals: a Photosensitizer (PS) drug localized in tumour tissues, oxygen, and light. Upon PS excitation using a specific wavelength of light, an energy transfer cascade occurs, that ultimately yields cytotoxic species, which in turn induces cell death. Cannabidiol (CBD) is a cannabinoid compound derived from the Cannabis sativa plant, which has shown to exert anticancer effects on CRC through different pathways, inducing apoptosis and so inhibiting tumour metastasis and secondary spread. This review paper highlights current conventional treatment modalities for CRC and their limitations, as well as discusses the necessitation for further investigation into unconventional active nanoparticle targeting PDT treatments for enhanced primary CRC treatment. This can be administered in combination with CBD, to prevent CRC secondary spread and enhance the synergistic efficacy of CRC treatment outcomes, with less side effects.

Paraptosis after ER Photodamage Initiated by m-tetra(hydroxyphenyl) Chlorin

Two cell lines, A549 (human-derived nonsmall-cell lung cancer) and 1c1c7 (mouse hepatoma), were photosensitized with m-THPC and irradiated under LD₉₀ conditions. After 4 h, a pattern of cytoplasmic vacuoles had formed consistent with the initiation of paraptosis. After irradiation, there was no detectable loss of the mitochondrial membrane potential indicating no significant photodamage to mitochondria. We did, however, observe localization of m-THPC in the endoplasmic reticulum (ER), as indicated by fluorescence microscopy. Subsequent ER perturbation is known to result in initiation of paraptosis, another pathway to cell death. While an apoptotic response to m-THPC has been reported, the ability to target ER and induce paraptosis could explain the efficacy of this agent which could therefore eradicate cell types with an impaired apoptotic response.

Photodynamic therapy induces autophagy-mediated cell death in human colorectal cancer cells via activation of the ROS/JNK signaling pathway

Evidence has shown that m-THPC and verteporfin (VP) are promising sensitizers in photodynamic therapy (PDT). In addition, autophagy can act as a tumor suppressor or a tumor promoter depending on the photosensitizer (PS) and the cancer cell type. However, the role of autophagy in m-THPC- and VP-mediated PDT in in vitro and in vivo models of human colorectal cancer (CRC) has not been reported. In this study, m-THPC-PDT or VP-PDT exhibited significant phototoxicity, inhibited proliferation, and induced the generation of large amounts of reactive oxygen species (ROS) in CRC cells. From immunoblotting, fluorescence image analysis, and transmission electron microscopy, we found extensive autophagic activation induced by ROS in cells. In addition, m-THPC-PDT or VP-PDT treatment significantly induced apoptosis in CRC cells. Interestingly, the inhibition of m-THPC-PDT-induced autophagy by knockdown of ATG5 or ATG7 substantially inhibited the apoptosis of CRC cells. Moreover, m-THPC-PDT treatment inhibited tumorigenesis of subcutaneous HCT116 xenografts. Meanwhile, antioxidant treatment markedly inhibited autophagy and apoptosis induced by PDT in CRC cells by inactivating JNK signaling. In conclusion, inhibition of autophagy can remarkably alleviate PDT-mediated anticancer efficiency in CRC cells via inactivation of the ROS/JNK signaling pathway. Our study provides evidence for the therapeutic application of m-THPC and VP in CRC.

Physical approaches to treat glioblastoma

PURPOSE OF REVIEW

Glioblastoma (GBM) patients have a poor prognosis despite the use of modern synergistic multimodal treatment strategies, with a progression-free survival estimated at 7-8 months, a median survival of 14-16 months and 5-year overall survival of 9.8%.

RECENT FINDINGS

Physical methods hold the promise to act synergistically with classical treatments to improve the outcome of GBM patients. Fluorescent guided surgery with 5-aminolevulinic acid and tumor-treating fields therapy have already shown positive results in randomized phase III trials and have been incorporated in the standard management. Other techniques such as photodynamic therapy (PDT) and focused ultrasound, often combined whit microbubbles, are reaching clinical development.

SUMMARY

Several clinical trials to evaluate the feasibility and efficacy of ultrasound devices to disrupt the blood-brain barrier are ongoing. PDT enables the creation of a safety margin or treatment of non-resecable tumors. However, randomized trials are urgently required to validate the efficacy of these promising approaches. We aim to critically review physical approaches to treat GBM, focusing on available clinical trial data.

Photodynamic therapy regulates fate of cancer stem cells through reactive oxygen species

Photodynamic therapy (PDT) is an effective and promising cancer treatment. PDT directly generates reactive oxygen species (ROS) through photochemical reactions. This oxygen-dependent exogenous ROS has anti-cancer stem cell (CSC) effect. In addition, PDT may also increase ROS production by altering metabolism, endoplasmic reticulum stress, or potential of mitochondrial membrane. It is known that the half-life of ROS in PDT is short, with high reactivity and limited diffusion distance. Therefore, the main targeting position of PDT is often the subcellular localization of photosensitizers, which is helpful for us to explain how PDT affects CSC characteristics, including differentiation, self-renewal, apoptosis, autophagy, and immunogenicity. Broadly speaking, excess ROS will damage the redox system and cause oxidative damage to molecules such as DNA, change mitochondrial permeability, activate unfolded protein response, autophagy, and CSC resting state. Therefore, understanding the molecular mechanism by which ROS affect CSCs is beneficial to improve the efficiency of PDT and prevent tumor recurrence and metastasis. In this article, we review the effects of two types of photochemical reactions on PDT, the metabolic processes, and the biological effects of ROS in different subcellular locations on CSCs.

Using Light for Therapy of Glioblastoma Multiforme (GBM)

: Glioblastoma multiforme (GBM) is the most malignant form of primary brain tumour with extremely poor prognosis. The current standard of care for newly diagnosed GBM includes maximal surgical resection followed by radiotherapy and adjuvant chemotherapy. The introduction of this protocol has improved overall survival, however recurrence is essentially inevitable. The key reason for that is that the surgical treatment fails to eradicate GBM cells completely, and adjacent parenchyma remains infiltrated by scattered GBM cells which become the source of recurrence. This stimulates interest to any supplementary methods which could help to destroy residual GBM cells and fight the infiltration. Photodynamic therapy (PDT) relies on photo-toxic effects induced by specific molecules (photosensitisers) upon absorption of photons from a light source. Such toxic effects are not specific to a particular molecular fingerprint of GBM, but rather depend on selective accumulation of the photosensitiser inside tumour cells or, perhaps their greater sensitivity to the effects, triggered by light. This gives hope that it might be possible to preferentially damage infiltrating GBM cells within the areas which cannot be surgically removed and further improve the chances of survival if an efficient photosensitiser and hardware for light delivery into the brain tissue are developed. So far, clinical trials with PDT were performed with one specific type of photosensitiser, protoporphyrin IX, which tends to accumulate in the cytoplasm of the GBM cells. In this review we discuss the idea that other types of molecules which build up in mitochondria could be explored as photosensitisers and used for PDT of these aggressive brain tumours.

Photodynamic diagnosis and photodynamic therapy of colorectal cancer in vitro and in vivo

This review highlights the various photo diagnostic and treatment methods utilized for CRC, over the last seven years.

The effects of photodynamic therapy on leukemia cells mediated by KillerRed, a genetically encoded fluorescent protein photosensitizer

BACKGROUND

Leukemia is a cancer of blood and bone marrow cells, causing about 300,000 deaths worldwide. Photodynamic therapy (PDT) is a promising alternative for the treatment of malignant tumors. KillerRed is a genetically encoded red fluorescent protein photosensitizer (PS). In this study, we aimed to investigate the effects of KillerRed-mediated PDT on chronic myelogenous leukemia K562 cells, acute monocytic leukemia NB4 cells, and acute monocytic leukemia THP1 cells.

METHODS

KillerRed was expressed in Escherichia coli cells, purified by Q-Sepharose column, and confirmed by western-blotting. The PDT effect on cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8). Cell apoptosis was determined by PE Annexin V/7-AAD staining and flow cytometry. The distribution of KillerRed in leukemia cells was detected by confocal laser scanning microscopy (CLSM) and western-blotting. The ROS generation was measured by flow cytometry.

RESULTS

Pure KillerRed was obtained with a yield of about 37 mg per liter of bacterial cells. KillerRed photodynamic inactivated the leukemia cells in a concentration-dependent manner, but exhibited no obvious dark toxicity. PDT mediated by KillerRed could also induce apoptotic response (mainly early apoptosis) in the three cell lines. The CLSM imaging indicated that KillerRed was distributed within the cytoplasm and nuclei of leukemia cells, causing damages to the cytoplasm and leaving the nuclear envelope intact during light irradiation. KillerRed distributed both in the cytosol and nuclei was confirmed by western blotting, and ROS significantly increased in PDT treated cells compared to the cells treated with KillerRed alone.

CONCLUSIONS

Our studies demonstrated that KillerRed-mediated PDT could effectively inactivate K562, NB4, and THP1 leukemia cells and trigger cell apoptosis, and it has potential to be used individually or complementally, in the treatment of leukemia.

Comparison of Cellular Death Pathways after mTHPC-mediated Photodynamic Therapy (PDT) in Five Human Cancer Cell Lines

One of the most promising photosensitizers (PS) used in photodynamic therapy (PDT) is the porphyrin derivative 5,10,15,20-tetra(m-hydroxyphenyl)chlorin (mTHPC, temoporfin), marketed in Europe under the trade name Foscan^®. A set of five human cancer cell lines from head and neck and other PDT-relevant tissues was used to investigate oxidative stress and underlying cell death mechanisms of mTHPC-mediated PDT in vitro. Cells were treated with mTHPC in equitoxic concentrations and illuminated with light doses of 1.8-7.0 J/cm² and harvested immediately, 6, 24, or 48 h post illumination for analyses. Our results confirm the induction of oxidative stress after mTHPC-based PDT by detecting a total loss of mitochondrial membrane potential (Δψ_m) and increased formation of ROS. However, lipid peroxidation (LPO) and loss of cell membrane integrity play only a minor role in cell death in most cell lines. Based on our results, apoptosis is the predominant death mechanism following mTHPC-mediated PDT. Autophagy can occur in parallel to apoptosis or the former can be dominant first, yet ultimately leading to autophagy-associated apoptosis. The death of the cells is in some cases accompanied by DNA fragmentation and a G₂/M phase arrest. In general, the overall phototoxic effects and the concentrations as well as the time to establish these effects varies between cell lines, suggesting that the cancer cells are not all dying by one defined mechanism, but rather succumb to an individual interplay of different cell death mechanisms. Besides the evaluation of the underlying cell death mechanisms, we focused on the comparison of results in a set of five identically treated cell lines in this study. Although cells were treated under equitoxic conditions and PDT acts via a rather unspecific ROS formation, very heterogeneous results were obtained with different cell lines. This study shows that general conclusions after PDT in vitro require testing on several cell lines to be reliable, which has too often been ignored in the past.