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

Abstract: 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

Photodynamic Therapy, a Potential Therapy for Improve Cancer Management

Cancer is a mass of abnormal and detrimental cells in a given part of the body. The main elucidated cause is the uncontrolled growth and proliferation of those cells after the corruption of the physiological processes responsible for normal development and functioning. The advantage of adjuvant therapy, therapy done after surgery, is to prevent the occurring of symptoms and not necessarily to make sure of the integrity of mechanisms that are crucial in preventing abnormal cell proliferation such cell cycle regulation, cell death, which include autophagy, necrosis, and apoptosis. The understanding of dysregulated cell death mechanisms combined with suitable alternative cancer therapies could lead to novel treatment modalities for cancer. Currently, breast cancer is the leading occurring cancer in sub-Saharan women after that of the cervix. This potentially curable condition kills more than half of the diagnosed group, which consists mainly of females aged between 35 and 49 years and with 77% being in stages III and IV. The social economic status of populations coupled with the limited access to proper control strategies and infrastructures in sub-Saharan regions accentuate the burden of the disease. Photodynamic therapy (PDT) has shown great potential in treating breast cancer and even greater therapeutic outcomes can be obtained when combining PDT with other therapies such as immunotherapy or nanomedicine

Targeted Breast Cancer Treatment Using New Photochemotherapeutic Compounds

The deregulation of cell growth in milk-producing glands, milk-carrying tubes, or connective tissues is known as breast cancer. It originates from genetic mutations and has the ability to metastasize. Primary tumor cells repetitively divide and lead to inappropriate mechanisms, tumorigenesis, and carcinogenesis, characterized by improper cell type, function, lifetime, and self-destruction. The tumor-specific activation is considered to be an effective strategy for selective cancer destruction, which remains an issue with conventional therapeutic approaches. The tumor microenvironment can be regulated and adapted through an interaction between pH, proteins, and other factors. Principally, human breast cancer genes, BRCA1 and BRCA2, produce tumor suppressors that prevent changes in genetic materials, as well as ensure their stability. Photodynamic therapy is a targeted cancer modality that depends on the photochemotherapeutic agent and light characteristics used to activate the compound. The possibility of eradicating breast cancer depends on continuous development of therapeutic approaches using third-generation photochemotherapeutic compounds to improve targeting this cancer and its stem cells

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

Abstract: 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 mM 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)..

The influence of light on reactive oxygen species and NF-êB in disease progression

Abstract: Abstract: Reactive oxygen species (ROS) are important secondary metabolites that play major roles in signaling pathways, with their levels often used as analytical tools to investigate various cellular scenarios. They potentially damage genetic material and facilitate tumorigenesis by inhibiting certain tumor suppressors. In diabetic conditions, substantial levels of ROS stimulate oxidative stress through specialized precursors and enzymatic activity, while minimum levels are required for proper wound healing. Photobiomodulation (PBM) uses light to stimulate cellular mechanisms and facilitate the removal of oxidative stress. Photodynamic therapy (PDT) generates ROS to induce selective tumor destruction. The regulatory roles of PBM via crosstalk between ROS and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-êB) are substantial for the appropriate management of various conditions

Risk Factors Associated with Opportunistic Infections among People Living with HIV/AIDS and Receiving an Antiretroviral Therapy in Gabon, Central Africa.

The Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) is still one of the main causes of death in sub-Saharan Africa. Antiretroviral therapies (ARTs) have significantly improved the health conditions of people living with HIV/AIDS (PLWHA). Consequently, a significant drop in morbidity and mortality, along with a reduced incidence of opportunistic infections (OIs), has been observed. However, certain atypical and biological profiles emerge in ART patients post-examination. The objective of this study was to identify the risk factors that contributed to the onset of OIs in HIV patients undergoing ART in Gabon. Epidemiological and biological data were obtained from medical records (2017 to 2019) found at the outpatient treatment centre (CTA) of Franceville in Gabon. Samples for blood count, CD4, and viral load analysis at CIRMF were collected from PLWHA suffering from other pathogen-induced conditions. A survey was carried out and data were analysed using Rstudio 4.0.2 and Excel 2007 software. Biological and socio-demographic characteristics were examined concerning OIs through both a univariate analysis via Fisher's exact tests or chi2 (χ2), and a multivariate analysis via logistic regression. Out of the 300 participants initially selected, 223 were included in the study, including 154 (69.05%) women and 69 (30.95%) men. The mean age was 40 (38.6; 41.85), with individuals ranging from 2 to 77 years old. The study cohort was classified into five age groups (2 to 12, 20 to 29, 30 to 39, 40 to 49, and 50 to 77 years old), among which the groups aged 30 to 39 and 40 to 49 emerged as the largest, comprising 68 (30.5%) and 75 (33.6%) participants, respectively. It was noted that 57.9% of PLWHA had developed OIs and three subgroups were distinguished, with parasitic, viral, and bacterial infections present in 18%, 39.7%, and 55.4% of cases, respectively. There was a correlation between being male and having a low CD4 T-cell count and the onset of OIs. The study revealed a high overall prevalence of OIs, and extending the study to other regions of Gabon would yield a better understanding of the risk factors associated with the onset of these infections

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

Synthesis of zinc phthalocyanine-gold nanoparticles conjugated compounds and determination of photodynamic effects in a breast cancer cell line

D.Tech. (Biomedical Technology)Abstract: Cancer is a disease that occurs following mutations in the genes, which control cell growth. These mutations are caused by different causes and viral infections are among those. Cancer cells can conquer other cells and tissues causing changes to their deoxyribonucleic acids (DNA). Cancer appears almost incurable once it has started to metastasize and invade other body organs. At that stage, any therapeutic intervention was believed to cause more harm than curative effects (Gallucci, 1985; Kardinal and Yarbro, 1979). Late diagnosis and treatment reduces the possibility of an effective cure (He et al., 2007). The development of a malignant tumour from cells in the breast is known as breast cancer. Breast cancer is generally initiated in the stromal cells, which are fibrous and fatty tissues, or in the glandular cells; which produce breast milk (American Cancer Society, 2014). Breast cancer is the leading cancer among women and cause of cancer death worldwide (Ferlay et al., 2008). It is a heterogeneous disease with several markers, which are essential for diagnosis and include the estrogen receptors (ER), progesterone receptors (PR) and human epidermal growth factor receptor 2 (HER-2) (Mosoyan et al., 2013; Yang et al., 2013). Like all cancer, breast cancer can be cured if diagnosed at an early stage. Treatment of cancer has evolved from palliative therapies to conventional therapies, which consist of surgery, hormonal therapy, radiation therapy, immunotherapy, chemotherapy, and adjuvant therapy. (Gallucci, 1985; Kardinal and Yarbro, 1979). Photodynamic therapy (PDT) has become popular as an alternative cancer treatment modality. PDT depends on molecular oxygen and photodynamic action for effective cancer destruction (Von Tappeiner and Jesionek, 1903; Von Tappeiner and Joblauer, 1904). Today, PDT is designated as a chronological and minimally invasive cancer therapy with numerous benefits over conventional treatments. The initial step of this therapy consists of the administration of drugs to patients,.

Effectiveness of zinc-phthalocyanine and hypericin in inducing cell death in human breast cancer cells (mcf-7) using low intensity laser irradiation (lili)

M.Tech. (Biomedical Technology)The uncontrolled growth of cells in the body is often associated with cancer. It constitutes a major health problem and is one of the leading causes of death in the world. Cancers of the lung, breast, colon/rectum and prostate are no longer only associated with developed countries but are the most common occurring cancers worldwide. Breast cancer is the leading cancer faced by women in South Africa as well as in the world. Conventional cancer therapies often result in uncertain outcomes with numerous side effects and may be associated with limited therapeutic advantage. This has led to the development of safer and better treatment regimes with improved therapeutic outcomes. Photodynamic therapy (PDT) is a treatment used for a wide range of conditions, including cancer. This treatment utilises a photosensitiser (PS), a light activated chemotherapeutic agent, and light of a specific wavelength and power density. It is based on the selective tumour localisation of the PS and the ability to generate high levels of reactive oxygen species (ROS) in the presence of light. The generation of ROS causes permanent damage to the tumour cells resulting in cancer cell death. The distinctive criteria when comparing different PDT modalities is the choice of PS as the treatment outcomes are greatly influenced by the light dependent properties of the chemotherapeutic agent. Phthalocyanines are second generation PSs used in PDT. Effects of members of this PS family have been studied and they exhibited good photosensitising properties including lack of cytotoxicity in the absence of light, extended retention times in the tumour and high triplet lifetime of singlet oxygen species

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