The effect of SP/NK1R on expression and activity of glutaredoxin and thioredoxin proteins in prostate cancer cells.

Substance P (SP), an important neuropeptide, has a crucial role in the progression of several cancers, including prostate cancer, through interacting with the neurokinin-1 receptor (NK1R). Oxidative stress is also involved in the onset and progression of prostate cancer. However, no studies have been performed on the cross-talk between the SP/NK1R system and cellular redox balance in prostate cancer, and how it is involved in tumorogenesis. We aimed to investigate the effect of the SP/NK1R system and the blockage of NK1R with its specific antagonist (aprepitant) on the cellular redox status of the prostate cancer cell line (PC3 and LNCaP). We performed the resazurin assay to evaluate the toxicity of the aprepitant on the PC3 and LNCaP cell lines. The intracellular reactive oxygen species (ROS) level was measured after SP and aprepitant treatment. The alterations of expression and activity of two crucial cellular oxidoreductases, glutaredoxin, and thioredoxin were evaluated by qRT-PCR and commercial kits (ZellBio GmbH), respectively. Our results revealed that SP increased ROS production and decreased the expression and activity of glutaredoxin and thioredoxin. On the other hand, treatment of cells with aprepitant showed reverse results. In conclusion, we found that the SP/NK1R system could promote prostate cancer progression by inducing oxidative stress. In addition, the inhibition of NK1R by aprepitant modulated the effect of the SP/NK1R system on the cellular redox system. Aprepitant might therefore be introduced as a candidate for the treatment of prostate cancer; however, more studies are required to confirm the validation of this hypothesis.

Effect of folic acid-linked chitosan-coated PLGA-based curcumin nanoparticles on the redox system of glioblastoma cancer cells.

OBJECTIVES: Oxidative stress is one of the carcinogenic mechanisms underlying the development of glioblastoma multiforme (GBM), a highly aggressive brain tumor type associated with poor prognosis. Curcumin is known to be an efficient antioxidant, anti-inflammatory, and anticancer compound. However, its poor solubility in water, inappropriate pharmacokinetics, and low bioavailability limit its use as an antitumor drug. We prepared PLGA-based curcumin nanoparticles changed with folic acid and chitosan (curcumin-PLGA-CS-FA) and evaluated its effects on GBM tumor cells' redox status. METHODS: The nanoprecipitation method was used to synthesize CU nanoparticles (CU-NPs). The size, morphology, and stability were characterized by DLS, SEM, and zeta potential analysis, respectively. The CU-NPs' toxic properties were studied by MTT assay and measuring the intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) concentrations. The study was completed by measuring the gene expression levels and activity of superoxide dismutase, catalase, glutaredoxin, and thioredoxin antioxidant enzymes. RESULTS: The size, polydispersity index, and zeta potential of CU-NPs were 77.27 nm, 0.29, and -22.45 mV, respectively. The encapsulation efficiency was approximately 98%. Intracellular ROS and MDA levels decreased after CU-NP treatment. Meanwhile, the CU-NPs increased gene expression and activity of superoxide dismutase, catalase, glutaredoxin, and thioredoxin antioxidant enzymes. CONCLUSION: CU-NPs might be effective in the prevention and treatment of glioblastoma cancer by modulating the antioxidant-oxidant balance.

The Effect of Blocking Neurokinin-1 Receptor by Aprepitant on the Inflammatory and Apoptosis Pathways in Human Ovarian Cancer Cells.

Ovarian cancer is the seventh most common cancer globally, and the second most common cancer among women with significant mortality. Toward this end, it is shown that substance P (SP) is involved in tumor initiation and progression through the neurokinin-1 receptor (NK1R). However, the exact molecular mechanism of the SP/NK1R system in ovarian cancer is not yet fully clarified. In this in vitro study, we decided to investigate the effect of the SP/NK1R system and blockage of NK1R by its specific antagonist (Aprepitant) on the proliferation of ovarian cancer cells as well as the alteration of inflammatory pathways. Our results revealed that Aprepitant stimulated apoptotic cell death and attenuated inflammation of ovarian cancer cells through the NF-kB and P53 signaling pathways. After treatment with Aprepitant, the expression of downstream anti-apoptotic genes related to the NF-kB pathway (survivine and bcl2) was decreased. However, we indicated the positive effect of SP on the proliferation of ovarian cancer cells by inducing the expression of NF-kB protein and NF-kB anti-apoptotic target genes. Moreover, Pro-apoptotic p53 target genes (P21 and Bax) were increased through aprepitant treatment, while SP attenuated these genes' expression. Besides, ROS generation in ovarian cancer cells after treatment with SP induced, while blocking of NK1R with Aprepitant reduced the level of ROS generation. Given this, our data suggest that this NK1R might be used as an important therapeutic target in ovarian cancer and Aprepitant could be considered a new drug in ovarian cancer therapy.

The effect of substance P and its specific antagonist (aprepitant) on the expression of MMP-2, MMP-9, VEGF, and VEGFR in ovarian cancer cells.

BACKGROUND: Substance P (SP) has a crucial role in cancer initiation and progression via binding to its specific receptor (NK1R). Various evidence confirmed the overexpression of NK1R and SP in the tissue of multiple cancers, including ovarian cancer. Despite numerous studies, the mechanism of the SP/NK1R system on migration and angiogenesis of ovarian cancer cells has not yet been deciphered. In this study, considering the critical factors in cell migration (MMP-2, MMP-9) and angiogenesis (VEGF, VEGFR), we investigated the possible mechanism of this system in inducing migration and angiogenesis of ovarian cancer cells. METHODS AND RESULTS: First, the resazurin assay was conducted to evaluate the cytotoxic effect of aprepitant (NK1R antagonist) on the viability of A2780 ovarian cancer cells. After that, the impact of this system and aprepitant on the mRNA expression of the factors mentioned above were studied using RT-PCR. Besides, the scratch assay was performed to confirm the effect of the SP/NK-1R system and aprepitant on cell migration. Our results implied that this system induced cell migration and angiogenesis by increasing the mRNA expression of MMP-2, MMP-9, VEGF, and VEGFR. The obtained results from the scratch assay also confirmed the positive effect of this system on cell migration. Meanwhile, the blocking of NK1R by aprepitant suppresses the SP effects on cell migration and angiogenesis. CONCLUSIONS: Overall, the SP/NK1R system plays a vital role in ovarian cancer progression, and the inhibition of NK1Rusing aprepitant could inhibit the spread of ovarian cancer cells through metastasis and angiogenesis.

Investigation of the Role of Neurokinin-1 Receptor Inhibition Using Aprepitant in the Apoptotic Cell Death through PI3K/Akt/NF-κB Signal Transduction Pathways in Colon Cancer Cells.

BACKGROUND: Colorectal cancer (CRC) is recognized as one of the most common malignancies with a high mortality rate worldwide, supporting the necessity for an effective novel antitumor drug to improve current therapy's effectiveness. Substance P (SP) is the essential member of the tachykinins (TKs) family, which binds to the specific receptors, known as neurokinin-1 receptor (NK1R), exerting its multiple influences such as tumor cell proliferation, angiogenesis, and metastasis. Aprepitant, as a specific NK1R antagonist, is suggested as a novel antitumor agent, promoting apoptotic processes in tumor cells; however, the exact antitumor mechanism of aprepitant on molecular signaling in CRC is not entirely known. METHOD: The resazurin assay was conducted to assess the cytotoxic effects of aprepitant on the viability of the CRC cell line (SW480). The level of reactive oxygen species (ROS) was measured after 24-hour treatment with SP and aprepitant. PI/annexin V-FITC staining was conducted to assess apoptosis. Also, the expression of NF-κB antiapoptotic target genes and proapoptotic p53 target genes was measured by real-time- (RT-) PCR assay. Western blotting assay was performed to determine the expression of PI3k/AKT/NF-κB proteins. RESULTS: We found that aprepitant stimulates apoptotic cell death and attenuates the PI3K/Akt pathway and its downstream proapoptotic target gene, including NF-κB in SW480 cells. Also, the obtained results from the quantitative RT-PCR assay showed that aprepitant could decrease the level of mRNA of NF-κB antiapoptotic target genes. CONCLUSION: Towards this end, this study suggests that SP/NK1R system plays a vital role in the development of CRC, and pharmaceutical targeting of NK1R using aprepitant might be a promising treatment against CRC.

Evaluation of serum level of substance P and tissue distribution of NK-1 receptor in colorectal cancer.

Colorectal cancer (CRC) is known as the most common form of malignancies in the world and its occurrence is annually increasing. Due to the relatively high death rates in patients, finding better diagnostic and prognostic factors are required. Substance P (SP) belongs to the tachykinin family that acts as an immunomodulator by binding to the neurokinin-1 receptor (NK1R). The interaction of SP with NK1R might be involved in tumor cell proliferation, angiogenesis, and migration. Hence, this study was aimed to evaluate the serum SP level and tissue distribution of NK1Rs in CRC. Also, we assessed the relationship between tissue distribution of NK1R and some different tumor characteristics, including tumor size, and lymph node status. Recruiting 38 patients primarily diagnosed with CRC, the tissue distribution of NK1R was immunohistochemically evaluated in tumor tissues and their adjacent normal tissue. The serum level of SP was measured using an ELISA method in both cases and healthy control group. The SP value was significantly increased in the serum of patients in comparison with the healthy group (p = 0.001). Tumor tissues expressed a higher number of NK1R than adjacent normal tissues (p = 0.01) considering both the percentage of stained cells and intensity of staining. However, there was not any statistically significant relevance between NK1R distribution and tumor characteristics. The SP/NK1R system is involved in tumorigenesis of CRC, and might be suggested as a potent prognostic or diagnostic factor, or a new target in the treatment of CRC.

Role of tumor microenvironment in the regulation of PD-L1: A novel role in resistance to cancer immunotherapy.

Tumor evasion from the host immune system is a substantial strategy for tumor development and survival. The expression of many immune checkpoint proteins in cancer cells is a mechanism by which tumor cells escape from the immune system. Among the well-known immune checkpoints that can tremendously affect tumor development and cancer therapy are the programmed death-ligand-1/programmed death-1 (PD-L1/PD-1). To tackle this phenomenon and improve the therapeutic strategies in cancer treatment, the blockade of the PD-L1/PD-1 pathway is introduced as a target, but the therapeutic advantage of PD L1/PD-1 blockade has not fulfilled the expectations. This condition may be associated with a different type of resistance in a considerable number of patients. A crucial issue to conquer resistance against immune checkpoint blockade therapy is to understand how PD-L1 level is regulated. However, the mechanisms by which the PD-L1 expression is regulated are complicated, and they can occur at different levels from signaling pathways to posttranscriptional levels. For example, various transcriptional factors, such as hypoxia-inducible factor-1, nuclear factor-κΒ, interferon-γ, STAT3, MYC, and AP-1 can regulate the PD-L1 distribution at the transcriptional level. Herein, we tried to focus on the most important regulatory mechanisms of PD-L1 by inducible agents in the tumor cells, such as signaling pathways, transcriptional factors, and posttranscriptional factors. Finally, these approaches may open up new windows for targeting tumor immune evasion and suggest the novel suppressors of PD-L1 for efficient therapeutics.

Cytokines as potential combination agents with PD-1/PD-L1 blockade for cancer treatment.

Immunotherapy has caused a paradigm shift in the treatment of several malignancies, particularly the blockade of programmed death-1 (PD-1) and its specific receptor/ligand PD-L1 that have revolutionized the treatment of a variety of malignancies, but significant durable responses only occur in a small percentage of patients, and other patients failed to respond to the treatment. Even those who initially respond can ultimately relapse despite maintenance treatment, there is considerable potential for synergistic combinations of immunotherapy and chemotherapy agents with immune checkpoint inhibitors into conventional cancer treatments. The clinical experience in the use of cytokines in the clinical setting indicated the efficiency of cytokine therapy in cancer immunotherapy. Combinational approaches to enhancing PD-L1/PD-1 pathways blockade efficacy with several cytokines such as interleukin (IL)-2, IL-15, IL-21, IL-12, IL-10, and interferon-α (IFN-α) may result in additional benefits. In this review, the current state of knowledge about PD-1/PD-L1 inhibitors, the date in the literature to ascertain the combination of anti-PD-1/PD-L1 antibodies with cytokines is discussed. Finally, it is noteworthy that novel therapeutic approaches based on the efficient combination of recombinant cytokines with the PD-L1/PD-1 blockade therapy can enhance antitumor immune responses against various malignancies.

The thioredoxin system and cancer therapy: a review.

Thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH are key members of the Trx system that is involved in redox regulation and antioxidant defense. In recent years, several researchers have provided information about the roles of the Trx system in cancer development and progression. These reports indicated that many tumor cells express high levels of Trx and TrxR, which can be responsible for drug resistance in tumorigenesis. Inhibition of the Trx system may thus contribute to cancer therapy and improving chemotherapeutic agents. There are now a number of effective natural and synthetic inhibitors with chemotherapy applications possessing antitumor activity ranging from oxidative stress induction to apoptosis. In this article, we first described the features and functions of the Trx system and then reviewed briefly its correlations with cancer. Finally, we summarized the present knowledge about the Trx/TrxR inhibitors as anticancer drugs.

Recent advances in the clinical development of immune checkpoint blockade therapy.

BACKGROUND: The discovery of immune checkpoint proteins and the mechanisms by which cancer cells utilize them to evade the immune system has transformed our approach to cancer immunotherapy. Checkpoint blockade antibodies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1) and its ligands such as programmed cell death ligand 1 (PD-L1) have already revolutionized the treatment of multiple types of cancer and have significantly improved treatment and survival outcomes of patients affected by these malignancies. CONCLUSIONS: Herein, we summarize current knowledge about the role of, and the mechanisms underlying PD-1/PD-L1 signaling pathways in antitumor immune responses, with particular emphasis on clinical studies evaluating the efficacy of anti-PD-1/PD-L1 blockade in various tumor types. Preliminary clinical investigations with immune-checkpoint blockers highlight broad opportunities with a high potential to enhance antitumor immunity and, as such, to generate significant clinical responses. These preliminary successes open up new avenues towards efficient therapeutics offered to patients.