Oluwaseun Adebayo Bamodu

Aberrant KDM5B expression promotes aggressive breast cancer through MALAT1 overexpression and downregulation of hsa-miR-448

AbstractBackgroundTriple negative breast cancers (TNBC) possess cell dedifferentiation characteristics, carry out activities connate to those of cancer stem cells (CSCs) and are associated with increased metastasis, as well as, poor clinical prognosis. The regulatory mechanism of this highly malignant phenotype is still poorly characterized. Accruing evidence support the role of non-coding RNAs (ncRNAs) as potent regulators of CSC and metastatic gene expression, with their dysregulation implicated in tumorigenesis and disease progression.MethodsIn this study, we investigated TNBC metastasis, metastasis-associated genes and potential inhibitory mechanisms using bioinformatics, tissue microarray analyses, immunoblotting, polymerase chain reaction, loss and gain of gene function assays and comparative analyses of data obtained.ResultsCompared with other breast cancer types, the highly metastatic MDA-MB-231 cells concurrently exhibited increased expression levels of Lysine-specific demethylase 5B protein (KDM5B) and long non-coding RNA (lncRNA), MALAT1, suggesting their functional association. KDM5B-silencing in the TNBC cells correlated with the upregulation of hsa-miR-448 and led to suppression of MALAT1 expression with decreased migration, invasion and clonogenic capacity in vitro, as well as, poor survival in vivo. This projects MALAT1 as a mediator of KDM5B oncogenic potential and highlights the critical role of this microRNA, lncRNA and histone demethylase in cancer cell motility and metastatic colonization. Increased expression of KDM5B correlating with disease progression and poor clinical outcome in breast cancer was reversed by hsa-miR-448.ConclusionsOur findings demonstrate the critical role of KDM5B and its negative regulator hsa-miR-448 in TNBC metastasis and progression. Hsa-miR-448 disrupting KDM5B-MALAT1 signalling axis and associated activities in TNBC cells, projects it as a putative therapeutic factor for selective eradication of TNBC cells. Graphical abstractKDM5B, MALAT1 and hsa-miR-448 are active looped components of the epigenetic poculo mortis in aggressive breast cancer.

Ovatodiolide sensitizes aggressive breast cancer cells to doxorubicin, eliminates their cancer stem cell-like phenotype, and reduces doxorubicin-associated toxicity

Triple-negative breast cancer (TNBC) is chemotherapy-refractory and associated with poor clinical prognosis. Doxorubicin (Doxo), a class I anthracycline and first-line anticancer agent, effective against a wide spectrum of neoplasms including breast carcinoma, is associated with several cumulative dose-dependent adverse effects, including cardiomyopathy, typhilitis, and acute myelotoxicity. This study evaluated the usability of Ovatodiolide (Ova) in sensitizing TNBC cells to Doxo cytotoxicity, so as to reduce Doxo effective dose and consequently its adverse effects. TNBC cell lines MDA-MB-231 and HS578T were used. Pre-treatment of the TNBC cells with 10 µM Ova 24 h before Doxo administration increased the Doxo anticancer effect (IC50 1.4 µM) compared to simultaneous treatment with Doxo ( IC50 1.8 µM), or Doxo alone (IC50 9.2 µM). Intracellular accumulation of Doxo was lowest in Ova pre-treated cells at all Doxo concentrations, when compared with Doxo or simultaneously treated cells. In comparison to the Doxo-only group, cell cycle analysis of MDA-MB-231 cells treated concurrently with 2.5 µM Ova and 1.25 µM Doxo showed increased percentage of cells arrested at G0/G1; however, pre-treatment with the same concentration of Ova 24 h before Doxo showed greater tumor growth inhibition, with a 2.4-fold increased percentage of cells in G0/G1 arrest, greater Doxo-induced apoptosis, and significantly reduced intracellular Doxo accumulation. Additionally, Ova-sensitized TNBC cells also lost their cancer stem cell-like phenotype evidenced by significant dissolution, necrosis of formed mammospheres. Taken together, these findings indicate that Ova sensitizes TNBC cells to Doxo and potentiates doxorubicin-induced elimination of the TNBC cancer stem cell-like phenotype.

Methoxyphenyl chalcone sensitizes aggressive epithelial cancer to cisplatin through apoptosis induction and cancer stem cell eradication

Current standard chemotherapy for late stage ovarian cancer is found unsuccessful due to relapse after completing the regimens. After completing platinum-based chemotherapy, 70% of patients develop relapse and resistance. Recent evidence proves ovarian cancer stem cells as the source of resistance. Therefore, treatment strategy to target both cancer stem cells and normal stem cells is essential. In this study, we developed a novel chalcone derivative as novel drug candidate for ovarian cancer treatment. We found that methoxyphenyl chalcone was effective to eliminate ovarian cancer cells when given either as monotherapy or in combination with cisplatin. We found that cell viability of ovarian cancer cells was decreased through apoptosis induction. Dephosphorylation of Bcl2-associated agonist of cell death protein was increased after methoxyphenyl chalcone treatment that led to activation of caspases. Interestingly, this drug also worked as a G2/M checkpoint modulator with alternative ways of DNA damage signal–evoking potential that might work to increase response after cisplatin treatment. In addition, methoxyphenyl chalcone was able to suppress autophagic flux and stemness regulator in ovarian spheroids that decreased their survival. Therefore, combination of methoxyphenyl chalcone and cisplatin showed synergistic effects. Taken together, we believe that our novel compound is a promising novel therapeutic agent for effective clinical treatment of ovarian cancer.

4-Acetylantroquinonol B suppresses autophagic flux and improves cisplatin sensitivity in highly aggressive epithelial cancer through the PI3K/Akt/mTOR/p70S6K signaling pathway

ABSTRACT Targeting residual self‐renewing, chemoresistant cancerous cells may represent the key to overcoming therapy resistance. The entry of these quiescent cells into an activated state is associated with high metabolic demand and autophagic flux. Therefore, modulating the autophagy pathway in aggressive carcinomas may be beneficial as a therapeutic modality. In this study, we evaluated the anti‐tumor activities of 4‐acetylantroquinonol B (4‐AAQB) in chemoresistant ovarian cancer cells, particularly its ability to modulate autophagy through autophagy‐related genes (Atg). Atg‐5 was overexpressed in invasive ovarian cancer cell lines and tissue (OR: 5.133; P = 0.027) and depleting Atg‐5 in ES‐2 cell lines significantly induced apoptosis. 4‐AAQB effectively suppressed viability of various subtypes of ovarian cancer. Cells with higher cisplatin‐resistance were more responsive to 4‐AAQB. For the first time, we demonstrate that 4‐AAQB significantly suppress Atg‐5 and Atg‐7 expression with decreased autophagic flux in ovarian cancer cells via inhibition of the PI3K/Akt/mTOR/p70S6K signaling pathway. Similar to Atg‐5 silencing, 4‐AAQB‐induced autophagy inhibition significantly enhanced cell death in vitro. These results are comparable to those of hydroxychloroquine (HCQ). In addition, 4‐AAQB/cisplatin synergistically induced apoptosis in ovarian cancer cells. In vivo, 4‐AAQB/cisplatin also significantly induced apoptosis and autophagy in an ES‐2 mouse xenografts model. This is the first report demonstrating the efficacy of 4‐AAQB alone or in combination with cisplatin on the suppression of ovarian cancer via Atg‐5‐dependent autophagy. We believe these findings will be beneficial in the development of a novel anti‐ovarian cancer therapeutic strategy. HIGHLIGHTSAtg‐5 is overexpressed in ovarian cancer and silencing Atg‐5 induces apoptosis.4‐AAQB suppresses autophagy and PI3K/Akt/mTOR pathway.4‐AAQB + cisplatin synergistically suppresses ovarian cancer via autophagy.

Antrodia cinnamomea sensitizes radio-/chemo-therapy of cancer stem-like cells by modulating microRNA expression

ETHNOPHARMACOLOGICAL RELEVANCE The discovery of many tissue-specific cancer stem cells (CSCs) continues to attract scientific attention. These CSCs are considered to be associated with chemo- and radio-resistance, and consequently, failure of conventional anticancer therapies. The recent demonstration of several microRNAs as enhancers of tumorigenicity via modulation of epithelial-mesenchymal transition and cancer stemness, makes them putative novel therapeutic target in oncology. Antrodia cinnamomea is a Chinese traditional medicine with several biological functions including anti-inflammation, antioxidant, and cancer prevention. However, the anti-CSC capability of A. Cinnamomea is not clear yet. AIM OF THE STUDY To investigate the inhibitory effect of A. cinnamomea mycelium and extract on CSCs derived from various human cancer cell lines using our in-house therapeutics and human genome-wide miRNA screening panels. MATERIALS AND METHODS A broad range of human cancer cell lines, including the acute monocytic leukemia (THP-1), glioblastoma multiforme (GBM 8401), lung carcinoma (A549), breast adenocarcinoma (MDA-MB-231), hepatoblastoma (HepG2), colorectal adenocarcinoma (SW620), and foreskin fibroblast (HS68), were exposed to A. cinnamomea in this study. CD133+ CSCs generated from the cell lines were characterized and isolated by flow cytometry, effect of chemo- and radiotherapy was assessed using the MTT assay, while the RT-PCR and human genome wide qRT-PCR determined the differential gene expression patterns. A comparative analysis of the anticancer effect of A. cinnamomea and Cisplatin, Taxol, or irradiation was also performed. RESULTS Our results indicated that A. cinnamomea mycelium and its ethyl acetate extracts showed anti-proliferation effects against all types of CSCs, especially the lung, breast, and head and neck squamous cell carcinoma CSCs. Furthermore, CSCs treatment with A. cinnamomea combined with irradiation or chemotherapeutics demonstrated significant anti-cancer effect. We also established an association between the CSC-inhibitory effect of A. cinnamomea and significant downregulation of several microRNAs and cancer stemness expression levels in brain and breast CSCs. More importantly, higher CD133 expression is associated with poor prognosis in glioblastoma and breast cancer patients. CONCLUSION Herein, we demonstrate the putative role of A. cinnamomea as an effective ethnopharmacologic therapeutic agent for cancer treatment.

Ovatodiolide suppresses yes-associated protein 1-modulated cancer stem cell phenotypes in highly malignant hepatocellular carcinoma and sensitizes cancer cells to chemotherapy in vitro

The cancer stem cells (CSCs) theory recently became a focus of heightened attention in cancer biology, with the proposition that CSCs may constitute an important therapeutic target for effective anticancer therapy, because of their demonstrated role in tumor initiation, chemo-, and radio-resistance. Liver CSCs are a small subpopulation of poorly- or undifferentiated liver tumor cells, implicated in tumorigenesis, metastasis, resistance to therapy and disease relapse, enriched with and associated with the functional markers corresponding to the CSCs-enriched side population (SP), high aldehyde dehydrogenase (ALDH) activity, and enhanced formation of in vitro liver CSCs models, referred to herein as hepatospheres. In this study, we found YAP1 was significantly expressed in the SP cells, as well as in generated hepatospheres compared to non-SP or parental HCC cells, at transcript and/or protein levels. In addition, downregulation of YAP1 expression levels by small molecule inhibitor and siRNA transfection, in the HCC cell lines, PLC/PRF/5 and Mahlavu, were associated with marked loss of ability to form hepatospheres and increased sensitivity to sorafenib. Consistent with the above, we demonstrated that YAP1 expression positively correlated with that of Sox2, Oct4, c-Myc and GRP78, markers of stemness and drug resistance. This is suggestive of YAP1s role as a modulator of cancer stemness, ER stress and chemoresistance. For the first time, we demonstrate that Ovatodiolide significantly attenuates YAP1 expression and subsequently suppressed YAP1-modulated CSCs phenotypes and associated disease progression, consistent with our previous finding in breast cancer. Taken together, our findings suggest that YAP1, highly expressed in malignant liver tumours, contributes to hepatocellular CSCs phenotype and is a molecular target of interest for CSCs targeted therapy in liver cancer patients.

Ovatodiolide suppresses nasopharyngeal cancer by targeting stem cell-like population, inducing apoptosis, inhibiting EMT and dysregulating JAK/STAT signaling pathway

BACKGROUND Treatment for metastatic nasopharyngeal carcinoma (NPC) is challenging. Till now, a truly effective chemotherapy regimen for NPC has not yet been identified. These clinical observations prompted us to investigate a potential drug as alternative option for treating. PURPOSE This study evaluated the inhibitory effects of Ovatodiolide (Ova), on tumorigenic and cancer stem cell characteristics of NPC cells. METHODS Two NPC cell lines (NPC-BM1 and NPC-BM2) were used to examine the anticancer effects of Ova and the molecular mechanism underlying these activities by using sulforhodamine B cytotoxicity assay, western blot, immunofluorescence, migration, colony and tumorsphere formation assays. RESULTS Ova significantly inhibited the viability of BM1 and BM2 cells, downregulated Bcl-xL and Puma, and upregulated Bax/Bad expression levels. Ova dose-dependent suppressed migratory/invasive potential of NPC cells, and reduced ability to form colonies. Ova-induced apoptosis correlated with increased Bax/Bcl-xL ratio while NPC motility and colony formation inhibition were associated with reduced expression of p-FAK, p-PXN, F-actin, and Slug proteins and increased E-cadherin. Furthermore, ova inhibited NPC tumorsphere formation, associated with decreased SOX2, OCT4 and JAK-STAT signaling pathway. Ova also attenuated NPC stem cell tumorigenicity, inhibited tumor growth, and enhanced the sensitivity of NPC cells to cisplatin treatment, in vivo. CONCLUSIONS Our results demonstrated the anticancer efficacy of Ova in NPC and its potential as a putative inhibitor of JAK2 and STAT3, which are essential in tumorigenesis of NPC. Further development of Ova is encouraged.

Investigation of Ovatodiolide, a Macrocyclic Diterpenoid, as a potential inhibitor of Oral Cancer Stem-Like Cells Properties via the Inhibition of the JAK2/STAT3/JARID1B Signal Circuit

BACKGROUND The cancer stem cells (CSCs) have been shown to play key roles in the oral cancer initiation, distant metastasis, the development of chemoresistance and recurrence after treatment. Therefore, the inhibition of oral CSCs has been the target for therapeutic development. PURPOSE In this study, we investigated the anti-CSCs potential of Ovatodiolide (Ova), a diterpenoid isolate of Anisomeles indica, in vitro and in vivo. METHODS Oral CSCs were treated with Ova, and the expression of pluripotency factors Oct4, Sox-2, and Nanog were evaluated by western blot. Effect of Ova on self-renewal capacity and clonogenicity were assessed with the sphere formation and clonogenic assay in CSCs model derived from oral cancer cell. The effect of Ova was also investigated in a mouse xenograft model obtained by injecting nude mice with oral CSCs cells. RESULTS We demonstrated that Ova significantly and dose-dependently suppressed oral cancer cell viability and colony formation; Ova markedly inhibited the ALDH1 activities and reduced the CD44high/ALDHrich cell sub-population. Additionally, Ova suppressed orosphere formation by down-regulating CD133, Klf4, Oct4A, Nanog and JARID1B expression. Furthermore, Ova-mediated anti-cancer effects were associated with the dose-dependent reduction in the expression levels of STAT3, p-STAT3, pJAK2, pAKT and pERK1/2 protein. Moreover, Ova synergistically enhanced the anticancer effect of cisplatin against the SAS, FaDu, HSC-3 and TW2.6 orospheres. Ova significantly attenuated the tumor-initiating potential of orosphere in mouse xegnograft model. CONCLUSION These results demonstrate that Ova effectively suppressed oral tumorigenesis and stemness properties via JAK2/STAT3 signaling. Ova may be considered for future clinical usage.

Activation of the monocytic α7 nicotinic acetylcholine receptor modulates oxidative stress and inflammation-associated development of coronary artery spasm via a p38 MAP-kinase signaling-dependent pathway

Objective: Smoking and high‐sensitivity C‐reactive protein (hs‐CRP) are risk factors for coronary artery spasm (CAS), which is characterized by the increased interleukin‐6 (IL‐6) level and monocyte counts; however, limited data are available regarding the role of cigarette‐embedded nicotine in the modulation of monocytic inflammatory activity in CAS. Approach: We investigated and elucidated the putative roles and associations of nicotine, monocytic IL‐6, &agr;7 nicotinic acetylcholine receptor (&agr;7‐nAChR), and CRP in CAS development. Results: We demonstrated that a significantly increased &agr;7‐nAChR (p=0.001) and IL‐6 (p=0.0036) messenger RNA (mRNA) expression in the serum of patients with CAS. Serum hs‐CRP levels exhibited a strong positive correlation with the monocytic mRNA expression of &agr;7‐nAChR (r=0.71, p<0.001) and IL‐6 (r=0.49, p=0.006). The &agr;7‐nAChR and IL‐6 expression levels of the CAS group were also positively correlated (r=0.63, p<0.001). Compared with the untreated controls, THP‐1 cells and patient‐derived monocytes treated with different concentrations of CRP displayed significantly increased expression levels of &agr;7‐nAChR mRNA and protein (p=0.0054), in a dose‐dependent manner. We also demonstrated that compared with the IL‐6 expression elicited by CRP alone (p=0.0489), the CRP‐induced rise in monocytic IL‐6 mRNA and protein expression in the presence of nicotine (p=0.0002), is mediated by &agr;7‐nAChR activation and the deregulation of the human p38 mitogen‐activated protein kinases (MAPK) signaling pathway. Conclusions: Our data demonstrate that the elevated monocytic IL‐6 and &agr;7‐nAChR mRNA and protein expression levels are associated with the interaction between nicotine and CRP positively modulates CAS development. Our study suggests the potential role of &agr;7‐nAChR mRNA and/or protein expression as a diagnostic biomarker for CAS. HIGHLIGHTSCurrent smoking status and hs‐CRP tertile are independently associated with CAS.Monocytic &agr;7‐nAChRs, hs‐CRP and IL‐ 6 are highly expressed in serum of CAS patients.The expression of &agr;7‐nAChRs in the monocytes of CAS patients is augmented in an inflammatory milieu.Nicotine‐enhanced inflammation in CAS patients is mediated by &agr;7‐nAChR.

Upregulated SCUBE2 expression in breast cancer stem cells enhances triple negative breast cancer aggression through modulation of notch signaling and epithelial-to-mesenchymal transition

Background: Metastatic and/or recurrent breast carcinomas are leading causes of cancer‐related death worldwide. Breast cancer stem cells (BCSCs) have been implicated in cancer metastases and progression, thus, the need for the discovery and development of effective BCSCs‐specific therapies against metastatic and triple negative breast cancer (TNBC). The expression of SCUBE2, originally identified in vascular endothelia, then in several non‐endothelial cell types, is downregulated in invasive breast carcinomas. However, the role of SCUBE2 in BCSCs remains unknown. This present study investigated the probable involvements of SCUBE2 in BCSCs and TNBC metastasis. Methods: The mRNA expression of SCUBE2, stemness and EMT markers in MDA‐MB‐231 and Hs578T tumorspheres or adherent cells were evaluated by qRT‐PCR and microarray analyses. Using gene overexpression, in vitro migration and invasion assays, as well as in vivo bioluminescence imaging, we evaluated the role of SCUBE2 in MDA‐MB‐231 or Hs578T BCSCs. Western blot and cytotoxicity assays helped identify and validate SCUBE2 molecular target(s) and inhibitor(s). Results: Concurrently increased SCUBE2 expression and cell motility were observed in TNBC tumorspheres compared to the parental adherent cells. SCUBE2 overexpression augmented BCSCs motility in vitro, and enhanced TNBC metastasis in vivo. While SCUBE2 overexpression activated Notch signaling its downregulation suppressed Notch signal effectors NICD, Jagged 1, HEY1, and HES1. Conclusions: We demonstrate that SCUBE2 expression is upregulated in BCSCs, promote EMT and enhance TNBC metastasis by activating Notch signaling. This reveals a potential druggable molecular target and an effective therapeutic strategy against metastatic and aggressive TNBC. Graphical abstract Figure. No Caption available. HighlightsSCUBE2 overexpression enhances the cancer stem cell‐like and metastatic phenotypes.SCUBE2 modulation of the Notch signaling pathway.SCUBE2 high/ALDH+ TNBC cells exhibit enhanced tumorigenicity in vivo.