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Radiotherapy and chemotherapy are two famous modalities in tumor‐targeted therapy that lead to systemic and local toxicities for normal tissues. Moreover, several studies have confirmed that exposure of the tumor to radiation or chemotherapy drugs stimulate some signaling pathways in the tumor microenvironment (TME), leading to resistance of cancer cells to apoptosis, as well as promoting angiogenesis and tumor growth. Nuclear factor kappa B (NF‐κB) plays a central role in the regulation of inflammatory responses in both normal tissues and tumors via the release of several cytokines, regulation of prostaglandins, reduction/oxidation (redox) reactions, angiogenesis, and cell death. Upregulation of NF‐κB in normal tissues causes an appearance of inflammatory reactions and oxidative stress, whereas it regulates angiogenesis and suppresses apoptosis, leading to resistance to subsequent doses of radiation or chemotherapy. Selective inhibition of NF‐κB in experimental studies has shown promising results for tumor sensitization via apoptosis induction, inhibition of angiogenesis, and increasing delay of tumor growth. The use of some agents for NF‐κB inhibition has been shown to alleviate radiation/chemotherapy toxicities in normal cells/ tissues. In this current review, we explained the pivotal role of NF‐κB in both normal tissue toxicity and tumor resistance. We also discussed the promising strategies for overcoming these problems with regard to chemotherapy and radiotherapy. [ABSTRACT FROM AUTHOR]

Background: Prostate cancer is the second most common malignancy in men in the world, and radiotherapy is used as a standard treatment modality for this cancer. Although this treatment modality effectively kills prostate cancerous cells, it unavoidably irradiates the organs/tissues that are away from the treatment site. In this regard, radiation‐induced testicular toxicities following prostate radiotherapy can affect sexual function, reproduction, and quality of life in cancer survivors. This review summarizes the available data on testicular exposure to radiation during prostate radiotherapy and the consequences on testicular function. Methods: To illuminate the radiation‐induced testicular toxicities following prostate radiotherapy, a systematic search was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guideline in PubMed, Web of Science, Scopus, Embase, and clinical trials electronic databases up to September 2018. According to a set of prespecified inclusion and exclusion criteria, 31 eligible articles providing data on testicular function following radiotherapy in patients with prostate cancer were included in the study. Results: According to the different radiotherapeutic techniques used for prostate cancer treatment, the total tumor dose and scattered testicular dose values were ranging from 36.25 to 78.00 Gy and 0.06 to 6.48 Gy, respectively. Luteinizing hormone and follicle‐stimulating hormone levels after prostate radiotherapy were significantly higher in comparison with the pretreatment levels. Around 60% of the studies showed that testosterone levels after prostate radiotherapy were significantly lower than the pretreatment levels. Furthermore, erectile dysfunction (ED), as an adverse side effect resulting from prostate radiotherapy, was reported and this complication is significantly correlated with lower satisfaction with sexual life. Testicular atrophy following prostate radiotherapy has also been observed and its frequency in patients with prior prostate radiotherapy is 2.5 times more than that in the patients without prior radiotherapy. Conclusion: The data revealed that the scattered dose to testicular tissues during prostate radiotherapy can lead to testicular atrophy, variation of the male sex hormones, and quality of sexual life. [ABSTRACT FROM AUTHOR]

Cancer incidences are growing and cause millions of deaths worldwide. Cancer therapy is one of the most important challenges in medicine. Improving therapeutic outcomes from cancer therapy is necessary for increasing patients' survival and quality of life. Adjuvant therapy using various types of antibodies or immunomodulatory agents has suggested modulating tumor response. Resistance to apoptosis is the main reason for radioresistance and chemoresistance of most of the cancers, and also one of the pivotal targets for improving cancer therapy is the modulation of apoptosis signaling pathways. Apoptosis can be induced by intrinsic or extrinsic pathways via stimulation of several targets, such as membrane receptors of tumor necrosis factor‐α and transforming growth factor‐β, and also mitochondria. Curcumin is a naturally derived agent that induces apoptosis in a variety of different tumor cell lines. Curcumin also activates redox reactions within cells inducing reactive oxygen species (ROS) production that leads to the upregulation of apoptosis receptors on the tumor cell membrane. Curcumin can also upregulate the expression and activity of p53 that inhibits tumor cell proliferation and increases apoptosis. Furthermore, curcumin has a potent inhibitory effect on the activity of NF‐κB and COX‐2, which are involved in the overexpression of antiapoptosis genes such as Bcl‐2. It can also attenuate the regulation of antiapoptosis PI3K signaling and increase the expression of MAPKs to induce endogenous production of ROS. In this paper, we aimed to review the molecular mechanisms of curcumin‐induced apoptosis in cancer cells. This action of curcumin could be applicable for use as an adjuvant in combination with other modalities of cancer therapy including radiotherapy and chemotherapy. [ABSTRACT FROM AUTHOR]

Cancer is the second cause of death worldwide. Chemotherapy and radiotherapy are the most common modalities for the treatment of cancer. Experimental studies have shown that inflammation plays a central role in tumor resistance and the incidence of several side effects following both chemotherapy and radiotherapy. Inflammation resulting from radiotherapy and chemotherapy is responsible for adverse events such as dermatitis, mucositis, pneumonitis, fibrosis, and bone marrow toxicity. Chronic inflammation may also lead to the development of second cancer during years after treatment. A number of anti‐inflammatory drugs such as nonsteroidal anti‐inflammatory agents have been proposed to alleviate chronic inflammatory reactions after radiotherapy or chemotherapy. Curcumin is a well‐documented herbal anti‐inflammatory agents. Studies have proposed that curcumin can help management of inflammation during and after radiotherapy and chemotherapy. Curcumin targets various inflammatory mediators such as cyclooxygenase‐2, inducible nitric oxide synthase, and nuclear factor κB (NF‐κB), thereby attenuating the release of proinflammatory and profibrotic cytokines, and suppressing chronic production of free radicals, which culminates in the amelioration of tissue toxicity. Through modulation of NF‐κB and its downstream signaling cascade, curcumin can also reduce angiogenesis, tumor growth, and metastasis. Low toxicity of curcumin is linked to its cytoprotective effects in normal tissues. This protective action along with the capacity of this phytochemical to sensitize tumor cells to radiotherapy and chemotherapy makes it a potential candidate for use as an adjuvant in cancer therapy. There is also evidence from clinical trials suggesting the potential utility of curcumin for acute inflammatory reactions during radiotherapy such as dermatitis and mucositis. [ABSTRACT FROM AUTHOR]

Despite great scientific breakthroughs toward understanding the identity of human hepatocellular carcinoma (HCC) mechanistically, there are still no clinically efficient therapeutic methods for this cancer. Melatonin (N‐acetyl‐5‐methoxytryptamine) is a multi‐tasking hormone that has long been known for its anti‐cancer activity against various human cancers including HCC, which is a focus of this review. PubMed database was searched for relevant articles with the keywords: hepatocellular carcinoma (HCC), melatonin, apoptosis, proliferation, invasion, angiogenesis, autophagy, oxidative stress, tumor immunity, and mitogen‐activated protein kinase (MAPK) focusing on just human cell lines and English language articles. Melatonin inhibits apoptosis resistance and activates both extrinsic and intrinsic pathways of apoptosis in HCC. Melatonin induces ensoplasmic reticulum (ER)‐ and autophagy‐mediated apoptosis in cancer cells. Melatonin works against cancer cell proliferation, motility, and invasiveness by modulating actions of a variety of transcription factors and related pathways. Melatonin also relieves an immunosuppressive state in HCC cancer cells through making a control over tumor‐derived exosomes. Both pro‐and anti‐oxidative functions of melatonin are necessary for combating HCC. Combination of melatonin with chemotherapy could also provide cumulative effects on cancer cells. Melatonin exerts most of these roles by acting on the members of MAPK family. [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) and spinal cord injury (SCI) are pathological events that lead to neuropathological conditions which have in consequence the initiation of pro‐inflammatory cytokine production. Neuroinflammation plays a key role in the secondary phase of both TBI and SCI after initial cell death. Activation of cytoplasmic inflammasome complexes is regarded as the essential step of neuroinflammation and a key trigger for neuronal death called pyroptosis. Inflammasome complexes are involved in activation of caspase‐1 which catalyzes the cleavage of pro‐interleukins into their active forms (including interleukin‐18 [IL‐18] and IL‐1β). The focus of this article is to discuss the time‐course and regulation of inflammasome assembly and activation during TBI and SCI and their targeting in designing therapeutic approaches. We particularly focus on the inflammasomes NLRP1 and NLRP3 which play a pivotal function during TBI and SCI in the central nervous system (CNS). [ABSTRACT FROM AUTHOR]

It is believed that oxidative stress is a key causing factor of liver damage induced by a variety of agents, and it is a major contributing factor in almost all conditions compromising liver function, including ischemia–reperfusion injury (IRI), nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH), liver fibrosis, liver cirrhosis, and hepatocellular carcinoma (HCC). Liver is the organ that high concentration of melatonin (N‐acetyl‐5‐methoxytryptamine) accumulates, and it is the sole organ where circulating melatonin is metabolized. Melatonin is one of the best antioxidants that protects liver, and its metabolites also have antioxidative function. Melatonin exerts its antioxidative function directly through its radical scavenging ability and indirectly through stimulation of antioxidant enzymes. The antioxidative response from melatonin in liver affects from various factors, including its dosage, route, time and duration of administration, the type of oxidative‐induced agent and species aging. This indoleamine is also an effective and promising antioxidative choice for targeting liver IRI, NAFLD, NASH, fibrosis, cirrhosis, and HCC. [ABSTRACT FROM AUTHOR]

CD8+ cytotoxic T lymphocytes (CTLs) are preferred immune cells for targeting cancer. During cancer progression, CTLs encounter dysfunction and exhaustion due to immunerelated tolerance and immunosuppression within the tumor microenvironment (TME), with all favor adaptive immune‐resistance. Cancer‐associated fibroblasts (CAFs), macrophage type 2 (M2) cells, and regulatory T cells (Tregs) could make immunologic barriers against CD8 + T cell‐mediated antitumor immune responses. Thus, CD8 + T cells are needed to be primed and activated toward effector CTLs in a process called tumor immunity cycle for making durable and efficient antitumor immune responses. The CD8 + T cell priming is directed essentially as a corroboration work between cells of innate immunity including dendritic cells (DCs) and natural killer (NK) cells with CD4 + T cells in adoptive immunity. Upon activation, effector CTLs infiltrate to the core or invading site of the tumor (so‐called infiltrated–inflamed [I–I] TME) and take essential roles for killing cancer cells. Exogenous reactivation and/or priming of CD8 + T cells can be possible using rational immunotherapy strategies. The increase of the ratio for costimulatory to coinhibitory mediators using immune checkpoint blockade (ICB) approach. Programmed death‐1 receptor (PD‐1)–ligand (PD‐L1) and CTL‐associated antigen 4 (CTLA‐4) are checkpoint receptors that can be targeted for relieving exhaustion of CD8 + T cells and renewing their priming, respectively, and thereby eliminating antigen‐expressing cancer cells. Due to a diverse relation between CTLs with Tregs, the Treg activity could be dampened for increasing the number and rescuing the functional potential of CTLs to induce immunosensitivity of cancer cells. Tumors have specific mechanisms to break T cell responses. CD8+ T cells are the key immune cells for killing cancer cells presenting major histocompatibility complex (MHC) class I molecules. For pursuing this purpose, the cells must first be primed by their cardinal interactions with dendritic cells (DCs), natural killer (NK) cells, and CD4 + T cells, among them play essential roles for this priming. Then, the primed cells are activated to form effector cytotoxic T lymphocytes (CTLs) for killing cancer cells via release of granules or induction of FasL‐mediated apoptosis. In the established tumors, however, the function of these key effector cells is suppressed by immunosuppressive cross‐talking between cancer cells with tumor stromal cells like cancer‐associated fibroblasts (CAFs), regulatory T cells (Tregs), and macrophage type 2 (M2) cells. CTL‐based therapy can distract cancer cells, and the density of CD8 + T cells infiltrated to the invasive site of tumor is a predictive marker for influencing the outcomes of immune checkpoint blockade (ICB) blockade therapy. It is suggested to use a combination of immunotherapeutic approaches for rescuing the exhausted CTLs and switching them toward their active effector profile for retaining immunoactivation within the tumor microenvironment (TME) for combatting tumors and enhancing the efficacy of chemo or radiotherapeutic approaches. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) are self‐renewable cell types that are identified in most types of liquid and solid cancers and contributed to tumor onset, expansion, resistance, recurrence, and metastasis after therapy. CSCs are identified from the expression of cell surface markers, which is tumor‐type dependent. The transition between CSCs with cancer cells and other non‐CSCs occurs in cancers, which is possibly under the control of signals from CSCs and tumor microenvironment (TME), including CSC niche. Cancer‐associated fibroblasts are among the most influential cells for promoting both differentiation of CSCs and dedifferentiation of non‐CSCs toward attaining a CSC‐like phenotype. WNT/β‐catenin, transforming growth factor‐β, Hedgehog, and Notch are important signals for maintaining self‐renewal in CSCs. An effective therapeutic strategy relies on targeting both CSCs and non‐CSCs to remove a possible chance of tumor relapse. There are multiple ways to target CSCs, including immunotherapy, hormone therapy, (mi)siRNA delivery, and gene knockout. Such approaches can be designed for suppressing CSC stemness, tumorigenic cues from TME, CSC extrinsic and/or intrinsic signaling, hypoxia or for promoting differentiation in the cells. Because of sharing a range of characteristics to normal stem/progenitor cells, CSCs must be targeted based on their unique markers and their preferential expression of antigens. Most of the tumors are occupied with a number of self‐renewing cells called cancer stem cells (CSCs) that are contributed to the initiation, maintenance, and thriving cancer. The cells have rather similar characteristics to other stem cells located in the niche of body organs, but they have not essentially the same responses to the diverse stimuli. There is evidence for repopulation of CSCs after treatment with chemo/radiotherapy, which is possibly because of their highly plastic feature. Normal stem cells have the proclivity to transform into CSCs when they undergo continuous mutagenesis or receive tumorigenic signals of the tumor microenvironment (TME). Upon this transition, CSCs receive markers from their progeny. The rate of expression of these markers in CSCs is dependent on the type of tumor. CSCs can differentiate into cancer cells. In turn, cancer cells can dedifferentiate toward attaining a CSC‐like phenotype. Cancer‐associated fibroblasts provide a supportive niche for CSCs and release external cues for regulating cancer cell stemness. An effective therapeutic strategy is to target both CSCs and non‐CSCs to preclude a possible chance of tumor recurrence. Making a control over tumorigenic clues from TME or controlling intrinsic CSC signaling are optimistic approaches to break down CSC‐related tumorigenesis. Shifting CSCs from self‐renewal to differentiation can also be therapeutic through limiting their proliferative capacity, tumor recurrence, metastasis, and resistance. [ABSTRACT FROM AUTHOR]

Regulatory T cells (Tregs) represent a low number of T‐cell population under normal conditions, and they play key roles for maintaining immune system in homeostasis. The number of these cells is extensively increased in nearly all cancers, which is for dampening responses from immune system against cancer cells, metastasis, tumor recurrence, and treatment resistance. The interesting point is that apoptotic Tregs are stronger than their live counterparts for suppressing responses from immune system. Tregs within the tumor microenvironment have extensive positive cross‐talks with other immunosuppressive cells including cancer‐associated fibroblasts, cancer cells, macrophage type 2 cells, and myeloid‐derived suppressor cells, and they have negative interactions with immunostimulatory cells including cytotoxic T lymphocytes (CTL) and natural killer cells. A wide variety of markers are expressed in Tregs, among them forkhead box P3 (FOXP3) is the most specific marker and the master regulator of these cells. Multiple signals are activated by Tregs including transforming growth factor‐β, signal transducer and activator of transcription, and mTORC1. Treg reprogramming from an immunosuppressive to immunostimulatory proinflammatory phenotype is critical for increasing the efficacy of immunotherapy. This would be applicable through selective suppression of tumor‐bearing receptors in Tregs, including FOXP3, programmed death‐1, T‐cell immunoglobulin mucin‐3, and CTL‐associated antigen‐4, among others. Intratumoral Tregs can also be targeted by increasing the ratio for CTL/Treg. Regulatory T cells (Tregs) are essential mediators of immunosuppression in established tumors. Tregs express a wide range of receptors and markers for this purpose, and they have extensive cross‐talks with almost all immunosuppressive cells of tumor stroma, including cancer‐associated fibroblasts (CAFs), macrophage type 2 (M2) cells, cancer cells, and myeloid‐derived suppressor cells (MDSCs). Treg cell‐mediated immunosuppression is more vigorous when the cells are committed to apoptosis after high exposure of the cells to the reactive oxygen species (ROS) within the tumor microenvironment (TME). Tregs can be transformed to their immunostimulatory phenotype by targeting their relative markers. This transformation is considered as a promising approach for immunotherapy of cancer. For having optimistic outcomes in targeting cancer, immunotherapy is needed to be used in combination with appropriate chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Cancer remains among the most challenging human diseases. Several lines of evidence suggest that carcinogenesis is a complex process that is initiated by DNA damage. Exposure to clastogenic agents such as heavy metals, ionizing radiation (IR), and chemotherapy drugs may cause chronic mutations in the genomic material, leading to a phenomenon named genomic instability. Evidence suggests that genomic instability is responsible for cancer incidence after exposure to carcinogenic agents, and increases the risk of secondary cancers following treatment with radiotherapy or chemotherapy. Melatonin as the main product of the pineal gland is a promising hormone for preventing cancer and improving cancer treatment. Melatonin can directly neutralize toxic free radicals more efficiently compared with other classical antioxidants. In addition, melatonin is able to regulate the reduction/oxidation (redox) system in stress conditions. Through regulation of mitochondrial nction and inhibition of pro‐oxidant enzymes, melatonin suppresses chronic oxidative stress. Moreover, melatonin potently stimulates DNA damage responses that increase the tolerance of normal tissues to toxic effect of IR and may reduce the risk of genomic instability in patients who undergo radiotherapy. Through these mechanisms, melatonin attenuates several side effects of radiotherapy and chemotherapy. Interestingly, melatonin has shown some synergistic properties with IR and chemotherapy, which is distinct from classical antioxidants that are mainly used for the alleviation of adverse events of radiotherapy and chemotherapy. In this review, we describe the anticarcinogenic effects of melatonin and also its possible application in clinical oncology. In this review, we describe the anticarcinogenic effects of melatonin and also its possible application in clinical oncology. [ABSTRACT FROM AUTHOR]

Transforming growth factor (TGF)‐β is a multitasking cytokine such that its aberrant expression is related to cancer progression and metastasis. TGF‐β is produced by a variety of cells within the tumor microenvironment (TME), and it is responsible for regulation of the activity of cells within this milieu. TGF‐β is a main inducer of epithelial–mesenchymal transition (EMT), immune evasion, and metastasis during cancer progression. TGF‐β exerts most of its functions by acting on TβRI and TβRII receptors in canonical (Smad‐dependent) or noncanonical (Smad‐independent) pathways. Members of mitogen‐activated protein kinase, phosphatidylinositol 3‐kinase/protein kinase B, and nuclear factor κβ are involved in the non‐Smad TGF‐β pathway. TGF‐β acts by complex signaling, and deletion in one of the effectors in this pathway may influence the outcome in a diverse way by taking even an antitumor role. The stage and the type of tumor (contextual cues from cancer cells and/or the TME) and the concentration of TGF‐β are other important factors determining the fate of cancer (progression or repression). There are a number of ways for targeting TGF‐β signaling in cancer, among them the special focus is on TβRII suppression. [ABSTRACT FROM AUTHOR]

Cancer therapy using oncolytic viruses is an emerging area, in which viruses are engineered to selectively propagate in tumor tissues without affecting healthy cells. Because of the advantages that adenoviruses (Ads) have over other viruses, they are more considered. To achieve tumor selectivity, two main modifications on Ads genome have been applied: small deletions and insertion of tissue‐ or tumor‐specific promoters. Despite oncolytic adenoviruses ability in tumor cell lysis and immune responses stimulation, to further increase their antitumor effects, genomic modifications have been carried out including insertion of checkpoint inhibitors and antigenic or immunostimulatory molecules into the adenovirus genome and combination with dendritic cells and chemotherapeutic agents. This study reviews oncolytic adenoviruses structures, their antitumor efficacy in combination with other therapeutic strategies, and finally challenges around this treatment approach. 1.Cancer therapy using oncolytic viruses is an emerging area, in which viruses are engineered to selectively propagate in tumor tissues without affecting healthy cells.2.Despite oncolytic adenoviruses ability in tumor cell lysis and immune responses stimulation, some combinations have been applied to increase their antitumor effects. [ABSTRACT FROM AUTHOR]

Tumor microenvironment (TME) is a host for a complex network of heterogeneous stromal cells with overlapping or opposing functions depending on the dominant signals within this milieu. Reciprocal paracrine interactions between cancer cells with cells within the tumor stroma often reshape the TME in favor of the promotion of tumor. These complex interactions require more sophisticated approaches for cancer therapy, and, therefore, advancing knowledge about dominant drivers of cancer within the TME is critical for designing therapeutic schemes. This review will provide knowledge about TME architecture, multiple signaling, and cross communications between cells within this milieu, and its targeting for immunotherapy of cancer. Cross‐talks between various cells in the stroma of tumor microenvironment (TME) in favor of or against of tumor progression. Release of a variety of proteins, transcription factors, cytokines, chemokines, and so forth from cells inside the TME direct the fate of cancer. Concentration of these TME components along with temperature, circadian rhythm, and pH inside this microenvironment determine the fate of signaling. Complexity of the TME is a reason for failure of most of the conventional therapies against cancer. [ABSTRACT FROM AUTHOR]

Cyclooxygenase‐2 (COX‐2) is frequently expressed in many types of cancers exerting a pleiotropic and multifaceted role in genesis or promotion of carcinogenesis and cancer cell resistance to chemo‐ and radiotherapy. COX‐2 is released by cancer‐associated fibroblasts (CAFs), macrophage type 2 (M2) cells, and cancer cells to the tumor microenvironment (TME). COX‐2 induces cancer stem cell (CSC)‐like activity, and promotes apoptotic resistance, proliferation, angiogenesis, inflammation, invasion, and metastasis of cancer cells. COX‐2 mediated hypoxia within the TME along with its positive interactions with YAP1 and antiapoptotic mediators are all in favor of cancer cell resistance to chemotherapeutic drugs. COX‐2 exerts most of the functions through its metabolite prostaglandin E2. In some and limited situations, COX‐2 may act as an antitumor enzyme. Multiple signals are contributed to the functions of COX‐2 on cancer cells or its regulation. Members of mitogen‐activated protein kinase (MAPK) family, epidermal growth factor receptor (EGFR), and nuclear factor‐κβ are main upstream modulators for COX‐2 in cancer cells. COX‐2 also has interactions with a number of hormones within the body. Inhibition of COX‐2 provides a high possibility to exert therapeutic outcomes in cancer. Administration of COX‐2 inhibitors in a preoperative setting could reduce the risk of metastasis in cancer patients. COX‐2 inhibition also sensitizes cancer cells to treatments like radio‐ and chemotherapy. Chemotherapeutic agents adversely induce COX‐2 activity. Therefore, choosing an appropriate chemotherapy drugs along with adjustment of the type and does for COX‐2 inhibitors based on the type of cancer would be an effective adjuvant strategy for targeting cancer. Cyclooxygenase‐2 (COX‐2) is frequently expressed in many types of cancers exerting a pleiotropic and multifaceted role in genesis or promotion of carcinogenesis and cancer cell resistance to chemo‐ and radiotherapy. COX‐2 is released by cancer‐associated fibroblasts (CAFs), macrophage type 2 (M2) cells, and cancer cells to the tumor microenvironment (TME). COX‐2 induces cancer stem cell (CSC)‐like activity and promotes apoptotic resistance, proliferation, angiogenesis, inflammation, invasion, and metastasis of cancer cells. [ABSTRACT FROM AUTHOR]

Melatonin is a multifunctional hormone that has long been known for its antitumoral effects. An advantage of the application of melatonin in cancer therapy is its ability to differentially influence tumors from normal cells. In this review, the roles of melatonin adjuvant therapy in human cancer are discussed. Combination of melatonin with chemotherapy could provide synergistic antitumoral outcomes and resolve drug resistance in affected patients. This combination reduces the dosage for chemotherapeutic agents with the subsequent attenuation of side effects related to these drugs on normal cells around tumor and on healthy organs. The combination therapy increases the rate of survival and improves the quality of life in affected patients. Cancer cell viability is reduced after application of the combinational melatonin therapy. Melatonin does all these functions by adjusting the signals involved in cancer progression, re‐establishing the dark/light circadian rhythm, and disrupting the redox system for cancer cells. To achieve effective therapeutic outcomes, melatonin concentration along with the time of incubation for this indoleamine needs to be adjusted. Importantly, a special focus is required to be made on choosing an appropriate chemotherapy agent for using in combination with melatonin. Because of different sensitivities of cancer cells for melatonin combination therapy, cancer‐specific targeted therapy is also needed to be considered. For this review, the PubMed database was searched for relevant articles based on the quality of journals, the novelty of articles published by the journals, and the number of citations per year focusing only on human cancers. Combination of melatonin with chemotherapy for targeting human cancer. Combination of melatonin with chemotherapy could provide synergistic antitumoral outcomes and resolve drug resistance in affected patients. This combination reduces the dosage for chemotherapeutic agents with the subsequent attenuation of side effects related to these drugs on normal cells around tumor and on healthy organs. The combination therapy increases the rate of survival and improves the quality of life in affected patients. Cancer cell viability is reduced after application of the combinational melatonin therapy. [ABSTRACT FROM AUTHOR]

Colorectal cancer (CRC) is the third most prevalent cancer in the world. There are many risk factors involved in CRC. According to recent findings, the tumor microenvironment and feces samples of patients with CRC are enriched by Fusobacterium nucleatum. Thus, F. nucleatum is proposed as one of the risk factors in the initiation and progression of CRC. The most important mechanisms of Fusobacterium nucleatum involved in CRC carcinogenesis are immune modulation (such as increasing myeloid‐derived suppressor cells and inhibitory receptors of natural killer cells), virulence factors (such as FadA and Fap2), microRNAs (such as miR‐21), and bacteria metabolism. The aim of this review was to evaluate the mechanisms underlying the action of F. nucleatum in CRC. One of the probabilities in colorectal cancer (CRC) development is Fusobacterium. F. nucleatum could contribute in CRC development through virulence factors, microRNAs (miRNA), immune evasion, and increasing metastasis. [ABSTRACT FROM AUTHOR]