Phenethyl isothiocyanate suppresses the metastasis of ovarian cancer associated with the inhibition of CRM1-mediated nuclear export and mTOR-STAT3 pathway

Natural STAT3 Inhibitors for Cancer Treatment: A Comprehensive Literature Review

Cancer is one of the leading causes of mortality and morbidity worldwide, affecting millions of people physically and financially every year. Over time, many anticancer treatments have been proposed and studied, including synthetic compound consumption, surgical procedures, or grueling chemotherapy. Although these treatments have improved the daily life quality of patients and increased their survival rate and life expectancy, they have also shown significant drawbacks, including staggering costs, multiple side effects, and difficulty in compliance and adherence to treatment. Therefore, natural compounds have been considered a possible key to overcoming these problems in recent years, and thorough research has been done to assess their effectiveness. In these studies, scientists have discovered a meaningful interaction between several natural materials and signal transducer and activator of transcription 3 molecules. STAT3 is a transcriptional protein that is vital for cell growth and survival. Mechanistic studies have established that activated STAT3 can increase cancer cell proliferation and invasion while reducing anticancer immunity. Thus, inhibiting STAT3 signaling by natural compounds has become one of the favorite research topics and an attractive target for developing novel cancer treatments. In the present article, we intend to comprehensively review the latest knowledge about the effects of various organic compounds on inhibiting the STAT3 signaling pathway to cure different cancer diseases.

Aberrant serum and tissue levels of Beclin1 and mechanistic target of rapamycin (mTOR) proteins in epithelial ovarian cancer

Beclin1 and mechanistic target of rapamycin (mTOR) can be used as tumor markers of epithelial ovarian cancer. This study aimed to assess the association of Beclin1 and mTOR expression with clinicopathological and prognostic data in epithelial ovarian cancer patients. Serum and tissue samples from 45 epithelial ovarian cancer patients and 20 controls were analyzed by enzyme-linked immunosorbent assay and immunohistochemistry for Beclin1 and mTOR expression. The online datasets from gene expression profiling interactive analysis (n = 426), Kaplan-Meier plotter (n = 398), cBioPortal (n = 585), and UALCAN (n = 302) were also analyzed. Beclin1 expression was associated with low-grade differentiation (P = .003), earlier clinical stage (P = .013), fewer local lymph node metastases (P = .02) and lower serum Beclin1 level (P = .001). mTOR expression was associated with high-grade differentiation (P = .013), advanced clinical stage (P = .021), ascites (P = .028), and higher serum mTOR level (P = .001). The online datasets showed that a high mTOR expression level (HR = 1.44; 95% CI = 1.08-1.92; P = .013) was associated with a poor overall survival of 426 patients. Beclin1 was mutated in 1.8% and mTOR was mutated in 5% of epithelial ovarian cancer patients. Serum Beclin1 and mTOR levels were able to predict tumor differentiation, clinical stage, lymph node metastasis, and ascites in epithelial ovarian cancer patients.

Reviewing the Prospective Pharmacological Potential of Isothiocyanates in Fight against Female-Specific Cancers

Gynecological cancers are the most commonly diagnosed malignancies in females worldwide. Despite the advancement of diagnostic tools as well as the availability of various therapeutic interventions, the incidence and mortality of female-specific cancers is still a life-threatening issue, prevailing as one of the major health problems worldwide. Lately, alternative medicines have garnered immense attention as a therapeutic intervention against various types of cancers, seemingly because of their safety profiles and enhanced effectiveness. Isothiocyanates (ITCs), specifically sulforaphane, benzyl isothiocyanate, and phenethyl isothiocyanate, have shown an intriguing potential to actively contribute to cancer cell growth inhibition, apoptosis induction, epigenetic alterations, and modulation of autophagy and cancer stem cells in female-specific cancers. Additionally, it has been shown that ITCs plausibly enhance the chemo-sensitization of many chemotherapeutic drugs. To this end, evidence has shown enhanced efficacy in combinatorial regimens with conventional chemotherapeutic drugs and/or other phytochemicals. Reckoning with these, herein, we discuss the advances in the knowledge regarding the aspects highlighting the molecular intricacies of ITCs in female-specific cancers. In addition, we have also argued regarding the potential of ITCs either as solitary treatment or in a combinatorial therapeutic regimen for the prevention and/or treatment of female-specific cancers. Hopefully, this review will open new horizons for consideration of ITCs in therapeutic interventions that would undoubtedly improve the prognosis of the female-specific cancer clientele. Considering all these, it is reasonable to state that a better understanding of these molecular intricacies will plausibly provide a facile opportunity for treating these female-specific cancers.

Eradication of Myrosinase-Tethered Cancer Cells by Allyl Isothiocyanate Derived from Enzymatic Hydrolysis of Sinigrin

Sinigrin is present in significant amounts in cruciferous vegetables. Epidemiological studies suggest that the consumption of such vegetables decreases the risk of cancer, and the effect is attributed mainly to allyl isothiocyanate (AITC), a hydrolysis product of sinigrin catalyzed by myrosinase. Anticancer activity of AITC has been previously investigated for several cancer models, but less attention was paid to delivering AITC on the target site. In this study, the gene sequences of core streptavidin (coreSA) and myrosinase (MYR) were cloned in a pET-30a(+) plasmid and transformed into BL21(DE3) E. coli competent cells. The MYR-coreSA chimeric protein was expressed and purified using immobilized metal affinity chromatography and further characterized by gel electrophoresis, Western blot, and enzyme activity assay. The purified MYR-coreSA chimeric protein was tethered on the outer membrane of biotinylated adenocarcinoma A549 cells and then treated with various concentrations of sinigrin. Our results showed that 20 µM of sinigrin inhibited the growth of A549 cells tethered with myrosinase by ~60% in 48 h. Furthermore, the levels of treated cells undertaken apoptosis were determined by Caspase-3/7 activation and Annexin-V. In summary, sinigrin harnessed like a prodrug catalyzed by myrosinase to the production of AITC, which induced cell apoptosis and arrested the growth of lung cancer cells.

Diagnostic value of beclin-1 and mTOR in ovarian cancer

This study described the expression of beclin-1 and mTOR proteins in 86 ovarian tumor tissue samples (n=25 benign ovarian tumor tissues; n=16 borderline ovarian tumor tissues; n=45 malignant epithelial ovarian tumor tissues) and 20 normal ovarian tissue samples and determined the diagnostic value of serum beclin-1 and mTOR protein levels for ovarian tumors. Serum and tissue beclin-1 and mTOR protein levels were detected with enzyme-linked immunosorbent assay, western blot, and immunohistochemistry. Receiver operating characteristic (ROC) curves were constructed to determine the significance of serum beclin-1 and mTOR protein levels for diagnosing borderline and malignant epithelial ovarian tumor. Mean beclin-1 protein levels were highest in normal ovarian tissue and were progressively decreased in benign, borderline, and malignant epithelial ovarian tumor. Mean mTOR protein levels were lowest in normal ovarian tissue and were progressively increased in benign, borderline, and malignant epithelial ovarian tumor. The area under the ROC curve was 0.93 or 0.97 when a combination of serum beclin-1 and mTOR protein levels was used to diagnose borderline or malignant epithelial ovarian tumor. There was a significant negative correlation between beclin-1 and mTOR protein expression in malignant epithelial ovarian tumor (r_s=-0.78, P<0.05), but no correlation between beclin-1 and mTOR protein expression in borderline ovarian tumor. Combined detection of serum beclin-1 and mTOR protein levels may have improved diagnostic accuracy for malignant epithelial ovarian tumor compared to each marker alone.

Phytochemicals in Gynecological Cancer Prevention

Gynecological cancer confers an enormous burden among women worldwide. Accumulating evidence points to the role of phytochemicals in preventing cervical, endometrial, and ovarian cancer. Experimental studies emphasize the chemopreventive and therapeutic potential of plant-derived substances by inhibiting the early stages of carcinogenesis or improving the efficacy of traditional chemotherapeutic agents. Moreover, a number of epidemiological studies have investigated associations between a plant-based diet and cancer risk. This literature review summarizes the current knowledge on the phytochemicals with proven antitumor activity, emphasizing their effectiveness and mechanism of action in gynecological cancer.

Dietary isothiocyanates inhibit cancer progression by modulation of epigenome

Cell cycle, growth, survival and metabolism are tightly regulated together and failure in cellular regulation leads to carcinogenesis. Several signaling pathways like the PI3K, WNT, MAPK and NFKb pathway exhibit aberrations in cancer and help achieve hallmark capabilities. Clinical research and in vitro studies have highlighted the role of epigenetic alterations in cancer onset and development. Altered gene expression patterns enabled by changes in DNA methylation, histone modifications and RNA processing have proven roles in cancer hallmark acquisition. The reversible nature of epigenetic processes offers robust therapeutic targets. Dietary bioactive compounds offer a vast compendium of effective therapeutic moieties. Isothiocyanates (ITCs) sourced from cruciferous vegetables demonstrate anti-proliferative, pro-apoptotic, anti-inflammatory, anti-migratory and anti-angiogenic effect against several cancers. ITCs also modulate the redox environment, modulate signaling pathways including PI3K, MAPK, WNT, and NFkB. They also modulate the epigenetic machinery by regulating the expression and activity of DNA methyltransferases, histone modifiers and miRNA. This further enhances their transcriptional modulation of key cellular regulators. In this review, we comprehensively assess the impact of ITCs such as sulforaphane, phenethyl isothiocyanate, benzyl isothiocyanate and allyl isothiocyanate on cancer and document their effect on various molecular targets. Overall, this will facilitate consolidation of the current understanding of the anti-cancer and epigenetic modulatory potential of these compounds and recognize the gaps in literature. Further, we discuss avenues of future research to develop these compounds as potential therapeutic entities.

Inhibition of chromosomal region maintenance 1 suppresses the migration and invasion of glioma cells via inactivation of the STAT3/MMP2 signaling pathway

Chromosomal region maintenance 1 (CRM1) is associated with an adverse prognosis in glioma. We previously reported that CRM1 inhibition suppressed glioma cell proliferation both in vitro and in vivo. In this study, we investigated the role of CRM1 in the migration and invasion of glioma cells. S109, a novel reversible selective inhibitor of CRM1, was used to treat Human glioma U87 and U251 cells. Cell migration and invasion were evaluated by wound-healing and transwell invasion assays. The results showed that S109 significantly inhibited the migration and invasion of U87 and U251 cells. However, mutation of Cys528 in CRM1 abolished the inhibitory activity of S109 in glioma cells. Furthermore, we found that S109 treatment decreased the expression level and activity of MMP2 and reduced the level of phosphorylated STAT3 but not total STAT3. Therefore, the inhibition of migration and invasion induced by S109 may be associated with the downregulation of MMP2 activity and expression, and inactivation of the STAT3 signaling pathway. These results support our previous conclusion that inhibition of CRM1 is an attractive strategy for the treatment of glioma.

Crm1 knockdown by specific small interfering RNA reduces cell proliferation and induces apoptosis in head and neck cancer cell lines

Head and neck squamous cell carcinoma (HNSCC) is the most common and most aggressive type of head and neck cancer. Current approaches for the treatment of HNSCC are not sufficient to increase the patient survival or to reduce the high recurrence rate. Consequently, there is a need to explore the molecular characteristics of this cancer in order to discover potential therapeutic target molecules. The overexpression of chromosome region maintenance 1 (Crm1), responsible for the transport of different classes of macromolecules from the nuclear membrane to the cytoplasm, in various cancer cells has made it an attractive target molecule in cancer research. It has been reported that transcription factors, which are the target cargo proteins of Crm1, have critical roles in regulating intracellular processes via their expression levels and functions, which in turn are regulated by the cell cycle and signaling proteins. Previous findings show that head and neck cancer cells overexpress Crm1 and that these cells become highly dependent on Crm1 function. The results of this study show that after decreasing Crm1 expression levels in HNSCC cells through either treatment with specific Crm1 RNA interference (siRNA) or the selective Crm1 inhibitor leptomycin B (LMB), cell viability, proliferation, migration, and wound-healing abilities decreased, suppressing tumorigenic properties through the induction of apoptosis. Crm1 is a powerful diagnostic biomarker because of its central role in cancerogenesis, and it has a high potential for the development of targeted Crm1 molecules or synthetic agents, such as LMB, as well as for the improvement of the clinical features in head and neck cancer.

Expression of exportin-1 in diffuse large B-cell lymphoma: immunohistochemistry and TCGA analyses

Exportin-1 (XPO1) is an essential nuclear export receptor that is involved in the pathogenesis of multiple tumors. However, the role of XPO1 in diffuse large B-cell lymphoma (DLBCL) requires clarification. This study aims to detect XPO1 expression in DLBCL and to explore its relationships with clinicopathologic parameters and prognoses.

METHODS

A total of 131 cases of DLBCL and 30 cases of reactive lymphoid hyperplasia were selected for immunohistochemistry to examine XPO1 expression and analyze the relationships of XPO1 expression with clinicopathologic parameters and prognosis. DLBCL datasets downloaded from The Cancer Genome Atlas (TCGA) were used to analyze the mutations, expressions, and clinical values of XPO1 in DLBCL.

RESULTS

XPO1 expression was markedly upregulated in DLBCL compared to the reactive lymphoid hyperplasia group (χ² = 10.734, P = 0.001). High XPO1 expression was associated with an advanced clinical stage (χ² = 4.036, P = 0.045) and a risky International Prognostic Index (IPI) score (χ² = 5.301, P = 0.025). Moreover, high XPO1 expression was associated with a lower overall survival rate compared with low expression (P = 0.043). XPO1 was an independent prognostic factor for DLBCL (risk ratio, RR = 3.772, P = 0.006). Furthermore, XPO1 overexpression in DLBCL was correlated with a high IPI score (P = 0.024) in TCGA datasets.

CONCLUSION

High XPO1 expression in DLBCL was related to an advanced clinical stage, poor IPI score, and poor prognosis. Thus, XPO1 may be useful for condition identification and prognostic assessment.

Anti-Carcinogenic Glucosinolates in Cruciferous Vegetables and Their Antagonistic Effects on Prevention of Cancers

Glucosinolates (GSL) are naturally occurring β-d-thioglucosides found across the cruciferous vegetables. Core structure formation and side-chain modifications lead to the synthesis of more than 200 types of GSLs in Brassicaceae. Isothiocyanates (ITCs) are chemoprotectives produced as the hydrolyzed product of GSLs by enzyme myrosinase. Benzyl isothiocyanate (BITC), phenethyl isothiocyanate (PEITC) and sulforaphane ([1-isothioyanato-4-(methyl-sulfinyl) butane], SFN) are potential ITCs with efficient therapeutic properties. Beneficial role of BITC, PEITC and SFN was widely studied against various cancers such as breast, brain, blood, bone, colon, gastric, liver, lung, oral, pancreatic, prostate and so forth. Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a key transcription factor limits the tumor progression. Induction of ARE (antioxidant responsive element) and ROS (reactive oxygen species) mediated pathway by Nrf2 controls the activity of nuclear factor-kappaB (NF-κB). NF-κB has a double edged role in the immune system. NF-κB induced during inflammatory is essential for an acute immune process. Meanwhile, hyper activation of NF-κB transcription factors was witnessed in the tumor cells. Antagonistic activity of BITC, PEITC and SFN against cancer was related with the direct/indirect interaction with Nrf2 and NF-κB protein. All three ITCs able to disrupts Nrf2-Keap1 complex and translocate Nrf2 into the nucleus. BITC have the affinity to inhibit the NF-κB than SFN due to the presence of additional benzyl structure. This review will give the overview on chemo preventive of ITCs against several types of cancer cell lines. We have also discussed the molecular interaction(s) of the antagonistic effect of BITC, PEITC and SFN with Nrf2 and NF-κB to prevent cancer.

Recent progress in natural dietary non-phenolic bioactives on cancers metastasis

From several decades ago to now, cancer continues to be the leading cause of death worldwide, and metastasis is the major cause of cancer-related deaths. For health benefits, there is a great desire to use non-chemical therapy such as nutraceutical supplementation to prevent pathology development. Over 10,000 different natural bioactives or phytochemicals have been known that possessing potential preventive or supplementary effects for various diseases including cancer. Previously, the in vitro and in vivo anti-invasive and anti-metastatic activities of phenolic acids, monophenol, polyphenol and their derivatives and flavonoids and their derivatives have been reviewed. However, a vast number of natural dietary compounds other than phenolics have been demonstrated to potentially possess the ability to inhibit the invasion and metastasis of various cancers. In this review, we summarize the studies in recent decade on in vitro and in vivo effects and molecular mechanisms of natural bioactives, excluding the phenolics in food, in cancer invasion and metastasis. By combining this review of non-phenolics with the previous phenolics reviews, the puzzle for the contribution of natural dietary bioactives on cancer invasive or/and metastatic progress will be almost complete and more clear.

PIM Kinases and Their Relevance to the PI3K/AKT/mTOR Pathway in the Regulation of Ovarian Cancer

Ovarian cancer is a medical term that includes a number of tumors with different molecular biology, phenotypes, tumor progression, etiology, and even different diagnosis. Some specific treatments are required to address this heterogeneity of ovarian cancer, thus molecular characterization may provide an important tool for this purpose. On a molecular level, proviral-integration site for Moloney-murine leukemia virus (PIM) kinases are over expressed in ovarian cancer and play a vital role in the regulation of different proteins responsible for this tumorigenesis. Likewise, the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is also a central regulator of the ovarian cancer. Interestingly, recent research has linked the PIM kinases to the PI3K/AKT/mTOR pathway in several types of cancers, but their connection in ovarian cancer has not been studied yet. Once the exact relationship of PIM kinases with the PI3K/AKT/mTOR pathway is acquired in ovarian cancer, it will hopefully provide effective treatments on a molecular level. This review mainly focuses on the role of PIM kinases in ovarian cancer and their interactions with proteins involved in its progression. In addition, this review suggests a connection between the PIM kinases and the PI3K/AKT/mTOR pathway and their parallel mechanism in the regulation of ovarian cancer.

Allyl Isothiocyanate Exhibits No Anticancer Activity in MDA-MB-231 Breast Cancer Cells

It was reported recently that allyl isothiocyanate (AITC) could inhibit various types of cancer cell growth. In the present study, we further investigated whether AITC could inhibit the growth of human breast cancer cells. Unexpectedly, we found that AITC did not inhibit, rather slightly promoted, the proliferation of MDA-MB-231 breast cancer cells, although it did have inhibitory effect on MCF-7 breast cancer cells. Cytofluorimetric analysis revealed that AITC (10 µM) did not induce apoptosis and cell cycle arrest in MDA-MB-231 cells. In addition, AITC significantly (p < 0.05) increased the expression of BCL-2 and mTOR genes and Beclin-1 protein in MDA-MB-231 cells. No significant changes in expression of PRKAA1 and PER2 genes, Caspase-8, Caspase-9, PARP, p-mTOR, and NF-κB p65 proteins were observed in these AITC-treated cells. Importantly, AITC displayed cytotoxic effect on MCF-10A human breast epithelial cell line. These observations suggest that AITC may not have inhibitory activity in MDA-MB-231 breast cancer cells. This in vitro study warrants more preclinical and clinical studies on the beneficial and harmful effects of AITC in healthy and cancer cells.