PPAR γ agonist, pioglitazone, suppresses melanoma cancer in mice by inhibiting TLR4 signaling

The nexus of natural killer cells and melanoma tumor microenvironment: crosstalk, chemotherapeutic potential, and innovative NK cell-based therapeutic strategies

The metastasis of melanoma cells to regional lymph nodes and distant sites is an important contributor to cancer-related morbidity and mortality among patients with melanoma. This intricate process entails dynamic interactions involving tumor cells, cellular constituents, and non-cellular elements within the microenvironment. Moreover, both microenvironmental and systemic factors regulate the metastatic progression. Central to immunosurveillance for tumor cells are natural killer (NK) cells, prominent effectors of the innate immune system with potent antitumor and antimetastatic capabilities. Recognizing their pivotal role, contemporary immunotherapeutic strategies are actively integrating NK cells to combat metastatic tumors. Thus, a meticulous exploration of the interplay between metastatic melanoma and NK cells along the metastatic cascade is important. Given the critical involvement of NK cells within the melanoma tumor microenvironment, this comprehensive review illuminates the intricate relationship between components of the melanoma tumor microenvironment and NK cells, delineating their multifaceted roles. By shedding light on these critical aspects, this review advocates for a deeper understanding of NK cell dynamics within the melanoma context, driving forward transformative strategies to combat this cancer.

Understanding the Role of Adipocytes and Fibroblasts in Cancer

ABSTRACT

Cancer is currently the second leading cause of death in the United States. There is increasing evidence that the tumor microenvironment (TME) is pivotal for tumorigenesis and metastasis. Recently, adipocytes and cancer-associated fibroblasts (CAFs) in the TME have been shown to play a major role in tumorigenesis of different cancers, specifically melanoma. Animal studies have shown that CAFs and adipocytes within the TME help tumors evade the immune system, for example, by releasing chemokines to blunt the effectiveness of the host defense. Although studies have identified that adipocytes and CAFs play a role in tumorigenesis, adipocyte transition to fibroblast within the TME is fairly unknown. This review intends to elucidate the potential that adipocytes may have to transition to fibroblasts and, as part of the TME, a critical role that CAFs may play in affecting the growth and invasion of tumor cells. Future studies that illuminate the function of adipocytes and CAFs in the TME may pave way for new antitumor therapies.

Castration promotes the browning of the prostate tumor microenvironment

BACKGROUND

Adipose tissue has gained attention due to its potential paracrine role. Periprostatic adipose tissue surrounds the prostate and the prostatic urethra, and it is an essential player in prostate cancer progression. Since obesity is directly related to human tumor progression, and adipose tissue depots are one of the significant components of the tumor microenvironment, the molecular mediators of the communication between adipocytes and epithelial cells are in the spotlight. Although periprostatic white adipose tissue contributes to prostate cancer progression, brown adipose tissue (BAT), which has beneficial effects in metabolic pathologies, has been scarcely investigated concerning cancer progression. Given that adipose tissue is a target of androgen signaling, the actual role of androgen removal on the periprostatic adipose tissue was the aim of this work.

METHODS

Surgical castration of the transgenic adenocarcinoma of the mouse prostate (TRAMP) was employed. By histology examination and software analysis, WAT and BAT tissue was quantified. 3T3-like adipocytes were used to study the role of Casodex® in modifying adipocyte differentiation and to investigate the function of the secretome of adipocytes on the proliferation of androgen-dependent and independent prostate cancer cells. Finally, the role of cell communication was assayed by TRAMP-C1 xenograft implanted in the presence of 3T3-like adipocytes.

RESULTS

Androgen removal increases brown/beige adipose tissue in the fat immediately surrounding the prostate glands of TRAMP mice, concomitant with an adjustment of the metabolism. Castration increases body temperature, respiratory exchange rate, and energy expenditure. Also, in vitro, it is described that blocking androgen signaling by Casodex® increases the uncoupling protein 1 (UCP1) marker in 3T3-like adipocytes. Finally, the effect of brown/beige adipocyte secretome was studied on the proliferation of prostate cancer cells in vivo and in vitro. The secretome of brown/beige adipocytes reduces the proliferation of prostate cancer cells mediated partly by the secretion of extracellular vesicles.

CONCLUSIONS

Consequently, we concluded that hampering androgen signaling plays a crucial role in the browning of the periprostatic adipose tissue. Also, the presence of brown adipocytes exhibits the opposite effect to that of white adipocytes in vitro regulating processes that govern the mechanisms of cell proliferation of prostate cancer cells. And finally, promoting the browning of adipose tissue in the periprostatic adipose tissue might be a way to handle prostate cancer cell progression. Video Abstract.

PPARs and the Kynurenine Pathway in Melanoma-Potential Biological Interactions

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in various physiological and pathological processes within the skin. PPARs regulate several processes in one of the most aggressive skin cancers, melanoma, including proliferation, cell cycle, metabolic homeostasis, cell death, and metastasis. In this review, we focused not only on the biological activity of PPAR isoforms in melanoma initiation, progression, and metastasis but also on potential biological interactions between the PPAR signaling and the kynurenine pathways. The kynurenine pathway is a major pathway of tryptophan metabolism leading to nicotinamide adenine dinucleotide (NAD+) production. Importantly, various tryptophan metabolites exert biological activity toward cancer cells, including melanoma. Previous studies confirmed the functional relationship between PPAR and the kynurenine pathway in skeletal muscles. Despite the fact this interaction has not been reported in melanoma to date, some bioinformatics data and biological activity of PPAR ligands and tryptophan metabolites may suggest a potential involvement of these metabolic and signaling pathways in melanoma initiation, progression, and metastasis. Importantly, the possible relationship between the PPAR signaling pathway and the kynurenine pathway may relate not only to the direct biological effect on melanoma cells but also to the tumor microenvironment and the immune system.

Research progress of PPARγ regulation of cholesterol and inflammation in Alzheimer's disease

Peroxidase proliferator receptors (PPARs) are defined as key sensors and regulators of cell metabolism, transcription factors activated by ligands, involved in lipid, glucose and amino acid metabolism, participating in the processes of cell differentiation, apoptosis, inflammation regulation, and acute and chronic nerve damage. Among them, PPARγ is expressed in different brain regions and can regulate lipid metabolism, mitochondrial disorders, oxidative stress, and cell apoptosis. It has anti-inflammatory activity and shows neuroprotection. The regulation of Aβ levels in Alzheimer's disease involves cholesterol metabolism and inflammation, so this article first analyzes the biological functions of PPARγ, then mainly focuses on the relationship between cholesterol and inflammation and Aβ, and elaborates on the regulation of PPARγ on key proteins and the corresponding molecules, which provides new ideas for the treatment of AD.

Pomegranate Peel Extract Sensitizes Hepatocellular Carcinoma Cells to Ionizing Radiation, Induces Apoptosis and Inhibits MAPK, JAK/STAT3, β-Catenin/NOTCH, and SOCS3 Signaling

Tumor resistance is typically blamed for the failure of radiotherapy and chemotherapy to treat cancer in clinic patients. To improve the cytotoxicity of tumor cells using radiation in conjunction with specific tumor-selective cytotoxic drugs is crucial. Pomegranate has received overwhelmingly positive feedback as a highly nutritious food for enhancing health and treating a variety of ailments. In the present study, we aimed to examine the effects as well as mechanism of action of pomegranate peel extract (PPE) and/or γ-radiation (6-Gy) on hepatocellular carcinoma (HCC) cell lines HepG2. The findings of this study showed that PPE treatment of HepG2 cells considerably slowed the proliferation of cancer cells, and its combination with γ-irradiation potentiated this action. As a key player in tumor proliferation, and inflammatory cascade induction, the down-regulation of STAT3 following treatment of irradiated and non-irradiated HepG2 cells with PPE as recorded in the present work resulted in reduction of tumor growth, via modulating inflammatory response manifested by (down-regulation of TLR4 expression and NFKB level), suppressing survival markers expressed by reduction of JAK, NOTCH1, β-catenin, SOCS3, and enhancing apoptosis (induction of tumor PPAR-γ and caspase-3) followed by changes in redox tone (expressed by increase in Nrf-2, SOD and catalase activities, and decrease in MDA concentration). In conclusion, PPE might possess a considerable therapeutic potential against HCC in addition to its capability to enhance response of HepG2 cells to gamma radiation.

Effects of Methadone on the Toll-like Receptor 4 Expression in Human Non-Small Cell Lung Carcinoma A549 Cell Line Using In-silico and In vitro Techniques

Background

In this study, the effects of methadone and naloxone on the expression of toll-like receptor 4 (TLR4) gene have been evaluated in human non-small cell lung carcinoma A549 cell line migration using in-silico and in vitro techniques.

Materials and Methods

Lung cancer A549 cell cultures were stimulated for 24 h with methadone (5, 10, and 20 μM) and naloxone (20 and 40 μM) concentrations. The level of TLR4 expression was determined by the quantitative real-time polymerase chain reaction. Migration of the A549 cells was investigated after a 4-h incubation period with methadone using the Boyden Chamber assay.

Results

Migration rate of the A549 cells treated with 5 (P < 0.05) and 20 (P < 0.01) μM methadone was, respectively, increased and decreased with 20 μM naloxone (P < 0.05). Furthermore, the TLR4 expression was enhanced with 5 (P < 0.05) and 20 (P < 0.01) μM methadone and decreased with 20 (P < 0.05) and 40 μM naloxone (P < 0.01). In addition, in silico docking analysis revealed docking of methadone to MD-2 and TLR4.

Conclusion

According to the present DATA, methadone affects the TLR4 expression. It may however cause adverse consequences by increasing the TLR4 expression. Therefore, the useful analgesic properties of methadone should be separated from the unwanted TLR4-mediated side effects.

PPARγ activation by pioglitazone enhances the anti-proliferative effects of doxorubicin on pro-monocytic THP-1 leukemia cells via inducing apoptosis and G2/M cell cycle arrest

PURPOSE

Doxorubicin (DOX) is a common chemotherapeutic agent, with toxic side effects, and chemoresistance. Combination chemotherapy is a successful approach to overcome these limitations. Here, we investigated the effects of pioglitazone (PGZ), a PPARγ agonist, and/or DOX on the viability, cell cycle, apoptosis on THP-1 cells and normal human monocytes (NHMs).

METHODS

MTT assay was used to evaluate the cytotoxicity of DOX and/or PGZ. Cell cycle progression and apoptosis induction were examined by PI or Annexin V-PI double staining, and analyzed by flow cytometry. Quantitative RT-PCR was used to evaluate the changes in the mRNA expression of cell cycle progression or apoptosis-associated genes including P27, P21, CDK2, P53, BCL2 and FasR.

RESULTS

DOX, PGZ and DOX + PGZ exerted their cytotoxic effects in a dose- and time-dependent manner with low toxicity on NHMs. The cell growth inhibitory effects of DOX were in association with G2/M arrest, while PGZ executed S phase arrest. PGZ treatment enhanced G2/M among DOX-treated combinations with moderate elevation in the S phase. DOX, PGZ and combined treatments induced apoptosis (mostly late phase) in a dose-dependent manner. All treatments resulted in the significant overexpression of p21, p27, p53 and FasR genes and downregulation of CDK2. DOX + PGZ combined treatments exhibited the most significant changes in mRNA expression.

CONCLUSION

We demonstrated that the antiproliferative, cell cycle regulation and apoptosis-inducing capacity of DOX was enhanced by PGZ in THP-1 leukemia cells in a dose-dependent manner. Therefore, the combination of DOX + PGZ could be used as a novel combination to target AML.

PTPRO represses colorectal cancer tumorigenesis and progression by reprogramming fatty acid metabolism

BACKGROUND

Abnormal expression of protein tyrosine phosphatases (PTPs) has been reported to be a crucial cause of cancer. As a member of PTPs, protein tyrosine phosphatase receptor type O (PTPRO) has been revealed to play tumor suppressive roles in several cancers, while its roles in colorectal cancer (CRC) remains to be elucidated. Hence, we aimed to explore the roles and mechanisms of PTPRO in CRC initiation and progression.

METHODS

The influences of PTPRO on the growth and liver metastasis of CRC cells and the expression patterns of different lipid metabolism enzymes were evaluated in vitro and in vivo. Molecular and biological experiments were conducted to uncover the underpinning mechanisms of dysregulated de novo lipogenesis and fatty acid β-oxidation.

RESULTS

PTPRO expression was notably downregulated in CRC liver metastasis compared to the primary cancer, and such a downregulation was associated with poor prognosis of patients with CRC. PTPRO silencing significantly promoted cell growth and liver metastasis. Compared with PTPRO wild-type mice, PTPRO-knockout mice developed more tumors and harbored larger tumor loads under treatment with azoxymethane and dextran sulfate sodium. Gene set enrichment analysis revealed that PTPRO downregulation was significantly associated with the fatty acid metabolism pathways. Blockage of fatty acid synthesis abrogated the effects of PTPRO silencing on cell growth and liver metastasis. Further experiments indicated that PTPRO silencing induced the activation of the AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) signaling axis, thus promoting de novo lipogenesis by enhancing the expression of sterol regulatory element-binding protein 1 (SREBP1) and its target lipogenic enzyme acetyl-CoA carboxylase alpha (ACC1) by activating the AKT/mTOR signaling pathway. Furthermore, PTPRO attenuation decreased the fatty acid oxidation rate by repressing the expression of peroxisome proliferator-activated receptor alpha (PPARα) and its downstream enzyme peroxisomal acyl-coenzyme A oxidase 1 (ACOX1) via activating the p38/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway.

CONCLUSIONS

PTPRO could suppress CRC development and metastasis via modulating the AKT/mTOR/SREBP1/ACC1 and MAPK/PPARα/ACOX1 pathways and reprogramming lipid metabolism.

Pioglitazone, a Peroxisome Proliferator-Activated Receptor-γ Agonist, Downregulates the Inflammatory Response in Cutaneous Leishmaniasis Patients Without Interfering in Leishmania braziliensis Killing by Monocytes

Patients with cutaneous leishmaniasis (CL) due to Leishmania braziliensis infection have an exacerbated inflammatory response associated with tissue damage and ulcer development. An increase in the rate of patients who fail therapy with pentavalent antimony has been documented. An adjuvant therapy with an anti-inflammatory drug with the potential of Leishmania killing would benefit CL patients. The aim of the present study was to investigate the contribution of peroxisome proliferator-activated receptor-γ (PPAR-γ) activation by pioglitazone in the regulation of the inflammatory response and L. braziliensis killing by monocytes. Pioglitazone is an oral drug used in the treatment of diabetes, and its main mechanism of action is through the activation of PPAR-γ, which is expressed in many cell types of the immune response. We found that activation of PPAR-γ by pioglitazone decreases the inflammatory response in CL patients without affecting L. braziliensis killing by monocytes. Our data suggest that pioglitazone may serve as an adjunctive treatment for CL caused by L. braziliensis.

Drug Repurposing by Tumor Tissue Editing

The combinatory use of drugs for systemic cancer therapy commonly aims at the direct elimination of tumor cells through induction of apoptosis. An alternative approach becomes the focus of attention if biological changes in tumor tissues following combinatory administration of regulatorily active drugs are considered as a therapeutic aim, e.g., differentiation, transdifferentiation induction, reconstitution of immunosurveillance, the use of alternative cell death mechanisms. Editing of the tumor tissue establishes new biological 'hallmarks' as a 'pressure point' to attenuate tumor growth. This may be achieved with repurposed, regulatorily active drug combinations, often simultaneously targeting different cell compartments of the tumor tissue. Moreover, tissue editing is paralleled by decisive functional changes in tumor tissues providing novel patterns of target sites for approved drugs. Thus, agents with poor activity in non-edited tissue may reveal new clinically meaningful outcomes. For tissue editing and targeting edited tissue novel requirements concerning drug selection and administration can be summarized according to available clinical and pre-clinical data. Monoactivity is no pre-requisite, but combinatory bio-regulatory activity. The regulatorily active dose may be far below the maximum tolerable dose, and besides inhibitory active drugs stimulatory drug activities may be integrated. Metronomic scheduling often seems to be of advantage. Novel preclinical approaches like functional assays testing drug combinations in tumor tissue are needed to select potential drugs for repurposing. The two-step drug repurposing procedure, namely establishing novel functional systems states in tumor tissues and consecutively providing novel target sites for approved drugs, facilitates the systematic identification of drug activities outside the scope of any original clinical drug approvals.

Allicin attenuated hepatic ischemia/reperfusion injury in mice by regulating PPARγ-IRAK-M-TLR4 signal pathway

Background: Hepatic ischemia/reperfusion (I/R) injury to the liver is a significant cause of morbidity and mortality following liver surgery, trauma, and hemorrhagic shock. It was reported that allicin, a type of garlic compound, had a protective effect against other hepatic diseases. Allicin's ability to protect against liver injury caused by ischemic reperfusion remains unknown. As a result, we conducted this study to determine allicin's effects and mechanism of action in hepatic I/R injury. Method: The liver I/R injury model was established by clamping the blood supply to the left and middle liver lobes. Three days prior to the hepatic I/R injury, different concentrations of allicin were gavaged. Then, hepatic function, histological changes, apoptosis markers, oxidative stress, and inflammatory cytokines were measured, and the molecular mechanisms were evaluated using western blot. Another separation experiment used IRAK-M knockout mice and peroxisome proliferator-activated receptor-gamma (PPARγ) inhibitor to deduce the molecular mechanisms. Results: Pretreatment with allicin prior to hepatic I/R injury reduced liver damage by inhibiting aminotransferase activity and alleviating liver injury. It significantly decreased cell apoptosis, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) production, and hepatic oxidative stress. Furthermore, this study demonstrated that GW9662 (inhibitor of PPARγ) abrogated allicin's positive effect by inhibiting PPARγ expression while suppressing IRAK-M expression. Thus, the depletion of IRAK-M cannot influence the expression of PPARγ. The down-regulation of PPARγ-IRAK-M disabled the protection of allicin in I/R injury. Conclusion: Allicin protects against hepatic I/R injury via dose-dependent regulation of the PPARγ-IRAK-M-TLR4 signaling pathway, and it may be a potential drug in future clinical treatment.

Morphine promotes migration and lung metastasis of mouse melanoma cells

BACKGROUND

Morphine is an analgesic agent used for cancer pain management. There have been recent concerns that the immunosuppressant properties of morphine can also promote cancer metastasis. Morphine is an agonist for toll like receptor 4 (TLR4) that has a dual role in cancer development. The promotor or inhibitor role of morphine in cancer progression remains controversial. We investigated the effects of morphine on migration and metastasis of melanoma cells through TLR4 activation.

METHODS

Mouse melanoma cells (B16F10) were treated with only morphine (0, 0.1, 1, and 10 μM) or in combination with a TLR4 inhibitor (morphine10 μM +CLI-095 1μM) for either 12 or 24 hours. Migration of cells was analyzed by transwell migration assays. Twenty C57BL/6 male mice were inoculated with B16F10 cells via the left ventricle of the heart and then randomly divided into two groups (n = 10 each) that received either morphine (10 mg.kg^-1, sub-q) or PBS injection for 21 days (control group). Animals were euthanized and their lungs removed for evaluation of metastatic nodules.

RESULTS

Morphine (0.1, 1, and 10 μM) increased cell migration after 12 hours (p < 0.001) and after 24 hours of treatment with morphine (10 μM) (p < 0.001). Treatment with CLI-095 suppressed migration compared to cells treated with morphine alone (p < 0.001). Metastatic nodules in the morphine-treated group (64 nodules) were significantly higher than in the control group (40 nodules) (p < 0.05).

CONCLUSION

Morphine increases the migration and metastasis of mouse melanoma cells by activating TLR4.

Going, Toll-like receptors in skin inflammation and inflammatory diseases

The Indian Ayurvedic physicians knew the concept of inflammation dating back to 1500 BC. The continuous progress in the immunology of inflammation has explained its undiscovered mechanisms. For example, the discovery of Toll-like receptor 4 (TLR4) in humans (1997) has revolutionized the field of infection biology and innate immunity. The laboratory mice have shown twelve TLRs and express TLR10 (CD290) as a disrupted pseudogene, and humans have ten functional TLRs. Now, it is well established that TLRs play a significant role in different infectious and inflammatory diseases. Skin inflammation and other associated inflammatory diseases, including atopic dermatitis (AD), acne vulgaris, and psoriasis, along with many skin cancers are major health problems all over the world. The continuous development in the immunopathogenesis of inflammatory skin diseases has opened the window of opportunity for TLRs in studying their role. Hence, the manuscript explores the role of different TLRs in the pathogenesis of skin inflammation and associated inflammatory diseases. The article starts with the concept of inflammation, its origin, and the impact of TLRs discovery on infection and inflammation biology. The subsequent section describes the burden of skin-associated inflammatory diseases worldwide and the effect of the geographical habitat of people affecting it. The third section explains skin as an immune organ and explains the expression of different TLRs on different skin cells, including keratinocytes, Langerhans cells (LCs), skin fibroblasts, and melanocytes. The fourth section describes the impact of TLRs on these cells in different skin-inflammatory conditions, including acne vulgaris, AD, psoriasis, and skin cancers. The article also discusses the use of different TLR-based therapeutic approaches as specific to these inflammatory skin diseases.

Age-related transcriptome changes in melanoma patients with tumor-positive sentinel lymph nodes

Age is an important factor for determining the outcome of melanoma patients. Sentinel lymph node (SLN) status is also a strong predictor of survival for melanoma. Paradoxically, older melanoma patients have a lower incidence of SLN metastasis but a higher mortality rate when compared with their younger counterparts. The mechanisms that underlie this phenomenon remain unknown. This study uses three independent datasets of RNA samples from patients with melanoma metastatic to the SLN to identify age-related transcriptome changes in SLNs and their association with outcome. Microarray was applied to the first dataset of 97 melanoma patients. NanoString was performed in the second dataset to identify the specific immune genes and pathways that are associated with recurrence in younger versus older patients. qRT-PCR analysis was used in the third dataset of 36 samples to validate the differentially expressed genes (DEGs) from microarray and NanoString. These analyses show that FOS, NR4A, and ITGB1 genes were significantly higher in older melanoma patients with positive SLNs. IRAK3- and Wnt10b-related genes are the major pathways associated with recurrent melanoma in younger and older patients with tumor-positive SLNs, respectively. This study aims to elucidate age-related differences in SLNs in the presence of nodal metastasis.

Targeting Lipid Peroxidation for Cancer Treatment

Cancer is one of the highest prevalent diseases in humans. The chances of surviving cancer and its prognosis are very dependent on the affected tissue, body location, and stage at which the disease is diagnosed. Researchers and pharmaceutical companies worldwide are pursuing many attempts to look for compounds to treat this malignancy. Most of the current strategies to fight cancer implicate the use of compounds acting on DNA damage checkpoints, non-receptor tyrosine kinases activities, regulators of the hedgehog signaling pathways, and metabolic adaptations placed in cancer. In the last decade, the finding of a lipid peroxidation increase linked to 15-lipoxygenases isoform 1 (15-LOX-1) activity stimulation has been found in specific successful treatments against cancer. This discovery contrasts with the production of other lipid oxidation signatures generated by stimulation of other lipoxygenases such as 5-LOX and 12-LOX, and cyclooxygenase (COX-2) activities, which have been suggested as cancer biomarkers and which inhibitors present anti-tumoral and antiproliferative activities. These findings support the previously proposed role of lipid hydroperoxides and their metabolites as cancer cell mediators. Depletion or promotion of lipid peroxidation is generally related to a specific production source associated with a cancer stage or tissue in which cancer originates. This review highlights the potential therapeutical use of chemical derivatives to stimulate or block specific cellular routes to generate lipid hydroperoxides to treat this disease.

NADPH Oxidase Inhibition in Fibrotic Pathologies

Significance: Fibrosis is a stereotypic, multicellular tissue response to diverse types of injuries that fundamentally result from a failure of cell/tissue regeneration. This complex tissue remodeling response disrupts cellular/matrix composition and homeostatic cell-cell interactions, leading to loss of normal tissue architecture and progressive loss of organ structure/function. Fibrosis is a common feature of chronic diseases that may affect the lung, kidney, liver, and heart. Recent Advances: There is emerging evidence to support a combination of genetic, environmental, and age-related risk factors contributing to susceptibility and/or progression of fibrosis in different organ systems. A core pathway in fibrogenesis involving these organs is the induction and activation of nicotinamide adenine dinucleotide phosphate oxidase (NOX) family enzymes. Critical Issues: We explore current pharmaceutical approaches to targeting NOX enzymes, including repurposing of currently U.S. Food and Drug Administration (FDA)-approved drugs. Specific inhibitors of various NOX homologs will aid establishing roles of NOXs in the various organ fibroses and potential efficacy to impede/halt disease progression. Future Directions: The discovery of novel and highly specific NOX inhibitors will provide opportunities to develop NOX inhibitors for treatment of fibrotic pathologies.

Important players in carcinogenesis as potential targets in cancer therapy: an update

The development of cancer is a problem that has accompanied mankind for years. The growing number of cases, emerging drug resistance, and the need to reduce the serious side effects of pharmacotherapy are forcing scientists to better understand the complex mechanisms responsible for the initiation, promotion, and progression of the disease. This paper discusses the modulation of the particular stages of carcinogenesis by selected physiological factors, including: acetylcholine (ACh), peroxisome proliferator-activated receptors (PPAR), fatty acid-binding proteins (FABPs), Bruton's tyrosine kinase (Btk), aquaporins (AQPs), insulin-like growth factor-2 (IGF-2), and exosomes. Understanding their role may contribute to the development of more effective and safer therapies based on new binding sites.