Thymoquinone inhibits the metastasis of renal cell cancer cells by inducing autophagy via AMPK/mTOR signaling pathway

Thymoquinone Nanoparticles (TQ-NPs) in Kidney Toxicity Induced by Ehrlich Ascites Carcinoma (EAC): An In Vivo Study

Background

Cisplatin (Cis) is potent chemotherapy used to treating already many different types of cancer; however, it is found to correlate with nephrotoxicity and other adverse health consequences. Thymoquinone (TQ) is an antioxidant and anti-inflammatory molecule that may defend against the consequences of different chemotherapies. Thymoquinone uses, although, are negatively impacted by its weak solubility and inadequate biological availability.

Objectives

This investigation examined the efficacy of a new nanoparticle (NP) absorbing TQ in an Ehrlich Ascites Carcinoma (EAC) mice model to address its low solubility, enhance its bioavailability, and protect against Cis-induced nephrotoxicity.

Methods

Following 4 treatment groups were included in this research: (1) control, (2) EAC, (3) EAC + Cis + Thymoquinone nanoparticle (TQ-NP) treated, and (4) EAC + Cis-treated.

Results

The study revealed that TQ-NP was efficacious in avoiding Cis-induced kidney problems in EAC mice, as well as restoring kidney function and pathology. Thymoquinone nanoparticle considerably reduced Cis-induced oxidative damage in renal tissue by augmenting antioxidant levels. According to tumor weight and histological investigation results, TQ-NP did not impair Cis's anticancer efficacy.

Conclusion

Thymoquinone nanoparticle might be used as a potential drug along with Cis anticancer therapy to reduce nephrotoxicity and other side effects while maintaining Cis anticancer properties.

Thymoquinone: An Effective Natural Compound for Kidney Protection

Kidney disease is a common health problem worldwide. Acute or chronic injuries may interfere with kidney functions, eventually resulting in irreversible kidney damage. A number of recent studies have shown that the plant-derived natural products have an extensive potential for renal protection. Thymoquinone (TQ) is an essential compound derived from Nigella Sativa (NS), which is widely applied in the Middle East as a folk medicine. Previous experiments have demonstrated that TQ has a variety of potential pharmacological effects, including anti-oxidant, antibacterial, antitumor, immunomodulatory, and neuroprotective activities. In particular, the prominent renal protective efficacy of TQ has been demonstrated in both in vivo and in vitro experiments. TQ can prevent acute kidney injuries from various xenobiotics through anti-oxidation, anti-inflammatory, and anti-apoptosis effects. In addition, TQ exhibited significant pharmacological effects on renal cell carcinoma, renal fibrosis, and urinary calculi. The essential mechanisms involve scavenging ROS and increasing anti-oxidant activity, decreasing inflammatory mediators, inducing apoptosis, and inhibiting migration and invasion. The purpose of this review is to conclude the pharmacological effects and the potential mechanisms of TQ in renal protection, shedding new light on the exploration of medicinal phyto-protective agents targeting kidneys.

Computational and in vitro analyses on synergistic effects of paclitaxel and thymoquinone in suppressing invasive breast cancer cells

BACKGROUND

In the present experiment, we evaluated the impact of thymoquinone (TQ) and paclitaxel (PTX) treatment on MDA-MB-231 cell line growth inhibition via controlling apoptosis/autophagy.

MATERIALS AND RESULTS

MDA-MB-231cells were exposed to PTX (0, 25, 50, 75, and 100 nM), TQ (0, 25, 50, 75, and 100 µM), and combinations for 48 h. After the MTT assessment, dose-response curves and IC50 values were calculated, and the combination synergism was evaluated using the Compusyn software. Following the treatment with PTX, TQ, and combinations at IC50 doses, the expression of apoptosis and autophagy genes was assessed in cells. The GraphPad Prism program was used to analyze the data, and Tukey's test at p < 0.05 was then run. PTX, TQ, and their combinations inhibited MDA-MB-231cell proliferation and viability dose-dependently. TQ reduced the effective concentration (IC50) of PTX in co-treatment groups. PTX and TQ showed antagonistic effects when cell proliferation declined above 70%. Antagonistic effects shifted into additive and synergistic effects upon increasing PTX concentration, indicated by diminished cell proliferation below 70%. PTX-TQ co-treatment significantly enhanced P53 and BAX expression while reducing Bcl-2 expression. Also, their combination increased Beclin-1, ATG-5, and ATG-7 expression in treated cells.

CONCLUSION

Effective concentrations of TQ and PTX had synergic effects and inhibited breast cancer cells via prompting apoptosis and autophagy in vitro.

CASC19: An Oncogenic Long Non-coding RNA in Different Cancers

A 324 bp lncRNA called CASC19 is found on chromosome 8q24.21. Recent research works have revealed that CASC19 is involved in the prognosis of tumors and related to the regulation of the radiation tolerance mechanisms during tumor radiotherapy (RT). This review sheds light on the changes and roles that CASC19 plays in many tumors and diseases, such as nasopharyngeal carcinoma (NPC), cervical cancer, colorectal cancer (CRC), non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (ccRCC), gastric cancer (GC), pancreatic cancer (PC), hepatocellular carcinoma (HCC), glioma, and osteoarthritis (OA). CASC19 provides a new strategy for targeted therapy, and the regulatory networks of CASC19 expression levels play a key role in the occurrence and development of tumors and diseases. In addition, the expression level of CASC19 has predictive roles in the prognosis of some tumors and diseases, which has major implications for clinical diagnoses and treatments. CASC19 is also unique in that it is a key gene affecting the efficacy of RT in many tumors, and its expression level plays a decisive role in improving the success rate of treatments. Further research is required to determine the precise process by which CASC19 causes changes in diseased cells in some tumors and diseases.

JS-K activates G2/M checkpoints through the DNA damage response and induces autophagy via CAMKKβ/AMPKα/mTOR pathway in bladder cancer cells

The aim of this study was to investigate the effects of JS-K, a nitric oxide donor prodrug, on DNA damage and autophagy in bladder cancer (BCa) cells and to explore the potential related mechanisms. Through detecting proliferation viability, cell morphology observation and colony formation assay low concentrations of JS-K significantly inhibited BCa growth while having no effect on normal cells. JS-K induced an increase in the level of DNA damage protein γH2AX and a decrease in the level of DNA damage repair-related proteins PCNA and RAD51 in BCa cells, indicating that JS-K can induce DNA damage in BCa cells and inhibit DNA damage repair. JS-K induced G2/M phase block and calcium overload using flow cytometry analysis. Moreover, we also investigated the levels of cell G2/M cycle checkpoint-related protein and autophagy-associated protein by western blot. The results of our study demonstrated that JS-K induced BCa cells G2/M phase arrest due to upregulating proteins related to DNA damage-related G2/M checkpoint activation (p-ATM, p-ATR, p-Chk1, p-Chk2, and p-Cdc2) and down-regulation of Cyclin B1 protein. In addition, our study demonstrated that JS-K-induced autophagy in BCa cells was related to the CAMKKβ/AMPKα/mTOR pathway.

PLCL1 suppresses tumour progression by regulating AMPK/mTOR-mediated autophagy in renal cell carcinoma

Autophagy has been increasingly recognized as a critical regulatory mechanism in the maintenance of cellular homeostasis. A previous study showed that phospholipase C-like protein 1 (PLCL1) is associated with lipid metabolism in renal cell carcinoma (RCC). However, it is unclear whether PLCL1 regulates autophagy, thereby influencing the progression of RCC. Bioinformatics analysis of five microarray datasets revealed that expression of PLCL1 is decreased in tumours and is positively correlated with prognosis in RCC patients. Three independent public datasets, clinical RCC tissues and RCC cell lines, were validated using real-time qPCR, western blotting and immunohistochemistry. Using wound healing and transwell assays, we observed that elevated PLCL1 levels decreased the migratory distance and the invasive number of 786-O and ACHN cells, but PLCL1 knockdown reversed these changes in 769P cell lines compared to those in controls. The results of flow cytometry analysis indicated that PLCL1 promotes apoptosis. Moreover, transcriptional analysis based on stable overexpression of PLCL1 in 786-O cells revealed that PLCL1 is related to autophagy, and western blotting and autophagic experimental results further verified these findings. Mechanistic investigations confirmed that PLCL1 activates the AMPK/mTOR pathway and interacts with decidual protein induced by progesterone (DEPP). Collectively, our data suggest that PLCL1 functions as a suppressor of RCC progression by activating the AMPK/mTOR pathway, interacting with DEPP, initiating autophagy and inducing apoptosis. PLCL1 may be a promising therapeutic target for the diagnosis and treatment of ccRCC patients.

Therapeutic strategies targeting AMPK-dependent autophagy in cancer cells

Macroautophagy is a health-modifying process of engulfing misfolded or aggregated proteins or damaged organelles, coating these proteins or organelles into vesicles, fusion of vesicles with lysosomes to form autophagic lysosomes, and degradation of the encapsulated contents. It is also a self-rescue strategy in response to harsh environments and plays an essential role in cancer cells. AMP-activated protein kinase (AMPK) is the central pathway that regulates autophagy initiation and autophagosome formation by phosphorylating targets such as mTORC1 and unc-51 like activating kinase 1 (ULK1). AMPK is an evolutionarily conserved serine/threonine protein kinase that acts as an energy sensor in cells and regulates various metabolic processes, including those involved in cancer. The regulatory network of AMPK is complicated and can be regulated by multiple upstream factors, such as LKB1, AKT, PPAR, SIRT1, or noncoding RNAs. Currently, AMPK is being investigated as a novel target for anticancer therapies based on its role in macroautophagy regulation. Herein, we review the effects of AMPK-dependent autophagy on tumor cell survival and treatment strategies targeting AMPK.

Cuproptosis enhances docetaxel chemosensitivity by inhibiting autophagy via the DLAT/mTOR pathway in prostate cancer

Cuproptosis, a newly discovered programmed cell death induced by copper ions, is associated with the progression and drug resistance of various tumors. Docetaxel plays a vital role as a first-line chemotherapeutic agent for advanced prostate cancer; however, most patients end up with prostate cancer progression because of inherent or acquired resistance. Herein, we examined the role of cuproptosis in the chemotherapeutic resistance of prostate cancer to docetaxel. We treated prostate cancer cell lines with elesclomol-CuCl2 , as well as with docetaxel. We performed analyses of CCK8, colony formation tests, cell cycle flow assay, transmission electron microscopy, and mTOR signaling in treated cells, and treated a xenograft prostate cancer model with elesclomol-CuCl2 and docetaxel in vivo, and performed immunohistochemistry and Western blotting analysis in treated tumors. We found that elesclomol-CuCl2 could promote cell death and enhance chemosensitivity to docetaxel. Elesclomol-CuCl2 induced cell death and inhibited the growth of prostate cancer cells relying on copper ions-induced cuproptosis, not elesclomol. In addition, dihydrolipoamide S-acetyltransferase (DLAT) was involved in cuproptosis-enhanced drug sensitivity to docetaxel. Mechanistically, upregulated DLAT by cuproptosis inhibited autophagy, promoted G2/M phase retention of cells, and enhanced the sensitivity to docetaxel chemotherapy in vitro and in vivo via the mTOR signaling pathway. Our findings demonstrated that the cuproptosis-regulated DLAT/mTOR pathway inhibited autophagy and promoted cells in G2/M phase retention, thus enhancing the chemosensitivity to docetaxel. This discovery may provide an effective therapeutic option for treating advanced prostate cancer by inhibiting the chemotherapeutic resistance to docetaxel.

Natural Compounds Derived from Plants on Prevention and Treatment of Renal Cell Carcinoma: A Literature Review

Renal cell carcinoma (RCC) accounts for roughly 85% of all malignant kidney cancer. Therapeutic options for RCC have expanded rapidly over the past decade. Targeted therapy and immunotherapy have ushered in a new era of the treatment of RCC, which has facilitated the outcomes of RCC. However, the related adverse effects and drug resistance remain an urgent issue. Natural compounds are optional strategies to reduce mobility. Natural compounds are favored by clinicians and researchers due to their good tolerance and low economic burden. Many studies have explored the anti-RCC activity of natural products and revealed relevant mechanisms. In this article, the chemoprevention and therapeutic potential of natural compounds is reviewed and the mechanisms regarding natural compounds are explored.

Thymoquinone inhibits lung cancer stem cell properties via triggering YAP degradation

Due to the characteristics of high recurrence and metastasis, it is still difficult to cure lung cancer. Cancer stem cells (CSCs) are a group of tumor cells with self-renewal ability and differentiation potential, which are responsible for lung cancer recurrence. Therefore, targeting CSCs may provide a new strategy for lung cancer treatment. Thymoquinone (TQ), the main active ingredient isolated from black seed oil, has shown significant anti-cancer effects in various cancers. However, the effect of TQ on lung cancer stem cells (LCSCs) has never been clarified. In the present study, we successfully separated and enriched lung cancer tumorsphere cells. Our data showed that TQ significantly inhibited the stem-like properties of LCSCs. In addition, we found TQ promoted Yes-associated protein (YAP) phosphorylation and ubiquitination, and the inhibitory effects of TQ on LCSCs could be enhanced by silencing YAP. Taken together, these results suggest that TQ, functions by targeting YAP, may be a potential therapeutic agent against lung cancer.

Natural and Synthetic Anticancer Epidrugs Targeting the Epigenetic Integrator UHRF1

Cancer is one of the leading causes of death worldwide, and its incidence and mortality are increasing each year. Improved therapeutic strategies against cancer have progressed, but remain insufficient to invert this trend. Along with several other risk factors, abnormal genetic and epigenetic regulations play a critical role in the initiation of cellular transformation, as well as tumorigenesis. The epigenetic regulator UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is a multidomain protein with oncogenic abilities overexpressed in most cancers. Through the coordination of its multiple domains and other epigenetic key players, UHRF1 regulates DNA methylation and histone modifications. This well-coordinated dialogue leads to the silencing of tumor-suppressor genes (TSGs) and facilitates tumor cells' resistance toward anticancer drugs, ultimately promoting apoptosis escape and uncontrolled proliferation. Several studies have shown that the downregulation of UHRF1 with natural compounds in tumor cells induces the reactivation of various TSGs, inhibits cell growth, and promotes apoptosis. In this review, we discuss the underlying mechanisms and the potential of various natural and synthetic compounds that can inhibit/minimize UHRF1's oncogenic activities and/or its expression.

Thymoquinone induces apoptosis and protective autophagy in gastric cancer cells by inhibiting the PI3K/Akt/mTOR pathway

Gastric cancer (GC) is often diagnosed in the advanced stages with a poor prognosis. Thymoquinone (TQ) is known for its antitumor activity; however, the specific mechanism in GC remains unknown. In our study, TQ inhibited GC cell proliferation and induced apoptosis and autophagy in a concentration-dependent manner. Transmission electron microscopy showed increased autophagosome formation in GC cells treated with TQ. Meanwhile, the LC3B puncta and LC3BII protein levels were significantly increased in GC cells, while p62 expression was significantly decreased. The autophagy inhibitor, Bafilomycin A1 enhanced TQ-inhibited proliferation and TQ-induced apoptosis, suggesting that TQ-induced autophagy has a protective effect on GC cells. Furthermore, TQ decreased the phosphorylation levels of phosphatidylinositol-4,5-bisphosphate 3 kinase (PI3K), protein kinase B (Akt), and mechanistic target of rapamycin (mTOR). The PI3K agonist partially rescued TQ-induced autophagy and apoptosis. Finally, in vivo experiments showed that TQ could inhibit tumor growth and promote apoptosis and autophagy. This study provides new insights into the specific mechanism for the anti-GC effect of TQ. TQ inhibits the proliferation of GC cells and induces apoptosis and protective autophagy by inhibiting the PI3K/Akt/mTOR pathway. The results suggest that the combination of TQ and autophagy inhibitors might be a potential chemotherapeutic strategy for GC.

Thymoquinone Enhances Apoptosis of K562 Chronic Myeloid Leukemia Cells through Hypomethylation of SHP-1 and Inhibition of JAK/STAT Signaling Pathway

The epigenetic silencing of tumor suppressor genes (TSGs) is critical in the development of chronic myeloid leukemia (CML). SHP-1 functions as a TSG and negatively regulates JAK/STAT signaling. Enhancement of SHP-1 expression by demethylation provides molecular targets for the treatment of various cancers. Thymoquinone (TQ), a constituent of Nigella sativa seeds, has shown anti-cancer activities in various cancers. However, TQs effect on methylation is not fully clear. Therefore, the aim of this study is to assess TQs ability to enhance the expression of SHP-1 through modifying DNA methylation in K562 CML cells. The activities of TQ on cell cycle progression and apoptosis were evaluated using a fluorometric-red cell cycle assay and Annexin V-FITC/PI, respectively. The methylation status of SHP-1 was studied by pyrosequencing analysis. The expression of SHP-1, TET2, WT1, DNMT1, DNMT3A, and DNMT3B was determined using RT-qPCR. The protein phosphorylation of STAT3, STAT5, and JAK2 was assessed using Jess Western analysis. TQ significantly downregulated the DNMT1 gene, DNMT3A gene, and DNMT3B gene and upregulated the WT1 gene and TET2 gene. This led to hypomethylation and restoration of SHP-1 expression, resulting in inhibition of JAK/STAT signaling, induction of apoptosis, and cell cycle arrest. The observed findings imply that TQ promotes apoptosis and cell cycle arrest in CML cells by inhibiting JAK/STAT signaling via restoration of the expression of JAK/STAT-negative regulator genes.

Molecular mechanisms and signaling pathways of black cumin (Nigella sativa) and its active constituent, thymoquinone: a review

BACKGROUND

Nigella sativa and its main bioactive ingredient, thymoquinone, exhibit various pharmacological activities, including neuroprotective, nephroprotective, cardioprotective, gastroprotective, hepatoprotective, and anti-cancer effects. Many studies have been conducted trying to elucidate the molecular signaling pathways that mediate these diverse pharmacological properties of N. sativa and thymoquinone. Accordingly, the goal of this review is to show the effects of N. sativa and thymoquinone on different cell signaling pathways.

METHODS

The online databases Scopus, PubMed and Web of Science were searched to identify relevant articles using a list of related keywords such as Nigella sativa, black cumin, thymoquinone, black seed, signal transduction, cell signaling, antioxidant, Nrf2, NF-κB, PI3K/AKT, apoptosis, JAK/STAT, AMPK, MAPK, etc. Only articles published in the English language until May 2022 were included in the present review article.

RESULTS

Studies indicate that N. sativa and thymoquinone improve antioxidant enzyme activities, effectively scavenges free radicals, and thus protect cells from oxidative stress. They can also regulate responses to oxidative stress and inflammation via Nrf2 and NF-κB pathways. N. sativa and thymoquinone can inhibit cancer cell proliferation through disruption of the PI3K/AKT pathway by upregulating phosphatase and tensin homolog. Thymoquinone can modulate reactive oxygen species levels in tumor cells, arrest the cell cycle in the G2/M phase as well as affect molecular targets including p53, STAT3 and trigger the mitochondrial apoptosis pathway. Thymoquinone, by adjusting AMPK, can regulate cellular metabolism and energy hemostasis. Finally, N. sativa and thymoquinone can elevate brain GABA content, and thus it may ameliorate epilepsy.

CONCLUSIONS

Taken together, the improvement of antioxidant status and prevention of inflammatory process by modulating the Nrf2 and NF-κB signaling and inhibition of cancer cell proliferation through disruption of the PI3K/AKT pathway appear to be the main mechanisms involved in different pharmacological properties of N. sativa and thymoquinone.

Comprehensive Analysis of the Roles of Fatty Acid Transport Related Proteins in Clear Cell Renal Cell Carcinoma

OBJECTIVE

This study aimed to explore the clinical significance of fatty acid transport-related protein (FATRP) in patients with clear cell renal cell carcinoma(ccRCC).

METHODS

RNA-seq data and corresponding clinical data of ccRCC were obtained from TCGA data portal. Seventeen key FATRP genes were comprehensively investigated using bioinformatics approaches to systematically investigate their expression patterns in ccRCC. In addition, the correlation between the expression levels of these genes and clinicopathological features in ccRCC was further explored.

RESULTS

Among the 17 key FATRP genes, only FABP5, FABP6, and FABP7 could be regarded as ideal biomarkers for ccRCC, as they were highly expressed in ccRCC tumor tissues, and positively correlates with tumor progression and poor prognosis. FABP6 had the highest copy number variations (CNV) events (63.07%), and ccRCC patients with FABP6 amplification had a better prognosis than the unaltered group. DNA methylation levels of FABP6 and FABP7 were downregulated in ccRCC tumor tissues compared to those in normal tissues. FABP5 showed the opposite results. Moreover, a novel four FATRP gene (FABP1, FABP5, FABP7, FATP2) and three clinical parameter (age, stage, and grade) prediction model was constructed and that comprised a significant independent prognostic signature.

CONCLUSIONS

Only a few FATRP genes are upregulated in ccRCC tumor tissue, and positively correlate with tumor progression and poor prognosis. The accuracy of a single gene of these FATRP genes as predictors of progression and prognosis of ccRCC is limited. The performance of the novel prediction model proposed by this study was much better than that of any single gene.

The healing effects of thymoquinone on experimentally induced traumatic tendinopathy in rabbits

OBJECTIVES

Thymoquinone is a major bioactive compound present in the black seeds of the Nigella sativa. Tendon injuries are almost 50% of all musculoskeletal injuries. The recovery of tendon after surgery has become a significant challenge in orthopedics.

DESIGN

The purpose of this study was to investigate the healing effect of thymoquinone injections in 40 New Zealand rabbits tendon traumatic models.

MATERIALS AND METHODS

Tendinopathy was induced by trauma using surgical forceps on the Achilles tendon. Animals were randomly divided into 4 groups: (1) normal saline injection (control), (2) DMSO injection, (3) thymoquinone 5% w/w injection, and (4) thymoquinone 10% w/w injection. Forty-two days after surgery, biochemical and histopathological evaluations were done, and biomechanical evaluation was conducted 70 days after surgery.

RESULTS

Breakpoint and yield points in treatment groups were significantly higher compared to control and DMSO groups. Hydroxyproline content in the 10% thymoquinone receiving group was higher than all groups. Edema and hemorrhage in the histopathological evaluation were significantly lower in the thymoquinone 10% and thymoquinone 5% receiving groups compared to control and DMSO groups. Collagen fibers, collagen fibers with fibrocytes, and collagen fibers with fibroblasts were significantly higher in the thymoquinone 10% and thymoquinone 5% receiving groups compared to control groups.

CONCLUSIONS

Thymoquinone injection in the tendon in the concentration of 10% w/w is a simple and low-cost healing agent that could enhance mechanical and collagen synthesis in traumatic tendinopathy models in rabbit.

Antrodia camphorata and coenzyme Q0 , a novel quinone derivative of Antrodia camphorata, impede HIF-1α and epithelial-mesenchymal transition/metastasis in human glioblastoma cells

Antrodia camphorata (AC) and Coenzyme Q₀ (CoQ₀ ), a novel quinone derivative of AC, exhibits antitumor activities. The present study evaluated EMT/metastasis inhibition and autophagy induction aspects of AC and CoQ₀ in human glioblastoma (GBM8401) cells. Our findings revealed that AC treatment (0-150 μg/mL) hindered tumor cell proliferation and migration/invasion in GBM8401 cells. Notably, AC treatment inhibited HIF-1α and EMT by upregulating epithelial marker protein E-cadherin while downregulating mesenchymal proteins Twist, Slug, Snail, and β-catenin. There was an appearance of the autophagy markers LC3-II and p62/SQSTM1, while ATG4B was downregulated by AC treatment. We also found that CoQ₀ (0-10 μM) could inhibit migration and invasion in GBM8401 cells. In particular, E-cadherin was elevated and N-cadherin, Vimentin, Twist, Slug, and Snail, were reduced upon CoQ₀ treatment. In addition, MMP-2/-9 expression and Wnt/β-catenin pathways were downregulated. Furthermore, autophagy inhibitors 3-MA or CQ reversed the CoQ₀ -elicited suppression of migration/invasion and metastasis-related proteins (Vimentin, Snail, and β-catenin). Results suggested autophagy-mediated antiEMT and antimetastasis upon CoQ₀ treatment. CoQ₀ inhibited HIF-1α and metastasis in GBM8401 cells under normoxia and hypoxia. HIF-1α knockdown using siRNA accelerated CoQ₀ -inhibited migration. Finally, CoQ₀ exhibited a prolonged survival rate in GBM8401-xenografted mice. Treatment with Antrodia camphorata/CoQ₀ inhibited HIF-1α and EMT/metastasis in glioblastoma.

AKG induces cell apoptosis by inducing reactive oxygen species-mediated endoplasmic reticulum stress and by suppressing PI3K/AKT/mTOR-mediated autophagy in renal cell carcinoma

BACKGROUND

Alpha-ketoglutarate (AKG) or 2-oxoglutarate is a key substance in the tricarboxylic acid cycle (TCA) and has been known to play an important role in cancerogenesis and tumor progression. Renal cell carcinoma (RCC) is the most common type of kidney cancer, and it has a high mortality rate. Autophagy is a phenomenon of self-digestion, and its significance in tumor genesis and progression remains debatable. However, the mechanisms underlying how AKG regulates autophagy in RCC remain unknown. Thus, the purpose of this study was to assess the therapeutic efficacy of AKG and its molecular mechanisms.

METHODS

RCC cell lines 786O and ACHN were treated with varying doses of AKG for 24 h. CCK-8, Transwell, and scratch wound healing assays were utilized to evaluate the role of AKG in RCC cells. Autophagy protein and PI3K/AKT/mTOR pathway protein levels were analyzed by Western blot.

RESULTS

AKG inhibited the proliferation of RCC cells 786O and ACHN in a dose-dependent manner according to the CCK-8 assay. In addition, flow cytometry and Western blot analysis revealed that AKG dose-dependently triggered apoptosis and autophagy in RCC cells. By promoting cell apoptosis and autophagy, AKG dramatically suppressed tumor growth. Mechanistically, AKG induces autophagy by promoting ROS generation and inhibiting the PI3K/AKT/mTOR pathway.

CONCLUSIONS

The anti-tumor effect of AKG promotes autophagy in renal cancer cells via mediating ROS-PI3K/Akt/mTOR, and may be used as a potential anticancer drug for kidney cancer.

Chemopreventive Efficacy of Thymoquinone in Chemically Induced Urinary Bladder Carcinogenesis in Rat

The effects of thymoquinone (TQ) in a carcinogen-based models of urinary bladder cancer were evaluated, using 45 male rats in five groups. In negative control ( $n=10$ ), only tap water was given. In positive control ( $n=10$ ), the rats received 0.05% N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in drinking water for 9 weeks. In preventive groups with 25 mg/kg ( $n=10$ ) and 50 mg/kg ( $n=10$ ), oral TQ was concurrently given with 0.05% BBN for 9 weeks and continued for one more week after cessation of BBN. Preventive-treatment group ( $n=5$ ) received 50 mg/kg TQ orally for 20 weeks. Five rats from each group were sequentially sacrificed in two phases: the induction phase at 12th week (except the last group) and the rest in postinduction phase at 20th week. The bladders were examined macroscopically for lesion formation, and the masses were submitted for histopathological evaluation. Markers for total oxidant status (TOS), inflammation (nuclear factor kappa B (NF-κB)), and angiogenesis (vascular endothelial growth factor (VEGF)) were also assessed. There was a reduced number of bladder lesions in the TQ groups versus the carcinogen group at both phases. Histopathological findings demonstrated a significant improvement in the abnormal morphological changes in the urothelium of the TQ-treated groups. Thymoquinone exerted a significant antioxidant and anti-inflammatory effect by a decrease in serum level of TOS and NF-κB at week 12 which was maintained low in phase two at week 20. The serum level of VEGF was also alleviated in the induction phase at week 12 and maintained low in postinduction period. In TQ preventive-treatment approach, a nonsignificant elevation of serum level of TOS and NF-κB and slight reduction in VEGF were observed at the end of the experiment. These data suggest that TQ may be effective in preventing bladder carcinogenesis, and the suggested mechanisms might be related to antioxidant, prooxidant, and anti-inflammatory properties of TQ.

Thymoquinone Inhibits JAK/STAT and PI3K/Akt/ mTOR Signaling Pathways in MV4-11 and K562 Myeloid Leukemia Cells

Constitutive activation of Janus tyrosine kinase-signal transducer and activator of transcription (JAK/STAT) and Phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signaling pathways plays a crucial role in the development of acute myeloid leukemia (AML) and chronic myeloid leukemia (CML). Thymoquinone (TQ), one of the main constituents of Nigella sativa, has shown anti-cancer activities in several cancers. However, the inhibitory effect mechanism of TQ on leukemia has not been fully understood. Therefore, this study aimed to investigate the effect of TQ on JAK/STAT and PI3K/Akt/mTOR pathways in MV4-11 AML cells and K562 CML cells. FLT3-ITD positive MV4-11 cells and BCR-ABL positive K562 cells were treated with TQ. Cytotoxicity assay was assessed using WSTs-8 kit. The expression of the target genes was evaluated using RT-qPCR. The phosphorylation status and the levels of proteins involved in JAK/STAT and PI3K/Akt/mTOR pathways were investigated using Jess western analysis. TQ induced a dose and time dependent inhibition of K562 cells proliferation. TQ significantly downregulated PI3K, Akt, and mTOR and upregulated PTEN expression with a significant inhibition of JAK/STAT and PI3K/Akt/mTOR signaling. In conclusion, TQ reduces the expression of PI3K, Akt, and mTOR genes and enhances the expression of PTEN gene at the mRNA and protein levels. TQ also inhibits JAK/STAT and PI3K/Akt/mTOR pathways, and consequently inhibits proliferation of myeloid leukemia cells, suggesting that TQ has potential anti-leukemic effects on both AML and CML cells.

Renal cell carcinoma management: A step to nano-chemoprevention

Renal cell carcinoma (RCC) is one of the most common kidney cancers, responsible for nearly 90 % of all renal malignancies. Despite the availability of many treatment strategies, RCC still remains to be an incurable disease due to its resistivity towards conventional therapies. Nanotechnology is an emerging field of science that offers newer possibilities in therapeutics including cancer medicine, specifically by targeted delivery of anticancer drugs. Several phytochemicals are known for their anti-cancer properties and have been regarded as chemopreventive agents. However, the hydrophobic nature of many phytochemicals decreases its bioavailability and distribution, thus showing limited therapeutic effect. Application of nanotechnology to enhance chemoprevention is an effective strategy to increase the bioavailability of phytochemicals and thereby its therapeutic efficacy. The present review focuses on the utility of nanotechnology in RCC treatment and chemopreventive agents of RCC. We have also visualized the future prospects of nanomolecules in the prevention and cure of RCC.

Anticancer and Anti-Metastatic Role of Thymoquinone: Regulation of Oncogenic Signaling Cascades by Thymoquinone

Cancer is a life-threatening and multifaceted disease. Pioneering research works in the past three decades have mechanistically disentangled intertwined signaling networks which play contributory roles in carcinogenesis and metastasis. Phenomenal strides have been made in leveraging our scientific knowledge altogether to a new level of maturity. Rapidly accumulating wealth of information has underlined a myriad of transduction cascades which can be pharmaceutically exploited for cancer prevention/inhibition. Natural products serve as a treasure trove and compel interdisciplinary researchers to study the cancer chemopreventive roles of wide-ranging natural products in cell culture and preclinical studies. Experimental research related to thymoquinone has gradually gained momentum because of the extra-ordinary cancer chemopreventive multifunctionalities of thymoquinone. In this mini-review, we provide an overview of different cell signaling cascades reported to be regulated by thymoquinone for cancer chemoprevention. Essentially, thymoquinone efficacy has also been notably studied in animal models, which advocates for a rationale-based transition of thymoquinone from the pre-clinical pipeline to clinical trials.

Combinatorial effect of thymoquinone with chemo agents for tumor therapy

BACKGROUND

Most chemotherapeutics used in cancer therapies exhibit considerable side effects to the patients. Thus, developing new chemo agents to treat cancer patients with minimal toxic and side effects is urgently needed. Recently, the combination of different chemotherapeutics has become a promising strategy to treat malignancies. Thymoquinone (TQ) is a primary bioactive compound derived from the folk medicinal plant Nigella sativa, which has been found an antitumor, chemopreventive and chemopotentiating agent against human neoplastic diseases.

PURPOSE

We briefly summarize the current research of the biomolecular mechanisms of TQ and evaluate the existing literature on TQ adjuvant therapies against various cancers.

METHOD

The data in this review were gathered by several search engines including, Google Scholar, PubMed and ScienceDirect. We highlighted and classified the outcomes of both in vitro and in vivo experiments of TQ adjuvant therapies against human cancers and their chemopreventive activities on vital organs.

RESULTS

Several studies have shown that TQ synergistically potentiated the antitumor activity of numerous chemo agents against human neoplastic disease, including lung, breast, liver, colorectal, skin, prostate, stomach, bone and blood cancers. TQ also acted as a chemopreventive agent and reduced the toxicity of many chemo agents to vital organs, such as the heart, liver, kidneys and lungs.

CONCLUSION

In summary, we highly recommend an advanced evaluation of TQ adjuvant therapies at the level of preclinical and clinical trials, which could lead to a novel combinatorial therapy for cancer treatment with low or tolerable adverse effects on patients.

Therapeutic Potential of Certain Terpenoids as Anticancer Agents: A Scoping Review

Cancer is a life-threatening disease and is considered to be among the leading causes of death worldwide. Chemoresistance, severe toxicity, relapse and metastasis are the major obstacles in cancer therapy. Therefore, introducing new therapeutic agents for cancer remains a priority to increase the range of effective treatments. Terpenoids, a large group of secondary metabolites, are derived from plant sources and are composed of several isoprene units. The high diversity of terpenoids has drawn attention to their potential anticancer and pharmacological activities. Some terpenoids exhibit an anticancer effect by triggering various stages of cancer progression, for example, suppressing the early stage of tumorigenesis via induction of cell cycle arrest, inhibiting cancer cell differentiation and activating apoptosis. At the late stage of cancer development, certain terpenoids are able to inhibit angiogenesis and metastasis via modulation of different intracellular signaling pathways. Significant progress in the identification of the mechanism of action and signaling pathways through which terpenoids exert their anticancer effects has been highlighted. Hence, in this review, the anticancer activities of twenty-five terpenoids are discussed in detail. In addition, this review provides insights on the current clinical trials and future directions towards the development of certain terpenoids as potential anticancer agents.

PI3K-AKT Pathway Modulation by Thymoquinone Limits Tumor Growth and Glycolytic Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is the third leading cause of death in men and the fourth in women worldwide and is characterized by deranged cellular energetics. Thymoquinone, an active component from Nigella sativa, has been extensively studied against cancer, however, its role in affecting deregulated cancer metabolism is largely unknown. Further, the phosphoinositide 3-kinase (PI3K) pathway is one of the most activated pathways in cancer and its activation is central to most deregulated metabolic pathways for supporting the anabolic needs of growing cancer cells. Herein, we provide evidence that thymoquinone inhibits glycolytic metabolism (Warburg effect) in colorectal cancer cell lines. Further, we show that such an abrogation of deranged cell metabolism was due, at least in part, to the inhibition of the rate-limiting glycolytic enzyme, Hexokinase 2 (HK2), via modulating the PI3/AKT axis. While overexpression of HK2 showed that it is essential for fueling glycolytic metabolism as well as sustaining tumorigenicity, its pharmacologic and/or genetic inhibition led to a reduction in the observed effects. The results decipher HK2 mediated inhibitory effects of thymoquinone in modulating its glycolytic metabolism and antitumor effects. In conclusion, we provide evidence of metabolic perturbation by thymoquinone in CRC cells, highlighting its potential to be used/repurposed as an antimetabolite drug, though the latter needs further validation utilizing other suitable cell and/or preclinical animal models.

Qingjie Fuzheng Granule Inhibits EMT and Induces Autophagy in Colorectal Cancer via mTOR Signaling Pathways

Qingjie Fuzheng granule (QFG) is a traditional Chinese medicinal formula used extensively as an alternative medicine for cancer treatment, including colorectal cancer (CRC). But its pathological mechanism in CRC is unclear. To study antitumor treatment effects and mechanisms of QFG, we established a CRC HCT-116 xenograft mouse model and assessed QFG on EMT and autophagy progression in vivo. The mice were randomly divided into 2 groups (n = 10 each group) and treated with intragastric administration of 1 g/kg of QFG or saline 6 days a week for 28 days (4 weeks). Body weight was measured every other day with electronic balance. At the end of the treatment, the tumor weight was measured. Immunohistochemical (IHC) and western blot (WB) assay were used to detect the expression level of E-cadherin, N-cadherin, vimentin, and TWIST1 to evaluate the effect of QFG on tumor cell EMT progression. IHC and WB assay were also used to detect the expression level of beclin-1, LC3-II, and p62 to evaluate the effect of QFG on tumor cell autophagy progression. Furthermore, the expression level of relative proteins in mTOR pathway was detected by WB assay to investigate the mechanism of QFG effect on CRC. We discovered that QFG inhibited the rise of tumor weight while it had no effect on mice body weight, which proved that QFG could inhibit CRC growth progression without significant side effects in vivo. In addition, QFG treatment inhibited EMT and induced autophagy progression in CRC tumor cells, including that QFG upregulated the expression of E-cadherin, beclin-1, and LC3-II, but downregulated the expression of N-cadherin, vimentin, TWIST1, and p62. And, QFG decreased the ratio of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, but increased the ratio of p-AMPK/AMPK. All findings from this research proved that QFG can induce autophagy and inhibit EMT progression in CRC via regulating the mTOR signaling pathway.

TQFL12, a novel synthetic derivative of TQ, inhibits triple-negative breast cancer metastasis and invasion through activating AMPK/ACC pathway

Thymoquinone (TQ) has been reported as an anti‐tumour drug widely studied in various tumours, and its mechanism and effect of which has become a focus of current research. However, previous studies from our laboratory and other groups found that TQ showed weak anti‐tumour effects in many cancer cell lines and animal models. Therefore, it is necessary to modify and optimize the structure of TQ to obtain new chemical entities with high efficiency and low toxicity as candidates for development of new drugs in treating cancer. Therefore, we designed and synthesized several TQ derivatives. Systematic analysis, including in vitro and in vivo, was conducted on a panel of triple‐negative breast cancer (TNBC) cells and mouse model to demonstrate whether TQFL12, a new TQ derivative, is more efficient than TQ. We found that the anti‐proliferative effect of TQFL12 against TNBC cells is significantly stronger than TQ. We also demonstrated TQFL12 affects different aspects in breast cancer development including cell proliferation, migration, invasion and apoptosis. Moreover, TQFL12 inhibited tumour growth and metastasis in cancer cell–derived xenograft mouse model, with less toxicity compared with TQ. Finally, mechanism research indicated that TQFL12 increased AMPK/ACC activity by stabilizing AMPKα, while molecular docking supported the direct interaction between TQFL12 and AMPKα. Taken together, our findings suggest that TQFL12, as a novel chemical entity, possesses a better inhibitory effect on TNBC cells and less toxicity in both in vitro and in vivo studies. As such, TQFL12 could serve as a potential therapeutic agent for breast cancer.

Erk phosphorylation reduces the thymoquinone toxicity in human hepatocarcinoma

Although enormous achievements have been made in targeted molecular therapies against hepatocellular carcinoma (HCC), the treatments can only prolong the life of patients with extrahepatic metastases. We evaluated thymoquinone (TQ), a compound from Nigella sativa Linn., for its anti-cancer effect on SK-Hep1 cells and HCC-xenograft nude mice. TQ effectively triggered cell death    and activated p38 and extracellular signal-regulated kinases (Erk) pathways up to 24 h after treatment in cells. TQ-induced cell death was reversed by p38 inhibitor; however, it was enhanced by si-Erk. The caspase3 activation and TUNEL assay revealed a stronger toxic effect upon co-treatment with TQ and si-Erk. Our study suggested that phosphorylation of p38 in SK-Hep1 cells constituted the major factor leading to cell apoptosis, whereas phosphorylation of Erk led to drug resistance. Furthermore, TQ therapeutic effect was improved upon Erk inhibition in HCC-xenograft nude mice. TQ could present excellent anti-HCC potential under suitable p-Erk inhibiting conditions.

Targeting Autophagy with Natural Products as a Potential Therapeutic Approach for Cancer

Macro-autophagy (autophagy) is a highly conserved eukaryotic intracellular process of self-digestion caused by lysosomes on demand, which is upregulated as a survival strategy upon exposure to various stressors, such as metabolic insults, cytotoxic drugs, and alcohol abuse. Paradoxically, autophagy dysfunction also contributes to cancer and aging. It is well known that regulating autophagy by targeting specific regulatory molecules in its machinery can modulate multiple disease processes. Therefore, autophagy represents a significant pharmacological target for drug development and therapeutic interventions in various diseases, including cancers. According to the framework of autophagy, the suppression or induction of autophagy can exert therapeutic properties through the promotion of cell death or cell survival, which are the two main events targeted by cancer therapies. Remarkably, natural products have attracted attention in the anticancer drug discovery field, because they are biologically friendly and have potential therapeutic effects. In this review, we summarize the up-to-date knowledge regarding natural products that can modulate autophagy in various cancers. These findings will provide a new position to exploit more natural compounds as potential novel anticancer drugs and will lead to a better understanding of molecular pathways by targeting the various autophagy stages of upcoming cancer therapeutics.

Therapeutic perspectives of the black cumin component thymoquinone: A review

The dietary phytochemical thymoquinone (TQ), belonging to the family of quinones, mainly obtained from the black and angular seeds of Nigella sativa, is one of the promising monoterpenoid hydrocarbons, which has been receiving massive attention for its therapeutic potential and pharmacological properties. It plays an important role as a chemopreventive and therapeutic agent in the treatment of various diseases and illnesses. The aim of this review is to present a summary of the most recent literature pertaining to the use of TQ for the prevention and treatment of various diseases along with possible mechanisms of action, and the potential use of this natural product as a complementary or alternative medicine. Research findings indicated that TQ exhibits numerous pharmacological activities including antioxidant, anti-inflammatory, cardioprotective, hepatoprotective, antidiabetic, neuroprotective, and anticancer, among others. Conclusions of this review on the therapeutic aspects of TQ highlight the medicinal and folk values of this compound against various diseases and ailments. In short, TQ could be a novel drug in clinical trials, as we hope.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Recent Findings on Thymoquinone and Its Applications as a Nanocarrier for the Treatment of Cancer and Rheumatoid Arthritis

Cancer causes a considerable amount of mortality in the world, while arthritis is an immunological dysregulation with multifactorial pathogenesis including genetic and environmental defects. Both conditions have inflammation as a part of their pathogenesis. Resistance to anticancer and disease-modifying antirheumatic drugs (DMARDs) happens frequently through the generation of energy-dependent transporters, which lead to the expulsion of cellular drug contents. Thymoquinone (TQ) is a bioactive molecule with anticancer as well as anti-inflammatory activities via the downregulation of several chemokines and cytokines. Nevertheless, the pharmacological importance and therapeutic feasibility of thymoquinone are underutilized due to intrinsic pharmacokinetics, including short half-life, inadequate biological stability, poor aqueous solubility, and low bioavailability. Owing to these pharmacokinetic limitations of TQ, nanoformulations have gained remarkable attention in recent years. Therefore, this compilation intends to critically analyze recent advancements in rheumatoid arthritis and cancer delivery of TQ. This literature search revealed that nanocarriers exhibit potential results in achieving targetability, maximizing drug internalization, as well as enhancing the anti-inflammatory and anticancer efficacy of TQ. Additionally, TQ-NPs (thymoquinone nanoparticles) as a therapeutic payload modulated autophagy as well as enhanced the potential of other drugs when given in combination. Moreover, nanoformulations improved pharmacokinetics, drug deposition, using EPR (enhanced permeability and retention) and receptor-mediated delivery, and enhanced anti-inflammatory and anticancer properties. TQ's potential to reduce metal toxicity, its clinical trials and patents have also been discussed.

Thymoquinone Is a Multitarget Single Epidrug That Inhibits the UHRF1 Protein Complex

Silencing of tumor suppressor genes (TSGs) through epigenetic mechanisms, mainly via abnormal promoter DNA methylation, is considered a main mechanism of tumorigenesis. The abnormal DNA methylation profiles are transmitted from the cancer mother cell to the daughter cells through the involvement of a macromolecular complex in which the ubiquitin-like containing plant homeodomain (PHD), and an interesting new gene (RING) finger domains 1 (UHRF1), play the role of conductor. Indeed, UHRF1 interacts with epigenetic writers, such as DNA methyltransferase 1 (DNMT1), histone methyltransferase G9a, erasers like histone deacetylase 1 (HDAC1), and functions as a hub protein. Thus, targeting UHRF1 and/or its partners is a promising strategy for epigenetic cancer therapy. The natural compound thymoquinone (TQ) exhibits anticancer activities by targeting several cellular signaling pathways, including those involving UHRF1. In this review, we highlight TQ as a potential multitarget single epidrug that functions by targeting the UHRF1/DNMT1/HDAC1/G9a complex. We also speculate on the possibility that TQ might specifically target UHRF1, with subsequent regulatory effects on other partners.

Therapeutic perspective of thymoquinone: A mechanistic treatise

The higher utilization of fruits and vegetables is well known to cure human maladies due to the presence of bioactive components. Among these compounds, thymoquinone, a monoterpene and significant constituent in the essential oil of Nigella sativa L., has attained attention by the researchers due to their pharmacologies perspectives such as prevention from cancer, antidiabetic and antiobesity, prevention from oxidative stress and cardioprotective disorder. Thymoquinone has been found to work as anticancer agent against different human and animal cancer stages including propagation, migration, and invasion. Thymoquinone as phytochemical also downregulated the Rac1 expression, mediated the miR-34a upregulation, and increased the levels of miR-34a through p53, as well as also regulated the pro- and antiapoptotic genes and decreased the phosphorylation of NF-κB and IKKα/β. In addition, thymoquinone also lowered the metastasis and ERK1/2 and PI3K activities. The present review article has been piled by adapting narrative review method and highlights the diverse aspects of thymoquinone such as hepatoprotective, anti-inflammatory, and antiaging through various pathways, and further utilization of this compound in diet has been proven effective against different types of cancers.

Thymoquinone Inhibits Proliferation and Migration of MDA-MB-231 Triple Negative Breast Cancer Cells by Suppressing Autophagy, Beclin-1 and LC3

BACKGROUND

Triple Negative Breast Cancer (TNBC) is an aggressive and highly heterogeneous subtype of breast cancer associated with poor prognosis. A better understanding of the biology of this complex cancer is needed to develop novel therapeutic strategies for the improvement of patient survival. We have previously demonstrated that Thymoquinone (TQ), the major phenolic compound found in Nigella sativa, induces anti-proliferative and anti-metastatic effects and inhibits in vivo tumor growth in orthotopic TNBC models in mice. Also, we have previously shown that Beclin-1 and LC3 autophagy genes contributes to TNBC cell proliferation, migration and invasion, suggesting that Beclin-1 and LC3 genes provide proto-oncogenic effects in TNBC. However, the role of Beclin-1 and LC3 in mediating TQ-induced anti-tumor effects in TNBC is not known.

OBJECTIVE

To investigate the effects of TQ on the major autophagy mediators, Beclin-1 and LC3 expression, as well as autophagic activity in TNBC cells.

METHODS

Cell proliferation, colony formation, migration and autophagy activity were evaluated using MTS cell viability, colony formation assay, wound healing and acridine orange staining assays, respectively. Western blotting and RT-PCR assays were used to investigate LC3 and Beclin-1 protein and gene expressions, respectively, in MDA-MB-231 TNBC cells in response to TQ treatments.

RESULTS

TQ treatment significantly inhibited cell proliferation, colony formation, migration and autophagic activity of MDA-MB-231 cells and suppressed LC3 and Beclin-1 expressions. Furthermore, TQ treatment led to the inhibition of Integrin-β1, VEGF, MMP-2 and MMP-9 in TNBC cells.

CONCLUSION

TQ inhibits autophagic activity and expression of Beclin-1 and LC3 in TNBC cells and suppresses pathways related to cell migration/invasion and angiogenesis, including Integrin-β1, VEGF, MMP-2 and MMP- 9, suggesting that TQ may be used to control autophagic activity and oncogenic signaling in TNBC.

Thymoquinone: A Tie-Breaker in SARS-CoV2-Infected Cancer Patients?

Since the beginning of the SARS-CoV-2(severe acute respiratory syndrome-coronavirus-2) pandemic, arace to develop a vaccine has been initiated, considering the massive and rather significant economic and healthcare hits that this virus has caused. The pathophysiology occurring following COVID-19(coronavirus disease-2019) infection has givenhints regarding the supportive and symptomatic treatments to establish for patients, as no specific anti-SARS-CoV-2 is available yet. Patient symptoms vary greatly and range from mild symptoms to severe fatal complications. Supportive treatments include antipyretics, antiviral therapies, different combinations of broad-spectrum antibiotics, hydroxychloroquine and plasma transfusion. Unfortunately, cancer patients are at higher risk of viral infection and more likely to develop serious complications due to their immunocompromised state, the fact that they are already administering multiple medications, as well as combined comorbidity compared to the general population. It may seem impossible to find a drug that possesses both potent antiviral and anticancer effects specifically against COVID-19 infection and its complications and the existing malignancy, respectively. Thymoquinone (TQ) is the most pharmacologically active ingredient in Nigella sativa seeds (black seeds); it is reported to have anticancer, anti-inflammatory and antioxidant effects in various settings. In this review, we will discuss the multiple effects of TQ specifically against COVID-19, its beneficial effects against COVID-19 pathophysiology and multiple-organ complications, its use as an adjuvant for supportive COVID-19 therapy and cancer therapy, and finally, its anticancer effects.

Computational and Experimental Studies Reveal That Thymoquinone Blocks the Entry of Coronaviruses Into In Vitro Cells

INTRODUCTION

Since December 2019, severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has caused the coronavirus disease 2019 (COVID-19) pandemic in China and worldwide. New drugs for the treatment of COVID-19 are in urgent need. Considering the long development time for new drugs, the identification of promising inhibitors from FDA-approved drugs is an imperative and valuable strategy. Recent studies have shown that the S1 and S2 subunits of the spike protein of SARS-CoV-2 utilize human angiotensin-converting enzyme 2 (hACE2) as the receptor to infect human cells.

METHODS

We combined molecular docking and surface plasmon resonance (SPR) to identify potential inhibitors for ACE2 from available commercial medicines. We also designed coronavirus pseudoparticles that contain the spike protein assembled onto green fluorescent protein or luciferase reporter gene-carrying vesicular stomatitis virus core particles.

RESULTS

We found that thymoquinone, a phytochemical compound obtained from the plant Nigella sativa, is a potential drug candidate. SPR analysis confirmed the binding of thymoquinone to ACE2. We found that thymoquinone can inhibit SARS-CoV-2, SARS-CoV, and NL63 pseudoparticles infecting HEK293-ACE2 cells, with half-maximal inhibitory concentrations of 4.999, 7.598, and 6.019 μM, respectively. The SARS-CoV-2 pseudoparticle inhibition had half-maximal cytotoxic concentration of 35.100 μM and selection index = 7.020.

CONCLUSION

Thymoquinone is a potential broad-spectrum inhibitor for the treatment of coronavirus infections.

lncRNA CASC19 Contributes to Radioresistance of Nasopharyngeal Carcinoma by Promoting Autophagy via AMPK-mTOR Pathway

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.

The Role of Autophagy in Gastric Cancer Chemoresistance: Friend or Foe?

Gastric cancer is the third most common cause of cancer-related death worldwide. Drug resistance is the main inevitable and vital factor leading to a low 5-year survival rate for patients with gastric cancer. Autophagy, as a highly conserved homeostatic pathway, is mainly regulated by different proteins and non-coding RNAs (ncRNAs) and plays dual roles in drug resistance of gastric cancer. Thus, targeting key regulatory nodes in the process of autophagy by small molecule inhibitors or activators has become one of the most promising strategies for the treatment of gastric cancer in recent years. In this review, we provide a systematic summary focusing on the relationship between autophagy and chemotherapy resistance in gastric cancer. We comprehensively discuss the roles and molecular mechanisms of multiple proteins and the emerging ncRNAs including miRNAs and lncRNAs in the regulation of autophagy pathways and gastric cancer chemoresistance. We also summarize the regulatory effects of autophagy inhibitor and activators on gastric cancer chemoresistance. Understanding the vital roles of autophagy in gastric cancer chemoresistance will provide novel opportunities to develop promising therapeutic strategies for gastric cancer.

Aurora-B knockdown inhibits osteosarcoma metastasis by inducing autophagy via the mTOR/ULK1 pathway

Background

Autophagy plays an essential role in metastasis of malignancies. Although our studies showed that Aurora-B facilitate pulmonary metastasis in OS, the mechanism of Aurora-B kinase on autophagy and metastasis in OS has not been explored.

Methods

Clinical-pathological parameters and follow-up information was collected in OS patients. Immunohistochemical staining was performed to detect Aurora-B and LC3 protein in OS tissues. Short hairpin RNA transfection was used to silence Aurora-B in OS cells. Real-time quantitative PCR (RT-qPCR) was performed to detect Aurora-B mRNA expression in OS cells. Aurora-B and autophagy related protein were measured by Western blot. Transmission electron microscopy and laser scanning confocal microscopy were performed to observe the formation of autophagosomes and autolysosomes. Migratory and invasive ability of OS cells were measured by Wound healing and transwell assays. Orthotopic xenograft model was used to evaluate the effect of autophagy mediated by Aurora-B inhibition on pulmonary metastasis of OS.

Results

The elevated expression of Aurora-B protein in OS tissues negatively associated with the overall survival of OS patients. Further investigation has found that Aurora-B expression was negatively correlative with autophagy related protein LC3 in OS patient tissues. Knockdown Aurora-B stimulates autophagy and inhibits migratory and invasive ability of OS cells. Mechanistically, Aurora-B knockdown suppressed the mTOR/ULK1 signaling pathway and reactivation of the mTOR/ULK1 pathway decreased autophagy level. Furthermore, the inhibition effect of silencing Aurora-B on migration and invasion of OS was reversed by chloroquine and mTOR activator in vitro and vivo.

Conclusions

Our results suggest that silencing of Aurora-B stimulate autophagy via decreasing mTOR/ULK1 and result in inhibiting OS metastasis. Targeted Aurora-B/mTOR/ULK1 pathway may be a promising treatment strategy for OS patients.

Sublethal irradiation promotes the metastatic potential of hepatocellular carcinoma cells

Radiotherapy (RT) represents one of the major treatment methods for cancers. However, many studies have observed that in descendant surviving tumor cells, sublethal irradiation can promote metastatic ability, which is closely related to the tumor microenvironment. We therefore investigated the functions and mechanisms of sublethal irradiated liver nonparenchymal cells (NPCs) in hepatocellular carcinoma (HCC). In this study, primary rat NPCs and McA‐RH7777 hepatoma cells were irradiated with 6 Gy X‐ray. Conditioned media (CM) from nonirradiated (SnonR), irradiated (SR), or irradiated plus radiosensitizer celecoxib‐treated (S[R + D]) NPCs were collected and added to sublethal irradiated McA‐RH7777 cells. We showed that CM from sublethal irradiated NPCs significantly promoted the migration and invasion ability of sublethal irradiated McA‐RH7777 cells, which was reversed by celecoxib. The differentially expressed genes in differently treated McA‐RH7777 cells were enriched mostly in the AMP‐activated protein kinase/mammalian target of rapamycin (AMPK/mTOR) signaling pathway. SR increased the migration and invasion ability of HCC cells by inhibiting AMPK/mTOR signaling, which was enhanced by the AMPK inhibitor compound C and blocked by the AMPK activator GSK‐621. Analyses of HCC tissues after neoadjuvant radiotherapy confirmed the effects of radiation on the AMPK/mTOR pathway. Cytokine antibody arrays and further functional investigations showed that matrix metalloproteinase‐8 (MMP‐8) partly mediates the promotion effects of SR on the migration and invasion ability of HCC cells by regulating AMPK/mTOR signaling. In summary, our data indicate that MMP‐8 secreted by irradiated NPCs enhanced the migration and invasion of HCC by regulating AMPK/mTOR signaling, revealing a novel mechanism mediating sublethal irradiation–induced HCC metastasis at the level of the tumor microenvironment.

A comprehensive insight into potential roles of Nigella sativa on diseases by targeting AMP-activated protein kinase: a review

OBJECTIVES

Nigella sativa (NS) is a known medicinal herb with numerous therapeutic effects such as antidiabetic, anti-proliferative, anti-inflammatory, and anti-cancer activities. It has been indicated that NS can regulate cellular metabolism by adjusting transduction signaling pathways. Adenosine monophosphate-activated protein kinase (AMPK) is one of the main physiological processes, such as energy hemostasis, cellular metabolism, and autophagy regulators. Herb-derived medicines have always been considered as one of the main AMPK activators, and surprisingly recent data has demonstrated that it can be a target for NS and its derivatives.

EVIDENCE ACQUISITION

The literature search was conducted in PubMed, SCOPUS, Embase, ProQuest, and Google Scholar electronic resources. Published articles up to September 2020 were considered, and those of which investigated Nigella sativa effects on the AMPK pathway after meeting the inclusion criteria were included.

RESULTS

The search was performed on several online databases such as PubMed, Scopus, Embase, ProQuest, and Google Scholar from inception until January 2020. Among the initial search, 245 studies were found. After removing duplicated data and meeting the inclusion criteria, only 14 studies were selected. They included the effects of NS and its bioactive compounds as anti-hyperglycemic (n = 5), on liver function (n = 4), cancers (n = 3), and on Neuroinflammation and Atherosclerosis (n = 2). Most of the included studies are animals or in-vitro investigations.

CONCLUSION

In this review, we discuss the latest findings on the molecular mechanism of NS effecting the AMPK signaling pathway. We also focus on the therapeutic effects of NS, including the prevention and treatment of metabolic and pro-inflammatory disease by targeting the AMPK pathway.

Circ-EEF2 facilitated autophagy via interaction with mir-6881-3p and ANXA2 in EOC

Circular RNAs, a special class of non-coding RNA with closed circular structure, have been increasingly proven to be involved in the progression of various tumors. However, the biological functions of circular RNAs in epithelial ovarian cancer (EOC) tissues remain a mystery. In this study, we detected the function of circEEF2 (has-circ-0048559) in EOC tissues. Firstly, the basic characteristics including closed circular structure and spliced mature sequence length of circEEF2 were confirmed. The location and expression in EOC tissues was detected by fluorescence in situ hybridization (FISH). The regulatory effect of circEEF2 on autophagy, proliferation, and invasion were investigated in SKOV3 and A2780 cells. The relationship between circEEF2 and mir-6881-3p was confirmed using dual-luciferase reporter gene assay. The binding of circEEF2 with ANXA2 was confirmed using RNA-pulldown assay and MALDI-TOF-MS. We found that the expression level of circEEF2 was higher in EOC tissue than in normal tissue. CircEEF2 promoted autophagy, proliferation, and invasion. CircEEF2-regulated EOC proliferation and invasion are closely related to the occurrence of autophagy. Mechanistically, circEEF2 harbor miR-6881-3p to upregulate the latter's targets ATG5 and ATG7. Moreover, circEEF2 could directly bind with ANXA2 to inhibit the expression of p-mTOR. In conclusion, findings of the current study illustrate that circEEF2 promoted autophagy, proliferation, and invasion of EOC by interacting with miR-6881-3p and ANXA2.

Identification of an independent autophagy-gene prognostic index for papillary renal cell carcinoma

Background

Autophagy was a significant catabolic process which played a critical role in the maintenance of cellular homeostasis and viability in a stressed state. The dysregulation of autophagy was correlated with various diseases. The aim of our study was to develop a prognostic signature for papillary renal cell carcinoma (RCC).

Methods

First, 40 differently expressed genes related with autophagy (ARGs) were examined via high-throughput sequencing and large-scale databases. Then, functional enrichment analysis was performed to explore the biological attributes of these ARGs. The Cox proportional hazard regression hinted that four ARGs (P4HB, BIRC5, NGR1 and PRKN) were significantly correlated with overall survival (OS). Thus, we got genes with prognostic value. Finally, a prognostic index (PI) was constructed.

Results

After identifying the 4 ARGs, we profiled our risk signature. Based on the PI we developed, papillary RCC patients were stratified into high-risk and low-risk groups. High-risk patients had significant shorter OS than low-risk patients (P<0.001) and the mortality of high scoring patients was higher than low scoring patients. Additionally, we explored the relationship between the 4 ARGs and clinical parameters and found that the expression of P4HB, BIRC5 and NGR1 was correlated with clinicopathological features.

Conclusions

Our study suggested that the four-gene signature was an independent prognostic factor which could act as a novel indicator for the prognosis of papillary RCC.

VEGF knockdown enhances radiosensitivity of nasopharyngeal carcinoma by inhibiting autophagy through the activation of mTOR pathway

Vascular endothelial growth factor (VEGF) is an important pro-angiogenic factor. VEGF was reported to promote the occurrence of autophagy, which enhanced the radioresistance of tumors. The purpose of this study was to investigate the influence of VEGF silencing on the radiosensitivity of nasopharyngeal carcinoma (NPC) cells and the underlying mechanisms. The radiosensitivity of NPC cells after VEGF silencing was detected by cell counting kit 8 (CCK-8) and clonogenic assay, while cell cycle and apoptosis were detected by flow cytometry. The processes of DNA damage, repair and autophagy were examined by immunofluorescence and western blotting. The interaction between VEGF and mTOR was confirmed by western blotting and co-immunoprecipitation studies. The effect of VEGF on radiosensitivity of NPC cells was investigated in vivo using a xenograft model. Furthermore, immunohistochemistry and TUNEL assays were used to verify the relationship between autophagy and radiosensitivity in NPC after VEGF depletion. Downregulation of VEGF significantly inhibited cell proliferation and induced apoptosis of NPC cells after radiotherapy in vitro and in vivo. In addition, VEGF knockdown not only decreased autophagy level, but also delayed the DNA damage repair in NPC cells after irradiation. Mechanistically, silencing VEGF suppressed autophagy through activation of the mTOR pathway. VEGF depletion increased radiosensitivity of NPC cells by suppressing autophagy via activation of the mTOR pathway.

Chemopreventive and Anticancer Effects of Thymoquinone: Cellular and Molecular Targets

Thymoquinone (TQ) is a bioactive component derived from the seeds of Nigella sativa that are commonly as black cumin. Evidences indicate that the medicinal properties of TQ have been recognized for more than 2000 years. TQ has been shown to possess potent chemopreventive properties that include anti-inflammatory and anti-neoplastic activities. Recent studies have unraveled the multiple mechanisms through which TQ exerts its chemopreventive and anticancer activity in different cancer cells in a contextual manner. The present review aims to provide a brief compendium on the molecular mechanisms through which TQ inhibits signaling pathways underlying cancer genesis, progression, and metastasis.

Thymoquinone, an Active Compound of Nigella sativa: Role in Prevention and Treatment of Cancer

Background:

Cancer is the leading cause of death worldwide and the current mode of cancer treatment causes side effects on normal cells and are still the key challenges in its’ treatment. However, natural products or active compounds of medicinal plants have shown to be safe, affordable, and effective in diseases cure.

Methods:

In this context, scientific studies evidence the health-promoting effects of natural products, which work through its anti-oxidant, anti-inflammatory, and anti-cancer activity. Thymoquinone (TM), a predominant active compound of Nigella sativa, has confirmed anti-neoplastic activity through its ability to regulate various genetic pathways. In addition, thymoquinone has established anti-cancerous effects through killing of various cancerous cells,and inhibiting the initiation, migration, invasion, and progression of the cancer. The anti-cancer effects of TM are chiefly mediated via regulating various cell signaling pathways such as VEGF, bcl2/bax ratio, p53, NF-kB, and oncogenes.

Results:

The anti-cancer drugs have limitations in efficacy and also causes adverse side effects on normal cells. The combination of anti-cancer drugs and thymoquinone improves the efficacy of drugs which is evident by decrease resistance to drugs and regulation of various cell signaling pathways. Moreover, combination of anti-cancer drugs as well as thymoquinone shows synergistic effect on killing of cancer cells and cells viability. Thus, TM, in combination with anti-cancer drugs, can be a good strategy in the management of various types of cancer.

Conclusion:

In this review article, we deliver an outline of thymoquinone role in cancer inhibition and prevention of cancer-based on in vivo and in vitro studies. Further studies on thymoquinone based on clinical trials are highly required to explore the benefits of thymoquinone in cancer management.