Melatonin enhances radiofrequency-induced NK antitumor immunity, causing cancer metabolism reprogramming and inhibition of multiple pulmonary tumor development

Function of intramitochondrial melatonin and its association with Warburg metabolism

Warburg metabolism (aerobic glycolysis) is accompanied by high mitochondrial reactive oxygen species (ROS) generation from the electron transport chain; this is a "Hallmark of Cancer". The elevated ROS sustain the growth and proliferation of the cancer cells. Melatonin is a potent and functionally diverse free radical scavenger and antioxidant that is synthesized in the mitochondria of non-pathological cells and normally aids in keeping mitochondrial ROS levels low and in maintaining redox homeostasis. Because the glucose metabolite, pyruvate, does not enter mitochondria of Warburg metabolizing cells due to the inhibition of pyruvate dehydrogenase complex (PDH), acetyl coenzyme A production is diminished. Acetyl coenzyme A is a necessary co-substrate with serotonin for melatonin synthesis; thus, intramitochondrial melatonin levels become reduced in cancer cells. The hypothesis is that the depressed melatonin levels initiate aerobic glycolysis and allow the exaggerated ROS concentrations to go uncontested; the authors speculate that the elevated mtROS upregulates hypoxia inducible factor 1α (HIF-1α)/pyruvate dehydrogenase kinase (PDK) axis which inhibits PDH, thereby supporting cancer cell proliferation and stimulating cancer biomass. Exposing Warburg metabolizing cancer cells to melatonin elevates intramitochondrial melatonin, thereby reducing mtROS and concurrently interrupting aerobic glycolysis and inhibiting tumor cell proliferation. Mechanistically, higher mitochondrial melatonin levels by supplementation directly upregulates the sirtuin 3 (SIRT3)/FOXO/PDH axis, allowing pyruvate entry into mitochondria and enhancing intrinsic mitochondrial melatonin production as in non-pathological cells. Additionally, melatonin inhibits HIF1α, thereby decreasing PDK activity and disinhibiting PDH, so pyruvate enters mitochondria and is metabolized to acetyl coenzyme A, resulting in reversal of Warburg metabolism.

Microwave ablation combined with α-PD-L1 enhances abscopal effect and promotes CTL activation and intratumoral homing by a cytokine network involving IFN-γ and CXCL9

BACKGROUND AND PURPOSE

Microwave ablation (MWA) has demonstrated promising potential in instigating an anti-tumor immune response, potentially resulting in the regression of distant tumors. Nevertheless, the observed abscopal effect remains modest, and its underlying mechanism remains poorly elucidated. This study aims to systematically examine the utilization of α-PD-L1 to enhance the abscopal effect induced by MWA and to comprehensively investigate the associated mechanisms.

METHODS

The Lewis lung cancer model was employed to investigate the abscopal effect of MWA and α-PD-L1 co-treatment. The maturation status of bone marrow-derived dendritic cells (BMDCs) was observed after stimulating with the fragments of tumor cells harvested by microwave treatment. Flow cytometry analysis was employed to scrutinize the ratio of T cells and dendritic cells, along with the quantification of IFN-γ and GzmB expression levels. The expression of CXCL9 or PD-L1 was detected by immunofluorescence.

RESULTS

Local MWA treatment on one site of tumor did not yield a significant reduction in the volume of distant tumors. However, when combined with intraperitoneal α-PD-L1 injection, a notable abscopal effect was induced, resulting in decreased distant tumor volume and prolonged survival in mice. Flow cytometry analysis revealed an increase in infiltrating and activated CD8+ T cells in distant tumors, with up-regulation of IFN-γ and GzmB expression. Notably, the expression of CXCR3 was increased in CD8+ T cells. The mRNA and protein levels of CXCL9 were elevated within distant tumors, concomitant with increased infiltration of macrophages. Moreover, dendritic cells (DCs) in tumor-draining lymph nodes (TDLNs) exhibited enhanced maturation. Additionally, in vitro experiments showed enhanced maturation of BMDCs following stimulation with fragments of Lewis cells harvested via microwave treatment.

CONCLUSIONS

MWA exhibited the potential to stimulate systemic immune responses, it did not lead to a significant abscopal effect. However, the combination of MWA with α-PD-L1 treatment effectively induced the occurrence of the abscopal effect. This phenomenon appears to be linked to the activation of cytotoxic T lymphocytes (CTLs), phagocytosis by macrophages, and the maturation of DCs, facilitated by a cytokine network involving IFN-γ and CXCL9.

Interventional oncology and immunotherapy: current status and future perspectives

Interventional oncology has become an important part of multidisciplinary cancer treatment following the development of interventional radiology. Tumors can release antigens, activate immunity, and cause an abscopal effect after interventional therapy. However, the activated immune response is limited and involves a complex process. New methods to solve the problems were developed following the advent of immunotherapy. The combination therapies enhanced the antitumor immune response and improved patient outcomes with good application prospects. In this review, we have summarized the interventional therapies used to improve immune efficacy and discussed the advancements in combining interventional therapy and immunotherapy.

Melatonin ameliorates Slc26a2-associated chondrodysplasias by attenuating endoplasmic reticulum stress and apoptosis of chondrocytes

Although the pathogenesis and mechanism of congenital skeletal dysplasia are better understood, progress in drug development and intervention research remains limited. Here we report that melatonin treatment elicits a mitigating effect on skeletal abnormalities caused by SLC26A2 deficiency. In addition to our previous finding of endoplasmic reticulum stress upon SLC26A2 deficiency, we found calcium (Ca2+) overload jointly contributed to SLC26A2-associated chondrodysplasias. Continuous endoplasmic reticulum stress and cytosolic Ca2+ overload in turn triggered apoptosis of growth plate chondrocytes. Melatonin, known for its anti-oxidant and anti-inflammatory properties, emerged as a promising therapeutic approach in our study, which enhanced survival, proliferation, and maturation of chondrocytes by attenuating endoplasmic reticulum stress and Ca2+ overload. Our findings not only demonstrated the efficacy of melatonin in ameliorating abnormal function and cell fate of SLC26A2-deficient chondrocytes in vitro but also underscored its role in partially alleviating the skeletal dysplasia seen in Col2a1-CreER T2 ; Slc26a2 fl/fl mice. As revealed by histology and micro-CT analyses, melatonin significantly improved retarded cartilage growth, defective trabecular bone formation, and tibial genu varum in vivo. Collectively, these data shed translational insights for drug development and support melatonin as a potential treatment for SLC26A2-related chondrodysplasias.

Epigenomic Echoes-Decoding Genomic and Epigenetic Instability to Distinguish Lung Cancer Types and Predict Relapse

Genomic and epigenomic instability are defining features of cancer, driving tumor progression, heterogeneity, and therapeutic resistance. Central to this process are epigenetic echoes, persistent and dynamic modifications in DNA methylation, histone modifications, non-coding RNA regulation, and chromatin remodeling that mirror underlying genomic chaos and actively influence cancer cell behavior. This review delves into the complex relationship between genomic instability and these epigenetic echoes, illustrating how they collectively shape the cancer genome, affect DNA repair mechanisms, and contribute to tumor evolution. However, the dynamic, context-dependent nature of epigenetic changes presents scientific and ethical challenges, particularly concerning privacy and clinical applicability. Focusing on lung cancer, we examine how specific epigenetic patterns function as biomarkers for distinguishing cancer subtypes and monitoring disease progression and relapse.

Melatonin from Plants: Going Beyond Traditional Central Nervous System Targeting-A Comprehensive Review of Its Unusual Health Benefits

Melatonin is indispensable for the homeostasis of plants and animals. In humans, it can help prevent or be an adjuvant treatment for several diseases mainly related to the immune system, inflammation, and oxidative stress. Moreover, a melatonin-rich diet is linked to several health benefits, such as regulation of circadian rhythm, regulation of the immunological system, epilepsy control, delaying the aging process, and diminishing hormones related to cancer. This review aimed to show the effects of melatonin in diseases beyond its traditional use. The results showed it can present scavenging of free radicals, reducing inflammatory cytokines, and modulating the immune system. Moreover, it can improve insulin resistance, blood pressure, LDL-c, adipose tissue mass, adhesion molecules, endothelial impairment, and plaque formation. These effects result in neuro- and cardioprotection, improvement of liver diseases, rheumatoid arthritis, dermatitis, COVID-19, polycystic ovaries, and sepsis. We conclude that plant melatonin can benefit patients with many diseases besides sleep problems and neurodegeneration. Plant melatonin may be more cost-effective and present fewer adverse events than synthetic. However, more clinical trials should be performed to show adequate doses, formulation, and treatment time.

MELK prevents radiofrequency ablation-induced immunogenic cell death and antitumor immune response by stabilizing FABP5 in hepatocellular malignancies

BACKGROUND

Radiofrequency ablation (RFA) is an efficient treatment with unlimited potential for liver cancer that can effectively reduce patient mortality. Understanding the biological process related with RFA treatment is important for improving treatment strategy. This study aimed to identify the critical targets for regulating the efficacy of RFA.

METHODS

The RFA treatment in hepatocellular carcinoma (HCC) tumor models in vivo, was analyzed by RNA sequencing technology. The heat treatment in vitro for HCC tumor cells was also constructed to explore the mechanism after RFA treatment in tumor cells. Nanoparticles with high affinity to tumor cells were applied as a new therapy to interfere with the expression of maternal embryonic leucine zipper kinase (MELK).

RESULTS

It was found that RFA treatment upregulated MELK expression, and MELK inhibition promoted RFA efficacy by immunogenic cell death and the antitumor response, including anti-tumoral macrophage polarization and increased CD8+ T cell cytotoxicity in HCC. Mechanically, MELK binds to fatty acid-binding protein 5 (FABP5), and affects its ubiquitination through the K48R pathway to increase its stability, thereby activating protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling axis to weaken the RFA-mediated antitumor effect. In addition, the synthesis of arginylglycylaspartic acid (RGD)-lipid nanoparticles (LNPs) targeting tumor cell-intrinsic MELK enhanced RFA efficacy in HCC.

CONCLUSION

MELK is a therapeutic target by regulating RFA efficacy in HCC, and targeting MELK via RGD-LNPs provides new insight into improving RFA efficacy in HCC clinical treatment and combating the malignant progression of liver cancer.

AXL: shapers of tumor progression and immunosuppressive microenvironments

As research progresses, our understanding of the tumor microenvironment (TME) has undergone profound changes. The TME evolves with the developmental stages of cancer and the implementation of therapeutic interventions, transitioning from an immune-promoting to an immunosuppressive microenvironment. Consequently, we focus intently on the significant role of the TME in tumor proliferation, metastasis, and the development of drug resistance. AXL is highly associated with tumor progression; however, previous studies on AXL have been limited to its impact on the biological behavior of cancer cells. An increasing body of research now demonstrates that AXL can influence the function and differentiation of immune cells, mediating immune suppression and thereby fostering tumor growth. A comprehensive analysis to identify and overcome the causes of immunosuppressive microenvironments represents a novel approach to conquering cancer. In this review, we focus on elucidating the role of AXL within the immunosuppressive microenvironments, discussing and analyzing the effects of AXL on tumor cells, T cells, macrophages, natural killer (NK) cells, fibroblasts, and other immune-stromal cells. We aim to clarify the contributions of AXL to the progression and drug resistance of cancer from its functional role in the immune microenvironment.

Dysfunctional mitochondria in age-related neurodegeneration: Utility of melatonin as an antioxidant treatment

Mitochondria functionally degrade as neurons age. Degenerative changes cause inefficient oxidative phosphorylation (OXPHOS) and elevated electron leakage from the electron transport chain (ETC) promoting increased intramitochondrial generation of damaging reactive oxygen and reactive nitrogen species (ROS and RNS). The associated progressive accumulation of molecular damage causes an increasingly rapid decline in mitochondrial physiology contributing to aging. Melatonin, a multifunctional free radical scavenger and indirect antioxidant, is synthesized in the mitochondrial matrix of neurons. Melatonin reduces electron leakage from the ETC and elevates ATP production; it also detoxifies ROS/RNS and via the SIRT3/FOXO pathway it upregulates activities of superoxide dismutase 2 and glutathione peroxidase. Melatonin also influences glucose processing by neurons. In neurogenerative diseases, neurons often adopt Warburg-type metabolism which excludes pyruvate from the mitochondria causing reduced intramitochondrial acetyl coenzyme A production. Acetyl coenzyme A supports the citric acid cycle and OXPHOS. Additionally, acetyl coenzyme A is a required co-substrate for arylalkylamine-N-acetyl transferase, which rate limits melatonin synthesis; therefore, melatonin production is diminished in cells that experience Warburg-type metabolism making mitochondria more vulnerable to oxidative stress. Moreover, endogenously produced melatonin diminishes during aging, further increasing oxidative damage to mitochondrial components. More normal mitochondrial physiology is preserved in aging neurons with melatonin supplementation.

Melatonin increases Olaparib sensitivity and suppresses cancer-associated fibroblast infiltration via suppressing the LAMB3-CXCL2 axis in TNBC

Triple-negative breast cancer (TNBC) is the most malignant breast cancer subtype, characterized with high aggressiveness and a high recurrence rate. Olaparib is the first US Food and Drug Administration-approved poly(ADP ribose) polymerase (PARP) inhibitor (PARPi) to treat breast cancer patients with a germline BRCA1 or BRCA2 mutation. However, resistance to Olaparib treatment restricts the therapeutic effects, and thus novel therapeutics are urgently required. In the present study, we identified that the combination of melatonin and Olaparib synergistically enhanced the sensitivity of TNBC cells. Moreover, melatonin exerted promising antitumor activities in Olaparib-resistant cells, implying the potential for its clinical application. An RNA-sequencing analysis revealed that melatonin treatment downregulated laminin subunit beta 3 (LAMB3) expression. Genetic ablation of LAMB3 significantly increased Olaparib sensitivity, and subsequently suppressed proliferation, epithelial-to-mesenchymal transition (EMT)-related gene expressions, and aggressiveness of breast cancer cells. Accordingly, LAMB3 expression was positively correlated with C-X-C motif chemokine ligand 2 (CXCL2), and they collaboratively promoted cancer-associated fibroblast (CAF) infiltration. An in vivo study demonstrated that combined treatment with melatonin and Olaparib showed enhanced inhibitory efficacy against tumor growth, LAMB3 expression, CXCL2 levels, and CAF infiltration compared to single treatment groups, and combined treatment with melatonin and Olaparib significantly ameliorated the immunosuppressive tumor microenvironment. These findings illustrate a promising therapeutic strategy using melatonin to overcome Olaparib resistance and activate antitumor immunity via attenuating the LAMB3-CXCL2 axis in breast cancer patients.

Beyond Cancer Cells: How the Tumor Microenvironment Drives Cancer Progression

Liver cancer represents a substantial global health challenge, contributing significantly to worldwide morbidity and mortality. It has long been understood that tumors are not composed solely of cancerous cells, but also include a variety of normal cells within their structure. These tumor-associated normal cells encompass vascular endothelial cells, fibroblasts, and various inflammatory cells, including neutrophils, monocytes, macrophages, mast cells, eosinophils, and lymphocytes. Additionally, tumor cells engage in complex interactions with stromal cells and elements of the extracellular matrix (ECM). Initially, the components of what is now known as the tumor microenvironment (TME) were thought to be passive bystanders in the processes of tumor proliferation and local invasion. However, recent research has significantly advanced our understanding of the TME's active role in tumor growth and metastasis. Tumor progression is now known to be driven by an intricate imbalance of positive and negative regulatory signals, primarily influenced by specific growth factors produced by both inflammatory and neoplastic cells. This review article explores the latest developments and future directions in understanding how the TME modulates liver cancer, with the aim of informing the design of novel therapies that target critical components of the TME.

Radiofrequency ablation: mechanisms and clinical applications

Radiofrequency ablation (RFA), a form of thermal ablation, employs localized heat to induce protein denaturation in tissue cells, resulting in cell death. It has emerged as a viable treatment option for patients who are ineligible for surgery in various diseases, particularly liver cancer and other tumor-related conditions. In addition to directly eliminating tumor cells, RFA also induces alterations in the infiltrating cells within the tumor microenvironment (TME), which can significantly impact treatment outcomes. Moreover, incomplete RFA (iRFA) may lead to tumor recurrence and metastasis. The current challenge is to enhance the efficacy of RFA by elucidating its underlying mechanisms. This review discusses the clinical applications of RFA in treating various diseases and the mechanisms that contribute to the survival and invasion of tumor cells following iRFA, including the roles of heat shock proteins, hypoxia, and autophagy. Additionally, we analyze‌ the changes occurring in infiltrating cells within the TME after iRFA. Finally, we provide a comprehensive summary of clinical trials involving RFA in conjunction with other treatment modalities in the field of cancer therapy, aiming to offer novel insights and references for improving the effectiveness of RFA.

Emerging role of sirtuins in non‑small cell lung cancer (Review)

Non‑small cell lung cancer (NSCLC) is a highly prevalent lung malignancy characterized by insidious onset, rapid progression and advanced stage at the time of diagnosis, making radical surgery impossible. Sirtuin (SIRT) is a histone deacetylase that relies on NAD+ for its function, regulating the aging process through modifications in protein activity and stability. It is intricately linked to various processes, including glycolipid metabolism, inflammation, lifespan regulation, tumor formation and stress response. An increasing number of studies indicate that SIRTs significantly contribute to the progression of NSCLC by regulating pathophysiological processes such as energy metabolism, autophagy and apoptosis in tumor cells through the deacetylation of histones or non‑histone proteins. The present review elaborates on the roles of different SIRTs and their mechanisms in NSCLC, while also summarizing novel therapeutic agents based on SIRTs. It aims to present new ideas and a theoretical basis for NSCLC treatment.

Master regulator: p53's pivotal role in steering NK-cell tumor patrol

The p53 protein, encoded by TP53, is a tumor suppressor that plays a critical role in regulating apoptosis, cell cycle regulation, and angiogenesis in tumor cells via controlling various downstream signals. Natural killer (NK) cell-mediated immune surveillance is a vital self-defense mechanism against cancer and other diseases, with NK cell activity regulated by various mechanisms. Among these, p53 plays a significant role in immune regulation by maintaining the homeostasis and functionality of NK cells. It enhances the transcriptional activity of NK cell-activating ligands and downregulates inhibitory ligands to boost NK cell activation and tumor-killing efficacy. Additionally, p53 influences NK cell cytotoxicity by promoting apoptosis, autophagy, and ferroptosis in different tumor cells. p53 is involved in the regulation of NK cell activity and effector functions through multiple pathways. p53 also plays a pivotal role in the tumor microenvironment (TME), regulating the activity of NK cells. NK cells are critical components of the TME and are capable of directly killing tumor cells. And p53 mutates in numerous cancers, with the most common alteration being a missense mutation. These mutations are commonly associated with poor survival rates in patients with cancer. This review details p53's role in NK cell tumor immunosurveillance, summarizing how p53 enhances NK cell recognition and tumor destruction. We also explore the potential applications of p53 in tumor immunotherapy, discussing strategies for modulating p53 to enhance NK cell function and improve the efficacy of tumor immunotherapy, along with the associated challenges. Understanding the interaction between p53 and NK cells within the TME is crucial for advancing NK cell-based immunotherapy and developing p53-related novel therapeutics.

GPRC5A promotes paclitaxel resistance and glucose content in NSCLC

Lung cancer is one of the most common and malignant cancers worldwide. Chemotherapy has been widely used in the clinical setting, and paclitaxel is the first-line therapy for lung cancer patients but paclitaxel resistance is the main problem. First, we successfully established paclitaxel-resistant lung cancer cells treated with elevated doses of paclitaxel for 3 months, as confirmed by the CCK-8 assay. Paclitaxel-resistant cancer cells increased glucose content. Second, Gtex, Oncomine, and gene expression omnibus database data mining identified GPRC5A, G protein-coupled receptor, as the most prominent differentially expressed gene in drug-resistant datasets including gemcitabine, paclitaxel, and gefitinib overlapped with the microarray data from cancer cell metabolism. Third, qPCR analysis and western blot technique showed that GPRC5A mRNA and protein levels were significantly enhanced in paclitaxel-resistant lung cancer cells. Fourth, functional analysis was conducted by siRNA-mediated transient knockdown of GPRC5A. Silencing GPRC5A significantly decreased paclitaxel resistance and glucose content. In the end, retinoic acid substantially upregulated GPRC5A proteins and promoted glucose content in two lung cancer cells. Kaplan-Meier plot also confirmed that lung cancer patients with high expression of GPRC5A had a relatively lower survival rate. Our study provided a potential drug target GPRC5A, which may benefit lung cancer patients with acquired paclitaxel resistance in the future and a theoretical basis for future preclinical trials.

In Vitro and In Vivo Effects of Melatonin-Containing Combinations in Human Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has poor prognosis and high mortality rates. Therefore, it is necessary to identify new targets and therapeutic strategies to improve the prognosis of patients with PDAC. Integrative therapies are increasingly being used to boost the efficacy of the known anticancer therapeutic approaches. Hence, this study aimed to evaluate the effects of a novel combination of different potential anticancer molecules, melatonin (MLT), cannabidiol (CBD), and oxygen-ozone (O2/O3) to treat PDAC using in vitro and in vivo models of human PDAC. The effect of this combination was investigated in combination with gemcitabine (GEM), the most common chemotherapeutic drug used for PDAC treatment. The combination of MLT + CBD + O2/O3 was more effective than the individual treatments in inhibiting PDAC cell viability and proliferation, inducing cell death, and modulating the RAS pathway protein levels. Moreover, different combinations of treatments reduced tumor mass in the PDAC mouse model, thus promoting the effect of GEM. In conclusion, a mixture of MLT + CBD + O2/O3 could serve as a potential adjuvant therapeutic strategy for PDAC.

Melatonin alleviates high-fat-diet-induced dry eye by regulating macrophage polarization via IFT27 and lowering ERK/JNK phosphorylation

Dry eye disease is the most common ocular surface disease globally, requiring a more effective treatment. We observed that a high-fat diet induced macrophage polarization to M1 and further induced inflammation in the meibomian and lacrimal glands. A four-week treatment with melatonin (MLT) eye drops can regulate macrophage polarization and alleviate dry eye signs. To investigate the therapeutic effects and mechanisms of action of MLT on high-fat-diet-induced dry eye disease in mice, RAW 264.7 cells pretreated with LPS and/or MLT underwent digital RNA with the perturbation of genes sequencing (DRUG-seq). Results showed that IFT27 was up-regulated, and MAPK pathways were suppressed after MLT pre-treatment. ERK/JNK phosphorylation was reduced in meibomian glands of MLT-treated dry eye mice and increased in IFT27 knockdown RAW 264.7 cells. In summary, MLT regulated macrophage polarization via IFT27 and reduced ERK/JNK phosphorylation. These results support that MLT is a promising medication for dry eye disease.

Radiofrequency radiation reshapes tumor immune microenvironment into antitumor phenotype in pulmonary metastatic melanoma by inducing active transformation of tumor-infiltrating CD8+ T and NK cells

Immunosuppression by the tumor microenvironment is a pivotal factor contributing to tumor progression and immunotherapy resistance. Priming the tumor immune microenvironment (TIME) has emerged as a promising strategy for improving the efficacy of cancer immunotherapy. In this study we investigated the effects of noninvasive radiofrequency radiation (RFR) exposure on tumor progression and TIME phenotype, as well as the antitumor potential of PD-1 blockage in a model of pulmonary metastatic melanoma (PMM). Mouse model of PMM was established by tail vein injection of B16F10 cells. From day 3 after injection, the mice were exposed to RFR at an average specific absorption rate of 9.7 W/kg for 1 h per day for 14 days. After RFR exposure, lung tissues were harvested and RNAs were extracted for transcriptome sequencing; PMM-infiltrating immune cells were isolated for single-cell RNA-seq analysis. We showed that RFR exposure significantly impeded PMM progression accompanied by remodeled TIME of PMM via altering the proportion and transcription profile of tumor-infiltrating immune cells. RFR exposure increased the activation and cytotoxicity signatures of tumor-infiltrating CD8+ T cells, particularly in the early activation subset with upregulated genes associated with T cell cytotoxicity. The PD-1 checkpoint pathway was upregulated by RFR exposure in CD8+ T cells. RFR exposure also augmented NK cell subsets with increased cytotoxic characteristics in PMM. RFR exposure enhanced the effector function of tumor-infiltrating CD8+ T cells and NK cells, evidenced by increased expression of cytotoxic molecules. RFR-induced inhibition of PMM growth was mediated by RFR-activated CD8+ T cells and NK cells. We conclude that noninvasive RFR exposure induces antitumor remodeling of the TIME, leading to inhibition of tumor progression, which provides a promising novel strategy for TIME priming and potential combination with cancer immunotherapy.

Cancer energy reprogramming and the immune responses

Cancer as an uncontrolled growth of cells due to existing mutation in host cells that may proliferate, induce angiogenesis and sometimes metastasize due to the favorable tumor microenvironment (TME). Since it kills more than any disease, biomedical science does not relent in studying the exact pathogenesis. It was believed to be a problem that lies in the nucleus of the host cells; however, recent oncology findings are shifting attention to the mitochondria as an adjuvant to cancer pathogenesis. The changes in the gene are strongly related to cellular metabolism and metabolic reprogramming. It is now understood that reprogramming the TME will have a direct effect on the immune cells' metabolism. Although there are a number of studies on immune cells' response towards tumor energy reprogramming and cancer progression, there is still no existence with the updated collation of these immune cells' response to distinct energy reprogramming in cancer studies. To this end, this mini review shed some light on cancer energy reprogramming mechanisms and enzyme degradation pathways, the cancer pathogenicity activity series involved with reduced lactate production, the specific immune cell responses due to the energy reprogramming. This study highlighted some prospects and future experiments in harnessing the host immune response towards the altered energy metabolism due to cancer.

From Androgen Dependence to Independence in Prostate Cancer: Unraveling Therapeutic Potential and Proteomic Landscape of Hydroxychloroquine as an Autophagy Inhibitor

Prostate cancer is a major planetary health challenge wherein new ways of thinking drug discovery and therapeutics innovation are much needed. Numerous studies have shown that autophagy inhibition holds a significant role as an adjunctive intervention in prostate cancer. Hydroxychloroquine (HCQ) has gained considerable attention due to its established role as an autophagy inhibitor across diverse cancer types, but its proteomics landscape and systems biology in prostate cancer are currently lacking in the literature. This study reports the proteomic responses to HCQ in prostate cancer cells, namely, androgen-dependent LNCaP and androgen-independent PC3 cells. Differentially expressed proteins and proteome in HCQ-treated cells were determined by label-free quantification with nano-high-performance liquid chromatography and tandem mass spectrometry (nHPLC-MS/MS), and harnessing bioinformatics tools. In PC3 cells, there was a marked shift toward metabolic reprogramming, highlighted by an upregulation of mitochondrial proteins in oxidative phosphorylation and tricarboxylic acid cycle, suggesting an adaptive mechanism to maintain energy production under therapeutic stress. In contrast, LNCaP cells prioritized proteostasis and cell cycle regulation, indicating a more conservative adaptation strategy. To the best of our knowledge, this study is the first to demonstrate the differential responses of prostate cancer cells to autophagy inhibition by HCQ, suggesting that a combination therapy approach, targeting distinct pathways in androgen-independent and androgen-dependent cells, could represent a promising treatment strategy. Moreover, the varied proteomic responses observed between these cell lines underscore the importance of personalized medicine in cancer therapy. Future translational and clinical research on HCQ and prostate cancer are called for.

Mechanism of Action of Melatonin as a Potential Adjuvant Therapy in Inflammatory Bowel Disease and Colorectal Cancer

Inflammatory bowel disease (IBD), a continuum of chronic inflammatory diseases, is tightly associated with immune system dysregulation and dysbiosis, leading to inflammation in the gastrointestinal tract (GIT) and multiple extraintestinal manifestations. The pathogenesis of IBD is not completely elucidated. However, it is associated with an increased risk of colorectal cancer (CRC), which is one of the most common gastrointestinal malignancies. In both IBD and CRC, a complex interplay occurs between the immune system and gut microbiota (GM), leading to the alteration in GM composition. Melatonin, a neuroendocrine hormone, was found to be involved with this interplay, especially since it is present in high amounts in the gut, leading to some protective effects. Actually, melatonin enhances the integrity of the intestinal mucosal barrier, regulates the immune response, alleviates inflammation, and attenuates oxidative stress. Thereby, the authors summarize the multifactorial interaction of melatonin with IBD and with CRC, focusing on new findings related to the mechanisms of action of this hormone, in addition to its documented positive outcomes on the treatment of these two pathologies and possible future perspectives to use melatonin as an adjuvant therapy.

Potential of Thermal Ablation Combined with Immunotherapy in Peripheral Lung Tumors: A Review and Prospect

BACKGROUND

Lung tumors are prevalent malignancies associated with a high mortality rate, imposing significant medical and societal burdens. Although immunotherapy shows promise in improving survival, response rates are relatively modest. Thermal ablation can not only eliminate tumor cells directly but also enhance antitumor immunity response, thus manifesting a remarkable propensity to synergize with immunotherapy.

SUMMARY

In this review, we provided a brief overview of the application of thermal ablation in peripheral lung tumors. We summarized the patient selection of thermal ablation. We highlighted the potential of thermal ablation to augment the antitumor immune response, offering a promising avenue for combined therapies. We summarized studies assessing the synergistic effects of thermal ablation and immunotherapy in preclinical and clinical settings. Lastly, we underscored the urgent issues that warrant in-depth exploration when applying thermal ablation and immunotherapy to lung tumor patients.

KEY MESSAGES

This review emphasized the prospects of using thermal ablation combined with immunotherapy in patients with peripheral lung tumors. However, further research is needed to enhance and optimize this treatment strategy.

Melatonin and Its Role in the Epithelial-to-Mesenchymal Transition (EMT) in Cancer

The epithelial-to-mesenchymal transition (EMT) is a cell-biological program that occurs during the progression of several physiological processes and that can also take place during pathological situations such as carcinogenesis. The EMT program consists of the sequential activation of a number of intracellular signaling pathways aimed at driving epithelial cells toward the acquisition of a series of intermediate phenotypic states arrayed along the epithelial-mesenchymal axis. These phenotypic features include changes in the motility, conformation, polarity and functionality of cancer cells, ultimately leading cells to stemness, increased invasiveness, chemo- and radioresistance and the formation of cancer metastasis. Amongst the different existing types of the EMT, type 3 is directly involved in carcinogenesis. A type 3 EMT occurs in neoplastic cells that have previously acquired genetic and epigenetic alterations, specifically affecting genes involved in promoting clonal outgrowth and invasion. Markers such as E-cadherin; N-cadherin; vimentin; and transcription factors (TFs) like Twist, Snail and ZEB are considered key molecules in the transition. The EMT process is also regulated by microRNA expression. Many miRNAs have been reported to repress EMT-TFs. Thus, Snail 1 is repressed by miR-29, miR-30a and miR-34a; miR-200b downregulates Slug; and ZEB1 and ZEB2 are repressed by miR-200 and miR-205, respectively. Occasionally, some microRNA target genes act downstream of the EMT master TFs; thus, Twist1 upregulates the levels of miR-10b. Melatonin is an endogenously produced hormone released mainly by the pineal gland. It is widely accepted that melatonin exerts oncostatic actions in a large variety of tumors, inhibiting the initiation, progression and invasion phases of tumorigenesis. The molecular mechanisms underlying these inhibitory actions are complex and involve a great number of processes. In this review, we will focus our attention on the ability of melatonin to regulate some key EMT-related markers, transcription factors and micro-RNAs, summarizing the multiple ways by which this hormone can regulate the EMT. Since melatonin has no known toxic side effects and is also known to help overcome drug resistance, it is a good candidate to be considered as an adjuvant drug to conventional cancer therapies.

Melatonin in cancer biology: pathways, derivatives, and the promise of targeted delivery

Melatonin, historically recognized for its primary role in regulating circadian rhythms, has expanded its influence particularly due to its wide range of biological activities. It has firmly established itself in cancer research. To highlight its versatility, we delved into how melatonin interacts with key signaling pathways, such as the Wnt/β-Catenin, PI3K, and NF-κB pathways, which play foundational roles in tumor development and progression. Notably, melatonin can intricately modulate these pathways, potentially affecting various cellular functions such as apoptosis, metastasis, and immunity. Additionally, a comprehensive review of current clinical studies provides a dual perspective. These studies confirm melatonin's potential in cancer management but also underscore its inherent limitations, particularly its limited bioavailability, which often relegates it to a supplementary role in treatments. Despite this limitation, there is an ongoing quest for innovative solutions and current advancements include the development of melatonin derivatives and cutting-edge delivery systems. By synthesizing the past, present, and future, this review provides a detailed overview of melatonin's evolving role in oncology, positioning it as a potential cornerstone in future cancer therapeutics.

Contribution of immune cells in synergistic anti-tumor effect of ablation and immunotherapy

Thermal ablation results in the damage of tumor tissue, which leads to localized necrosis and incites a significant inflammatory response, accompanied by the infiltration of numerous immune cells. Nevertheless, depending solely on the singular approach of thermal ablation frequently is difficult in eliciting a robust anti-tumor response. Research suggests that integrating immune modulators into conventional ablation techniques has the potential to enhance the elicited immune response, finally initiating synergistic effect without significantly elevated risk profiles. This article comprehensively analyses the immunological effects resulting from post-ablation alone and its synergy with immunotherapies, and accentuates the heterogeneous alterations noted in immune cells across distinct malignancies. Collectively, the article delves into the theoretical framework and advancements in clinical trials concerning the combined thermal ablation and immunotherapy for treating malignant tumors.

Clinical outcomes and tumor microenvironment response to radiofrequency ablation therapy: a systematic review and meta-analysis

Background

Radiofrequency ablation (RFA) utilizes minimally invasive high-energy current to precisely ablate tumor cells. It has been utilized in many cancer types including thyroid, lung, and liver cancer. It has been shown to provide adequate ablative margins with minimal complications; however, incomplete RFA may lead to recurrence of tumor. The underlying cellular mechanism and behavior of ablated cancer tissue is poorly understood.

Methods

A systematic review was performed, searching EMBASE, Web of Science, PubMed, and Scopus for studies published up to March 2022 and reported following PRISMA guidelines. Collection was performed by two groups of investigators to avoid risk of bias. The Cochrane Collaboration's tool was used for assessing risk of bias. We identified human, in vivo, and in vitro research studies utilizing RFA for tumor tissues. We required that the studies included at least one of the following: complications, recurrence, or survival, and took interest to studies identifying cellular signaling pathway patterns after RFA. Descriptive statistical analysis was performed in 'R' software including mean and confidence interval.

Results

The most frequent cancers studied were liver and lung cancers accounting for 57.4% (N=995) and 15.4% (N=267), followed by esophageal (N=190) and breast cancer (N=134). The most common reported complications were bleeding (19%) and post-operative pain (14%). In our literature search, four independent studies showed upregulation and activation of the VEGF pathway following RFA, four showed upregulation and activation of the AKT pathway following RFA, three studies demonstrated involvement of matrix metalloproteinases, and four showed upregulation of c-Met protein following RFA.

Conclusions

In our review and meta-analysis, we identify several proteins and pathways of interest of which are important in wound healing, angiogenesis, and cellular growth and survival. These proteins and pathways of interest may implicate areas of research towards RFA resistance and cancer recurrence.

From Genes to Therapy: Pituitary Adenomas in the Era of Precision Medicine

This review presents a comprehensive analysis of pituitary adenomas, a type of brain tumor with diverse behaviors and complexities. We cover various treatment approaches, including surgery, radiotherapy, chemotherapy, and their integration with newer treatments. Key to the discussion is the role of biomarkers in oncology for risk assessment, diagnosis, prognosis, and the monitoring of pituitary adenomas. We highlight advances in genomic, epigenomic, and transcriptomic analyses and their contributions to understanding the pathogenesis and molecular pathology of these tumors. Special attention is given to the molecular mechanisms, including the impact of epigenetic factors like histone modifications, DNA methylation, and transcriptomic changes on different subtypes of pituitary adenomas. The importance of the tumor immune microenvironment in tumor behavior and treatment response is thoroughly analyzed. We highlight potential breakthroughs and innovations for a more effective management and treatment of pituitary adenomas, while shedding light on the ongoing need for research and development in this field to translate scientific knowledge into clinical advancements, aiming to improve patient outcomes.

Multi-omics analysis revealed the mitochondrial-targeted drug combination to suppress the development of lung cancer

PURPOSE

The incidence and mortality of lung cancer are continuously rising in recent years. Mitochondrial energy metabolism malfunction is found to be crucial in cancer proliferation and bioenergetic reprogramming, especially for lung cancer. In this study, we attempted to use mitochondrial-targeted drug therapy to change the energy metabolism pattern of cancer cells to inhibit the development of lung cancer, and investigated its mechanism of action and key targets through multi-omics studies.

METHODS

In this study, we established the in vivo tumor mouse mode, treated mice with multiple mitochondrial-targeted drug combinations and DDP, severally. Then, we investigated the differences between the 7-drug group with the control group and the DDP treatment group by transcriptomics, proteomics and metabolomics to find the therapeutic targets.

RESULTS

We found that mitochondria-targeting drug cocktail therapy, especially the 7-drug regimen, effectively improved mitochondrial metabolism, changed energy supply patterns in lung cancer cells, significantly increased NK cells in tumor tissues, and decreased tumor markers in plasma. Multi-omics analysis informed that the combination of 7-drug could up-regulate mitochondrial oxidative phosphorylation, ATP synthesis and autophagy related genes, and down-regulate proliferation and immune-related genes compared with the control group. By further mapping the protein interaction network, we identified a key target for 7-drug therapy to reverse tumor metabolic reprogramming and validated it in metabolomics.

CONCLUSIONS

Mitochondrial-targeted drug cocktail therapy can effectively inhibit the occurrence and development of tumors, through the reprogramming of energy metabolism and the increase in immune cells in tumor tissues. Thus, we provide a novel approach for the treatment of lung cancer and present evidence-based clues for the combined use of targeted mitochondrial drugs.

Melatonin, BAG-1 and cortisol circadian interactions in tumor pathogenesis and patterned immune responses

A dysregulated circadian rhythm is significantly associated with cancer risk, as is aging. Both aging and circadian dysregulation show suppressed pineal melatonin, which is indicated in many studies to be linked to cancer risk and progression. Another independently investigated aspect of the circadian rhythm is the cortisol awakening response (CAR), which is linked to stress-associated hypothalamus-pituitary-adrenal (HPA) axis activation. CAR and HPA axis activity are primarily mediated via activation of the glucocorticoid receptor (GR), which drives patterned gene expression via binding to the promotors of glucocorticoid response element (GRE)-expressing genes. Recent data shows that the GR can be prevented from nuclear translocation by the B cell lymphoma-2 (Bcl-2)-associated athanogene 1 (BAG-1), which translocates the GR to mitochondria, where it can have diverse effects. Melatonin also suppresses GR nuclear translocation by maintaining the GR in a complex with heat shock protein 90 (Hsp90). Melatonin, directly and/or epigenetically, can upregulate BAG-1, suggesting that the dramatic 10-fold decrease in pineal melatonin from adolescence to the ninth decade of life will attenuate the capacity of night-time melatonin to modulate the effects of the early morning CAR. The interactions of pineal melatonin/BAG-1/Hsp90 with the CAR are proposed to underpin how aging and circadian dysregulation are associated with cancer risk. This may be mediated via differential effects of melatonin/BAG-1/Hsp90/GR in different cells of microenvironments across the body, from which tumors emerge. This provides a model of cancer pathogenesis that better integrates previously disparate bodies of data, including how immune cells are regulated by cancer cells in the tumor microenvironment, at least partly via the cancer cell regulation of the tryptophan-melatonin pathway. This has a number of future research and treatment implications.

Nanomedicine-based adjuvant therapy: a promising solution for lung cancer

Lung cancer has been the leading cause of cancer-related deaths worldwide for decades. Despite the increasing understanding of the underlying disease mechanisms, the prognosis still remains poor for many patients. Novel adjuvant therapies have emerged as a promising treatment method to augment conventional methods and boost the therapeutic effects of primary therapies. Adjuvant therapy based on nanomedicine has gained considerable interest for supporting and enhancing traditional therapies, such as chemotherapy, immunotherapy, and radiotherapy, due to the tunable physicochemical features and ease of synthetic design of nanomaterials. In addition, nanomedicine can provide protective effects against other therapies by reducing adverse side effects through precise disease targeting. Therefore, nanomedicine-based adjuvant therapies have been extensively employed in a wide range of preclinical and clinical cancer treatments to overcome the drawbacks of conventional therapies. In this review, we mainly discuss the recent advances in adjuvant nanomedicine for lung cancer treatment and highlight their functions in improving the therapeutic outcome of other therapies, which may inspire new ideas for advanced lung cancer therapies and stimulate research efforts around this topic.

Genetic trajectory and clonal evolution of multiple primary lung cancer with lymph node metastasis

Multiple primary lung cancer (MPLC) with lymph node metastasis (LNM) is a rare phenomenon of multifocal lung cancer. The genomic landscapes of MPLC and the clonal evolution pattern between primary lung lesions and lymph node metastasis haven't been fully illustrated. We performed whole-exome sequencing (WES) on 52 FFPE (Formalin-fixed Paraffin-Embedded) samples from 11 patients diagnosed with MPLC with LNM. Genomic profiling and phylogenetic analysis were conducted to infer the evolutional trajectory within each patient. The top 5 most frequently mutated genes in our study were TTN (76.74%), MUC16 (62.79%), MUC19 (55.81%), FRG1 (46.51%), and NBPF20 (46.51%). For most patients in our study, a substantial of genetic alterations were mutually exclusive among the multiple pulmonary tumors of the same patient, suggesting their heterogenous origins. Individually, the genetic profile of lymph node metastatic lesions overlapped with that of multiple lung cancers in different degrees but are more genetically related to specific pulmonary lesions. SETD2 was a potential metastasis biomarker of MPLC. The mean putative neo-antigen number of the primary tumor (646.5) is higher than that of lymph node metastases (300, p = 0.2416). Primary lung tumors and lymph node metastases are highly heterogenous in immune repertoires. Our findings portrayed the comprehensive genomic landscape of MPLC with LNM. We characterized the genomic heterogeneity among different tumors. We offered novel clues to the clonal evolution between MPLC and their lymphatic metastases, thus advancing the treatment strategies and preventions of MPLC with LNM.

A novel regulator in cancer initiation and progression: long noncoding RNA SHNG9

Cancer has become the most common life-threatening disease in the world. Cancers presenting with advanced stages and metastasis show poor prognosis, even with the application of radiotherapy, surgery, chemotherapy and immunotherapy. It is of great importance to explore novel, efficient biomarkers and their internal mechanisms. Recently, it has been reported that long noncoding RNAs (lncRNAs) play important roles in tumor initiation and progression, influencing downstream mRNAs by interacting with miRNAs and functioning as sponges in competing endogenous RNA (ceRNA) networks. Small nucleolar RNA host gene 9 (SNHG9) binds with miRNAs, inducing miRNA downregulation. The downregulated miRNAs enhance downstream target gene expression via ceRNA networks. Dysregulation of SNHG9 is widely observed in tumors and is associated with clinical prognosis features, which makes it a valuable target for cancer biomarkers and therapeutics. Dysregulated SNHG9 in tumor cells also functions in tumor proliferation, colony formation, migration, invasion and inhibition of apoptosis and tumor cell metabolism. This systematic review of SNHG9 in tumors provides new perspectives on cancer diagnosis and treatment.

Tumor Microenvironment and Metabolism: Role of the Mitochondrial Melatonergic Pathway in Determining Intercellular Interactions in a New Dynamic Homeostasis

There is a growing interest in the role of alterations in mitochondrial metabolism in the pathoetiology and pathophysiology of cancers, including within the array of diverse cells that can form a given tumor microenvironment. The 'exhaustion' in natural killer cells and CD8+ t cells as well as the tolerogenic nature of dendritic cells in the tumor microenvironment seems determined by variations in mitochondrial function. Recent work has highlighted the important role played by the melatonergic pathway in optimizing mitochondrial function, limiting ROS production, endogenous antioxidants upregulation and consequent impacts of mitochondrial ROS on ROS-dependent microRNAs, thereby impacting on patterned gene expression. Within the tumor microenvironment, the tumor, in a quest for survival, seeks to 'dominate' the dynamic intercellular interactions by limiting the capacity of cells to optimally function, via the regulation of their mitochondrial melatonergic pathway. One aspect of this is the tumor's upregulation of kynurenine and the activation of the aryl hydrocarbon receptor, which acts to metabolize melatonin and increase the N-acetylserotonin/melatonin ratio, with effluxed N-acetylserotonin acting as a brain-derived neurotrophic factor (BDNF) mimic via its activation of the BDNF receptor, TrkB, thereby increasing the survival and proliferation of tumors and cancer stem-like cells. This article highlights how many of the known regulators of cells in the tumor microenvironment can be downstream of the mitochondrial melatonergic pathway regulation. Future research and treatment implications are indicated.

Potential role of melatonin in prevention and treatment of lung cancer

Lung cancer is the second most common cancer and the most lethal cancer worldwide. Melatonin, an indoleamine produced in the pineal gland, shows anticancer effects on a variety of cancers, especially lung cancer. Herein, we clarify the pathophysiology of lung cancer, the association of circadian rhythm with lung, and the relationship between shift work and the incidence of lung cancer. Special focus is placed on the role of melatonin receptors in lung cancer, the relationship between inflammation and lung cancer, control of cell proliferation, apoptosis, autophagy, and immunomodulation in lung cancer by melatonin. A review of the drug synergy of melatonin with other anticancer drugs suggests its usefulness in combination therapy. In summary, the information compiled may serve as a comprehensive reference for the various mechanisms of action of melatonin against lung cancer, as a guide for the design of future experimental research and for advancing melatonin as a therapeutic agent for lung cancer.

CYP1B1: A Novel Molecular Biomarker Predicts Molecular Subtype, Tumor Microenvironment, and Immune Response in 33 Cancers

BACKGROUND

Cytochrome P450 Family 1 Subfamily B Member 1 (CYP1B1) is a critical metabolic enzyme of melatonin. Although melatonin has been identified to exhibit tumor suppressing activity, the role and mechanism of the clinical and immunological characteristics of CYP1B1 in cancer remain unclear.

METHODS

In this study, RNA expression and clinical data were obtained from The Cancer Genome Atlas (TCGA) across 33 solid tumors. The expression, survival, immune subtype, molecular subtype, tumor mutation burden (TMB), microsatellite instability (MSI), biological pathways, and function in vitro and vivo were evaluated. The predictive value of CYP1B1 in immune cohorts was further explored.

RESULTS

We found the dysregulated expression of CYP1B1 was associated with the clinical stage and tumor grade. Immunological correlation analysis showed CYP1B1 was positively correlated with the infiltration of lymphocyte, immunomodulator, chemokine, receptor, and cancer-associated fibroblasts (CAFs) in most cancer. Meanwhile, CYP1B1 was involved in immune subtype and molecular subtype, and was connected with TMB, MSI, neoantigen, the activation of multiple melatonergic and immune-related pathways, and therapeutic resistance.

CONCLUSIONS

Together, this study comprehensively revealed the role and mechanism of CYP1B1 and explored the significant association between CYP1B1 expression and immune activity. These findings provide a promising predictor and molecular target for clinical immune treatment.

Nanomaterials: small particles show huge possibilities for cancer immunotherapy

With the economy's globalization and the population's aging, cancer has become the leading cause of death in most countries. While imposing a considerable burden on society, the high morbidity and mortality rates have continuously prompted researchers to develop new oncology treatment options. Anti-tumor regimens have evolved from early single surgical treatment to combined (or not) chemoradiotherapy and then to the current stage of tumor immunotherapy. Tumor immunotherapy has undoubtedly pulled some patients back from the death. However, this strategy of activating or boosting the body's immune system hardly benefits most patients. It is limited by low bioavailability, low response rate and severe side effects. Thankfully, the rapid development of nanotechnology has broken through the bottleneck problem of anti-tumor immunotherapy. Multifunctional nanomaterials can not only kill tumors by combining anti-tumor drugs but also can be designed to enhance the body's immunity and thus achieve a multi-treatment effect. It is worth noting that the variety of nanomaterials, their modifiability, and the diversity of combinations allow them to shine in antitumor immunotherapy. In this paper, several nanobiotics commonly used in tumor immunotherapy at this stage are discussed, and they activate or enhance the body's immunity with their unique advantages. In conclusion, we reviewed recent advances in tumor immunotherapy based on nanomaterials, such as biological cell membrane modification, self-assembly, mesoporous, metal and hydrogels, to explore new directions and strategies for tumor immunotherapy.

The role of melatonin in the development of postmenopausal osteoporosis

Melatonin is an important endogenous hormone that modulates homeostasis in the microenvironment. Recent studies have indicated that serum melatonin levels are closely associated with the occurrence and development of osteoporosis in postmenopausal women. Exogenous melatonin could also improve bone mass and increase skeletal strength. To determine the underlying mechanisms of melatonin in the prevention and treatment of postmenopausal osteoporosis, we performed this review to analyze the role of melatonin in bone metabolism according to its physiological functions. Serum melatonin is related to bone mass, the measurement of which is a potential method for the diagnosis of osteoporosis. Melatonin has a direct effect on bone remodeling by promoting osteogenesis and suppressing osteoclastogenesis. Melatonin also regulates the biological rhythm of bone tissue, which benefits its osteogenic effect. Additionally, melatonin participates in the modulation of the bone microenvironment. Melatonin attenuates the damage induced by oxidative stress and inflammation on osteoblasts and prevents osteolysis from reactive oxygen species and inflammatory factors. As an alternative drug for osteoporosis, melatonin can improve the gut ecology, remodel microbiota composition, regulate substance absorption and maintain metabolic balance, all of which are beneficial to the health of bone structure. In conclusion, our review systematically demonstrates the effects of melatonin on bone metabolism. Based on the evidence in this review, melatonin will play a more important role in the diagnosis, prevention and treatment of postmenopausal osteoporosis.

Melatonin inhibits ESCC tumor growth by mitigating the HDAC7/β-catenin/c-Myc positive feedback loop and suppressing the USP10-maintained HDAC7 protein stability

BACKGROUND

Melatonin, a natural hormone secreted by the pineal gland, has been reported to exhibit antitumor properties through diverse mechanisms of action. However, the oncostatic function of melatonin on esophageal squamous cell carcinoma (ESCC) remains elusive. This study was conducted to investigate the potential effect and underlying molecular mechanism of melatonin as single anticancer agent against ESCC cells.

METHODS

ESCC cell lines treated with or without melatonin were used in this study. In vitro colony formation and EdU incorporation assays, and nude mice tumor xenograft model were used to confirm the proliferative capacities of ESCC cells. RNA-seq, qPCR, Western blotting, recombinant lentivirus-mediated target gene overexpression or knockdown, plasmids transfection and co-IP were applied to investigate the underlying molecular mechanism by which melatonin inhibited ESCC cell growth. IHC staining on ESCC tissue microarray and further survival analyses were performed to explore the relationship between target genes' expression and prognosis of ESCC.

RESULTS

Melatonin treatment dose-dependently inhibited the proliferative ability and the expression of histone deacetylase 7 (HDAC7), c-Myc and ubiquitin-specific peptidase 10 (USP10) in ESCC cells (P < 0.05). The expressions of HDAC7, c-Myc and USP10 in tumors were detected significantly higher than the paired normal tissues from 148 ESCC patients (P < 0.001). Then, the Kaplan-Meier survival analyses suggested that ESCC patients with high HDAC7, c-Myc or USP10 levels predicted worse overall survival (Log-rank P < 0.001). Co-IP and Western blotting analyses further revealed that HDAC7 physically deacetylated and activated β-catenin thus promoting downstream target c-Myc gene transcription. Notably, our mechanistic study validated that HDAC7/β-catenin/c-Myc could form the positive feedback loop to enhance ESCC cell growth, and USP10 could deubiquitinate and stabilize HDAC7 protein in the ESCC cells. Additionally, we verified that inhibition of the HDAC7/β-catenin/c-Myc axis and USP10/HDAC7 pathway mediated the anti-proliferative action of melatonin on ESCC cells.

CONCLUSIONS

Our findings elucidate that melatonin mitigates the HDAC7/β-catenin/c-Myc positive feedback loop and inhibits the USP10-maintained HDAC7 protein stability thus suppressing ESCC cell growth, and provides the reference for identifying biomarkers and therapeutic targets for ESCC.

An Overview of Hepatocellular Carcinoma After Insufficient Radiofrequency Ablation

Radiofrequency ablation (RFA) is a commonly used treatment for hepatocellular carcinoma (HCC), however, various complex conditions in clinical practice may lead to insufficient radiofrequency ablation (IRFA), allowing residual HCC to survive. In clinical practice and laboratory models, IRFA plays an important role in rapid tumor progression. Therefore, targeting the residual HCC and avoiding IRFA were worthwhile methods. A deeper understanding of IRFA is required; IRFA contributes to the improvement of proliferative activity, migration rates, and invasive capacity, and this may be due to the involvement of multiple complex processes or proteins, including epithelial mesenchymal transitions (EMTs), cancer stem cells (CSCs), autophagy, heat shock proteins (HSPs), changes of non-tumor cells and extracellular matrix, altered immune microenvironment, hypoxia-inducible factors (HIFs), growth factors, epigenetic alterations, and metabolic reprogramming. We focus on the processes of the above mechanisms and possible therapeutic approach, with a review of the literature. Additionally, we recapitulated the construction methods of various experimental models of IRFA (in vivo and in vitro).

Use of Melatonin in Cancer Treatment: Where Are We?

Cancer represents a large group of diseases accounting for nearly 10 million deaths each year. Various treatment strategies, including surgical resection combined with chemotherapy, radiotherapy, and immunotherapy, have been applied for cancer treatment. However, the outcomes remain largely unsatisfying. Melatonin, as an endogenous hormone, is associated with the circadian rhythm moderation. Many physiological functions of melatonin besides sleep–wake cycle control have been identified, such as antioxidant, immunomodulation, and anti-inflammation. In recent years, an increasing number of studies have described the anticancer effects of melatonin. This has drawn our attention to the potential usage of melatonin for cancer treatment in the clinical setting, although huge obstacles still exist before its wide clinical administration is accepted. The exact mechanisms behind its anticancer effects remain unclear, and the specific characters impede its in vivo investigation. In this review, we will summarize the latest advances in melatonin studies, including its chemical properties, the possible mechanisms for its anticancer effects, and the ongoing clinical trials. Importantly, challenges for the clinical application of melatonin will be discussed, accompanied with our perspectives on its future development. Finally, obstacles and perspectives of using melatonin for cancer treatment will be proposed. The present article will provide a comprehensive foundation for applying melatonin as a preventive and therapeutic agent for cancer treatment.

Melatonin: highlighting its use as a potential treatment for SARS-CoV-2 infection

Numerous pharmaceutical drugs have been repurposed for use as treatments for COVID-19 disease. These drugs have not consistently demonstrated high efficacy in preventing or treating this serious condition and all have side effects to differing degrees. We encourage the continued consideration of the use of the antioxidant and anti-inflammatory agent, melatonin, as a countermeasure to a SARS-CoV-2 infection. More than 140 scientific publications have identified melatonin as a likely useful agent to treat this disease. Moreover, the publications cited provide the rationale for the use of melatonin as a prophylactic agent against this condition. Melatonin has pan-antiviral effects and it diminishes the severity of viral infections and reduces the death of animals infected with numerous different viruses, including three different coronaviruses. Network analyses, which compared drugs used to treat SARS-CoV-2 in humans, also predicted that melatonin would be the most effective agent for preventing/treating COVID-19. Finally, when seriously infected COVID-19 patients were treated with melatonin, either alone or in combination with other medications, these treatments reduced the severity of infection, lowered the death rate, and shortened the duration of hospitalization. Melatonin’s ability to arrest SARS-CoV-2 infections may reduce health care exhaustion by limiting the need for hospitalization. Importantly, melatonin has a high safety profile over a wide range of doses and lacks significant toxicity. Some molecular processes by which melatonin resists a SARS-CoV-2 infection are summarized. The authors believe that all available, potentially beneficial drugs, including melatonin, that lack toxicity should be used in pandemics such as that caused by SARS-CoV-2.

AMPK-Mediated Metabolic Switching Is High Effective for Phytochemical Levo-Tetrahydropalmatine (l-THP) to Reduce Hepatocellular Carcinoma Tumor Growth

Targeting cancer cell metabolism has been an attractive approach for cancer treatment. However, the role of metabolic alternation in cancer is still unknown whether it functions as a tumor promoter or suppressor. Applying the cancer gene-metabolism integrative network model, we predict adenosine monophosphate-activated protein kinase (AMPK) to function as a central hub of metabolic landscape switching in specific liver cancer subtypes. For the first time, we demonstrate that the phytochemical levo-tetrahydropalmatine (l-THP), a Corydalis yanhusuo-derived clinical drug, as an AMPK activator via autophagy-mediated metabolic switching could kill the hepatocellular carcinoma HepG2 cells. Mechanistically, l-THP promotes the autophagic response by activating the AMPK-mTOR-ULK1 and the ROS-JNK-ATG cascades and impairing the ERK/AKT signaling. All these processes ultimately synergize to induce the decreased mitochondrial oxidative phosphorylation (OXPHOS) and mitochondrial damage. Notably, silencing AMPK significantly inhibits the autophagic flux and recovers the decreased OXPHOS metabolism, which results in HepG2 resistance to l-THP treatment. More importantly, l-THP potently reduces the growth of xenograft HepG2 tumor in nude mice without affecting other organs. From this perspective, our findings support the conclusion that metabolic change is an alternative approach to influence the development of HCC.