Exploring Anticancer Properties of Medicinal Plants against Breast Cancer by Downregulating Human Epidermal Growth Factor Receptor 2

Plants have a history of being employed in managing breast cancer. However, no scientific evidence supports the idea that these plants can effectively reduce the level of HER2 expression. In this study, extracts from 10 medicinal plants were evaluated for their anticancer properties against HER2-positive breast cancer cells through various methods, including the SRB assay, comet assay, annexin V-FITC dual staining, and immunoblotting. All extracts exerted antiproliferative activity against HER2-positive breast cancer cells. Furthermore, Terminalia chebula (T. chebula), Berberis aristata (B. aristata), and Mucuna pruriens (M. pruriens) reduced HER2 expression in tested cell lines. In addition, an increased Bax/Bcl-2 ratio was observed after the treatment. A comparative proteomics study showed modulation in the proteome profile of breast cancer cells after treatment with T. chebula, B. aristata, Punica granatum, M. pruriens, and Acorus calamus. Metabolic profiling of lead plants revealed the existence of multiple anticancer compounds. Our study demonstrates the considerable potential of the mentioned plants as innovative therapies for HER2-positive breast cancer.

Talazoparib enhances the quinacrine-mediated apoptosis in patient-derived oral mucosa CSCs by inhibiting BER pathway through the modulation of GCN5 and P300

The presence of cancer stem cells (CSCs) in the tumor microenvironment (TME) is majorly responsible for the development and recurrence of cancer. Earlier reports suggested that upon DNA damage, poly-(ADP-ribose) polymerase-1 (PARP-1) helps in chromatin modulation and DNA repair process, thereby promoting CSC survival. But whether a combination of DNA damaging agents along with PARP inhibitors can modulate chromatin assembly, inhibit DNA repair processes, and subsequently target CSCs is not known. Hence, we have investigated the effect of nontoxic bioactive compound quinacrine (QC) and a potent PARP inhibitor Talazoparib in patient-derived oral mucosa CSCs (OM-CSCs) and in vivo xenograft mice preclinical model systems. Data showed that QC + Talazoparib inhibited the PARP-1-mediated chromatin remodelers' recruitment and deregulated HAT activity of GCN5 (general control nonderepressible-5) and P300 at DNA damage site, thereby preventing the access of repair proteins to the damaged DNA. Additionally, this combination treatment inhibited topoisomerase activity, induced topological stress, and induced apoptosis in OM-CSCs. Similar results were observed in an in vivo xenograft mice model system. Collectively, the data suggested that QC + Talazoparib treatment inhibited BER pathway, induced genomic instability and triggered apoptosis in OM-CSCs through the deregulation of PARP-1-mediated chromatin remodelers (GCN5 and P300) activity. Schematic representation of QC + Talazoparib-induced apoptosis in oral mucosa CSCs. (1) Induction of DNA damage takes place after QC treatment (2) PARP1-mediated PARylation at the site of DNA damage, which recruits multiple chromatin remodelers (3) Acetylation at the histone tails relax the structure of chromatin and recruits the BER pathway proteins at the site of DNA damage. (4) BER pathway activated at the site of DNA damage. (5) CSCs survive after successful repair of DNA damage. (6) Treatment of QC-treated CSCs with PARP inhibitor Talazoparib (7) Inhibition of PARylation results in failure of chromatin remodelers to interact with PARP1. (8) Inhibition of acetylation status leads to chromatin compaction. (9) BER pathway proteins are not recruited at the site of DNA damage, resulting in inhibition of BER pathway and accumulation of unrepaired DNA damage, leading to apoptosis and cell death.

Quinacrine inhibits cMET-mediated metastasis and angiogenesis in breast cancer stem cells

A trans-membrane receptor tyrosine kinase, cMET, belonging to the MET proto-oncogene family, is responsible for cancer metastasis and angiogenesis. But not much is known about the role of cMET in growth and progression of cancer stem cells (CSCs). Earlier studies have shown that Quinacrine (QC), a bioactive agent, has anti-CSCs activity. Here, the role of QC in deregulation of cMET-mediated metastasis and angiogenesis has been systematically evaluated in vitro in highly metastatic breast CSCs (mBCSCs), ex vivo in patient-derived breast cancer stem cells (PDBCSCs) and in vivo in xenograft mice model systems. Cell proliferation, migration, invasion and representative metastasis markers were upregulated in cMET-overexpressed cells and QC exposure inhibited these processes in both mBCSCs and PDBCSCs. Interestingly, metastasis was significantly inhibited by QC in cMET-overexpressed cells but comparatively lesser significant alteration of the process was noted in cMET-silenced cells. Increase in vascularization (in in ovo CAM assay), and cell-cell tube formation (in HUVECs), and enhanced MMP9 and MMP2 enzymatic activities (in gelatin zymography) were noted after cMET overexpression but these processes got reversed after cMET knockdown or QC treatment in cMET-overexpressed cells. QC inhibited angiogenesis significantly in cMET-overexpressed cells, but lesser significant change was observed in cMET-silenced cells. Reduction in tumor volume and decreased expression of metastatic and angiogenic markers were also noted in xenograft mice after QC treatment. Furthermore, QC inhibited cMET activity by dephosphorylation of its tyrosine residues (Y1234 and Y1356) and downregulation of its downstream cascade. Thus, QC inhibited the cMET-mediated metastasis and angiogenesis in in vitro, in ovo, in vivo and ex vivo model systems. Ligand (HGF) binding leads to receptor dimerization and phosphorylation of tyrosine kinase domain of cMET. This activates the cMET signaling cascade. The representative downstream metastasis and angiogenesis-related proteins get upregulated and induce the metastasis and angiogenesis process. But after the QC treatment, cMET get dephosphorylated and inactivated. As a result, the downstream signaling proteins of cMET along with the other representative metastatic and angiogenic factors get downregulated. These lead to inhibition of cMET-mediated metastasis and angiogenesis. (Created with BioRender.com).

Synergetic reinforcing effect of graphene oxide and nanosilver on carboxymethyl cellulose/sodium alginate nanocomposite films: Assessment of physicochemical and antibacterial properties

Incorporating single or combined nanofillers in polymeric matrices is a promising approach for developing antimicrobial materials for applications in wound healing and packaging etc. This study reports a facile fabrication of antimicrobial nanocomposite films using biocompatible polymers sodium carboxymethyl cellulose (CMC) and sodium alginate (SA) reinforced with nanosilver (Ag) and graphene oxide (GO) using the solvent casting approach. Eco-friendly synthesis of Ag nanoparticles within a size range of 20-30 nm was carried out within the polymeric solution. GO was introduced into the CMC/SA/Ag solution in different weight percentages. The films were characterized by UV-Vis, FT-IR, Raman, XRD, FE-SEM, EDAX, and TEM. The results indicated the enhanced thermal and mechanical performance of CMC/SA/Ag-GO nanocomposites with increased GO weight %. The antibacterial efficacy of the fabricated films was evaluated on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The CMC/SA/Ag-GO2% nanocomposite exhibited the highest zone of inhibition of 21.30 ± 0.70 mm against E. coli and 18.00 ± 1.00 mm against S. aureus. The CMC/SA/Ag-GO nanocomposites exhibited excellent antibacterial activity as compared to CMC/SA and CMC/SA-Ag due to the synergetic bacterial growth inhibition activities of the GO and Ag. The cytotoxic activity of the prepared nanocomposite films was also assessed to investigate their biocompatibility.

NIR irradiation enhances the apoptotic potentiality of quinacrine-gold hybrid nanoparticles by modulation of HSP-70 in oral cancer stem cells

Cancer stem cells (CSCs) are the tumor cell subpopulations that can self-renew, differentiate, initiate and maintain tumor growth. CSCs are frequently drug-resistant, resulting in tumor recurrence, metastasis, and angiogenesis. Herein, using in vitro oral squamous cell carcinoma (OSCC) CSCs and in vivo xenograft mice model, we have systematically studied the apoptotic potentiality of quinacrine-gold hybrid nanoparticle (QAuNP) and its underlying mechanism after NIR irradiation. QAuNP + NIR caused DNA damage and induced apoptosis in SCC-9-CSCs by deregulating mitochondrial membrane potential (ΔΨm) and activation of ROS. Upregulation of CASPASE-3 and DR-5/DR-4 and reduction of heat shock protein (HSP-70) up to 5-fold were also noticed upon the treatment. The increased expression of DR-5 and CASPASE-3 and decreased expression of HSP-70, CD-44 and Ki-67 were also noted in the xenograft mice treated with QAuNP + NIR + TRAIL. Thus, data suggest that the combined treatment enhances apoptosis in OSCC-CSCs by modulating HSP-70 in the DISC.

PARP inhibitor BMN-673 induced apoptosis by trapping PARP-1 and inhibiting base excision repair via modulation of pol-β in chromatin of breast cancer cells

PARP inhibitors emerged as clinically effective anti-tumor agents in combination with DNA damaging agents but the toxicity of DNA damaging agents and their off-target effects caused serious problems in cancer therapy. They confer cytotoxicity in cancer cells both by catalytic inhibition and trapping of PARP-1 at the DNA damage site. There is a lack of direct evidence to quantitatively determine the trapped PARP-1 in cellular DNA. Here, we have precisely evaluated the mechanism of PARP trapping mediated anti-cancer action of Quinacrine (QC), BMN-673, and their combination (QC + BMN-673) in breast cancer cells. We introduced a strategy to measure the cellular PARP trapping potentiality of BMN-673 in QC pretreated cells using a fluorescence-based assay system. It was found that QC+ BMN-673 induced apoptosis by triggering DNA damage in breast cancer cells. Treatment with QC + BMN-673 stimulated the expression of PARP-1 in the chromatin compared to that of PARP-2 and PARP-3. QC + BMN-673 treatment also caused a dose-dependent and time-dependent accumulation of PARP-1 and inhibition of PARylation in the chromatin. Upregulation of BER components (pol-β and FEN-1), an unchanged HR and NHEJ pathway proteins, and reduction of luciferase activity of the cells transfected with R-p21-P (LP-BER) were noted in combined drug-treated cells. Interestingly, silencing of pol-β resulted in unchanged PARP-1 trapping and PAR activity in the chromatin with increasing time after QC + BMN-673 treatment without altering APC and FEN-1 expression. Thus, our data suggested that the QC + BMN-673 augmented breast cancer cell death by pol-β mediated repair inhibition primarily through trapping of PARP-1 besides PARP-1 catalytic inhibition.

Nectin-4 promotes lymphangiogenesis and lymphatic metastasis in breast cancer by regulating CXCR4-LYVE-1 axis

Tumor-induced lymphangiogenesis promotes tumor progression by generating new lymphatic vessels that helps in tumor dissemination to regional lymph nodes and distant sites. Recently, the role of Nectin-4 in cancer metastasis and angiogenesis has been studied, but its role in lymphangiogenesis is unknown. Here, we systematically delineated the role of Nectin-4 in lymphangiogenesis and its regulation in invasive duct carcinoma (IDC). Nectin-4 expression positively correlated with occurrence risk factors associated with breast cancer (alcohol, smoke, lifestyle habit, etc), CXCR4 expression, and LYVE-1-lymphatic vessel density (LVD). LVD was significantly higher in axillary lymph node (ALN) than primary tumor. Depleting Nectin-4, VEGF-C or both attenuated the important lymphangiogenic marker LYVE-1 expression, tube formation, and migration of ALN derived primary cells. Nectin-4 stimulated the expressions of CXCR4 and CXCL12 under hypoxic conditions in ALN derived primary cells. Further, Nectin-4 augmented expressions of lymphatic metastatic markers (e.g. eNOS, TGF-β, CD-105) and MMPs. Induced expressions of Nectin-4 along with other representative metastatic markers were noted in lymph and blood circulating tumor cells (LCTCs and BCTCs) of local and distant metastatic samples. Thus, Nectin-4 displayed a predominant role in promoting tumor-induced lymphangiogenesis and lymphatic metastasis by modulating CXCR4/CXCL12-LYVE-1- axis.

Olaparib enhances curcumin-mediated apoptosis in oral cancer cells by inducing PARP trapping through modulation of BER and chromatin assembly

Apart from inducing catalytic inhibition of PARP-1, PARP inhibitors can also trap PARP proteins at the sites of DNA damage and forming toxic PARP-DNA complexes. These complexes obstruct the DNA repair process, resulting in cancer cell death. To study the detailed mechanism of anti-cancer action through PARP trapping, we have treated oral cancer cells (H-357) with curcumin (Cur), olaparib (Ola) and their combination (Cur + Ola). Cur + Ola treatment triggered the expressions of PARP-1 and adenomatous polyposis coli (APC) and down regulated other base excision repair (BER) proteins in the chromatin fraction but not in the nuclear fraction. Cur + Ola treatment inhibited PARylation, altered interaction of PARP-1 with representative BER proteins and arrested cells in S-phase. We have for the first time provided direct evidence and measured the cellular PARP-1 trapping potentiality of Ola in Cur pretreated H-357 cells. Unchanged cellular PARP-1 trapping, unaltered expression of BER proteins and BER activity were found in APC silenced H-357 cells, which further confirmed that the DNA damage/repair response was APC-dependent. Interestingly, complete abolishment of the chromatin remodeler 'amplified in Liver Cancer 1' (ALC1), decreased expression of Histone H3 and histone acetyltransferase (P300) was noted in chromatin of Cur + Ola treated cells. Their expressions remained unchanged in APC silenced cells. Cur + Ola also altered the interaction of ALC1 with BER proteins including APC. Thus, the present study reveals that Cur + Ola treatment increased oral cancer cell death not only through catalytic inhibition of PARP-1 but also predominantly through PARP-1 trapping and indirect inhibition of chromatin remodeling.

Nano formulated Resveratrol inhibits metastasis and angiogenesis by reducing inflammatory cytokines in oral cancer cells by targeting tumor associated macrophages

Tumor associated macrophages in the tumor microenvironment secrete multiple cytokines, which regulate cancer cells growth and invasiveness. We systematically studied the role of cytokines in the induction of cancer stem like cells (CSCs) in oral cancer cells niche and evaluated the mechanism of Resveratrol nanoparticle (Res-Nano) mediated-reduction of CSCs properties in cells. A highly M1-like macrophages-enriched conditioned medium (CM) was generated by treating fixed doses of PMA and LPS in THP-1 cells alone as well as co-cultured of H-357 plus THP-1 cells. These M1-like macrophages increased the production of cytokines (e.g., TNF-α, IL-6, IL-1β, etc.). A CSCs populated environment was created after addition of cytokine-enriched-CM of co-culture of H-357 and THP-1 cells to cancer cells and cytokine enriched CM of THP-1 cells to patient derived primary oral cancer cells, respectively. After incubation with CM, enhancement of stemness, angiogenic and metastatic properties of both H-357 and primary oral cancer cells were noted. Res-NP decreased the cytokines level in CSCs-enriched cells and reduced the invasion, proliferation and growth of CSCs. Representative metastatic (CD133, ALDH1, CXCR4, etc.) and angiogenic markers (MMPs, iNOS, VEGF-A, etc.) were decreased after Res-NP treatment in CSCs enriched oral cancer cells niche. It also disrupted angiogenesis, depleted nitric oxide production in fertilized chick embryos and reduced the expression of metastatic and angiogenic markers in xenograft mice model system. Thus, this study concluded that CSCs-mediated stemness is a cytokine dependent phenomena and treatment of Res-NP inhibit this process in in vitro, in vivo and ex vivo systems.

5-Fluorouracil (5-FU) resistance and the new strategy to enhance the sensitivity against cancer: Implication of DNA repair inhibition

5-Fluorouracil (5-FU) has been an important anti-cancer drug to date. With an increase in the knowledge of its mechanism of action, various treatment modalities have been developed over the past few decades to increase its anti-cancer activity. But drug resistance has greatly affected the clinical use of 5-FU. Overcoming this chemoresistance is a challenge due to the presence of cancer stem cells like cells, cancer recurrence, metastasis, and angiogenesis. In this review, we have systematically discussed the mechanism of 5-FU resistance and advent strategies to increase the sensitivity of 5-FU therapy including resistance reversal. Special emphasis has been given to the cancer stem cells (CSCs) mediated 5-FU chemoresistance and its reversal process by different approaches including the DNA repair inhibition process.

Quinacrine Based Gold Hybrid Nanoparticles Caused Apoptosis through Modulating Replication Fork in Oral Cancer Stem Cells

The presence of cancer stem cells (CSCs) in the tumor microenvironment is responsible for the development of chemoresistance and recurrence of cancer. Our previous investigation revealed the anticancer mechanism of quinacrine-based silver and gold hybrid nanoparticles (QAgNP and QAuNP) in oral cancer cells, but to avoid cancer recurrence, it is important to study the effect of these nanoparticles (NPs) on CSCs. Here, we developed an in vitro CSCs model using SCC-9 oral cancer cells and validated via FACS analysis. Then, 40-60% of cells were found to be CD44+/CD133+ and CD24-. QAuNP showed excellent anti-CSC growth potential against SCC-9-cancer stem like cells (IC₅₀ = 0.4 μg/mL) with the down-regulation of representative CSC markers. Prolonged exposure of QAuNP induced the S-phase arrest and caused re-replication shown by the extended G2/M population and apoptosis to SCC-9-CSC like cells. Up-regulation of BAX, PARP cleavage, and simultaneous down-regulation of Bcl-xL in prolonged treatment to CSCs suggested that the majority of the cells have undergone apoptosis. QAuNP treatment also caused a loss in DNA repair in CSCs. Mostly, the base excision repair (BER) components (Fen-1, DNA ligase-1, Pol-β, RPA, etc.) were significantly down-regulated after QAuNP treatment, which suggested its action against DNA repair machinery. The replication fork maintenance-related proteins, RAD 51 and BRCA-2, were also deregulated. Very surprisingly, depletion of WRN (an interacting partner for Pre-RC and Fen-1) and a significant increase in expression of fork-degrading nuclease MRE-11 in 96 h treated NPs were observed. Results suggest QAuNP treatment caused excessive DNA damage and re-replication mediated replication stress (RS) and stalling of the replication fork. Inhibition of BER components hinders the flap clearance activity of Fen-1, and it further caused RS and stopped DNA synthesis. Overall, QAuNP treatment led to irreparable replication fork movement, and the stalled replication fork might have degraded by MRE-11, which ultimately results in apoptosis and the death of the CSCs.

Clinical significance of a pvrl 4 encoded gene Nectin-4 in metastasis and angiogenesis for tumor relapse

PURPOSE

In the present study, we have systematically examined the clinical significance of Nectin-4 (encoded by the PVRL-4 gene), a marker for breast cancer stem cells (CSCs), in cancer metastasis and angiogenesis using a variety of human specimens, including invasive duct carcinoma (IDC) with multiple grades, several types of primary tumors to local and distant relapses, lymph node metastases and circulating tumor cells (CTCs).

METHODS

Nectin-4 was overexpressed in more than 92% of samples with 65.2% Nectin-4-positive cells. The level of expression was increased with increasing tumor grade (GI-III) and size (T1-4) of IDC specimens.

RESULTS

More induction of Nectin-4 was noted in relapsed samples from a variety of tumors (colon, tongue, liver, kidney, ovary, buccal mucosa) in comparison to primary tumors, while paired adjacent normal tissues do not express any Nectin-4. A high expression of Nectin-4 along with other representative markers in CTCs and lymph node metastasis was also observed in cancer specimens. An increased level of Nectin-4 along with representative metastatic (CD-44, Sca1, ALDH1, Nanog) and angiogenic (Ang-I, Ang-II, VEGF) markers were noted in metastatic tumors (local and distant) in comparison to primary tumors that were correlated with different grades of tumor progression. In addition, greater expression of Nectin-4 was observed in secondary tumors (distant metastasis, e.g., breast to liver or stomach to gall bladder) in comparison to primary tumors.

CONCLUSION

Our study demonstrated a significant correlation between Nectin-4 expression and tumor grade as well as stages (p < 0.001), suggesting its association with tumor progression. Nectin-4 was overexpressed at all stages of metastasis and angiogenesis, thus appearing to play a major role in tumor relapse through the PI3K-Akt-NFκβ pathway.

Nanoquinacrine sensitizes 5-FU-resistant cervical cancer stem-like cells by down-regulating Nectin-4 via ADAM-17 mediated NOTCH deregulation

PURPOSE

Cervical cancer is a major cause of cancer-related death in women world-wide. Although the anti-metabolite 5-FU is widely used for its treatment, its clinical utility is limited due to the frequent occurrence of drug resistance during metastasis. Cancer stem-like cells (CSCs), present in the heterogeneous population of CC cells, are thought to contribute to this resistance. Nectin-4, a CSC marker, is known to play an important role in the cellular aggressiveness associated with metastatic CC. This study was designed to assess the role of Nectin-4 in the acquisition of 5-FU resistance by metastatic CC cells, including its relation to the NOTCH signalling pathway.

METHODS

5FU-resistant CC cell lines were deduced from ME-180 and SiHA cells by continuous exposure to a single concentration of 5-FU. Thymidylate synthase (TS) positive cells were isolated from the 5-FU resistant cells, after which a metastatic model was developed. The role of Nectin-4 in the sensitization of 5-FU resistant metastatic CC cells upon incubation with Nano-formulated Quinacrine (NQC) was investigated using multiple bioassays including MTT, FACS, ELISA, immunoflurescence, Western blotting, comet and in vivo plasmid-based short patch and long patch base excision repair assays.

RESULTS

We found that the expression level of Nectin-4, as well as that of other CSC markers (Oct-4, β-catenin, SOX2) and representative NOTCH signalling components (NOTCH-1, Jagged-1, γ-secretase, ADAM-17) were elevated in the 5-FU resistant metastatic cells compared to those in control cells. Increased nuclear translocation of Nectin-4 and increased proliferation and invasion rates were observed after culturing the metastatic cells under hypoxic conditions. Treatment with NQC inhibited the nuclear translocation of Nectin-4 and decreased the proliferation and invasion rates of the cells by inhibiting the induction of base excision repair (BER) pathway components and ADAM-17 expression levels. After combination treatment of Nectin-4 overexpressing metastatic CC cells with a specific ADAM-17 inhibitor (GW280264) and NQC, a decreased Nectin-4 expression, without alterations in BER and/or other NOTCH pathway components, was noted.

CONCLUSION

Our data indicate that Nectin-4 may play a prominent role in 5-FU resistance of metastatic CC cells and that NQC sensitizes these cells by Nectin-4 deregulation through ADAM-17 inhibition, a major component of the NOTCH signalling pathway.

Nectin-4 is a breast cancer stem cell marker that induces WNT/β-catenin signaling via Pi3k/Akt axis

Nectin-4 is well known as a junction protein. Recent reports have implicated it in cancer, but there has been little exploration of its functional significance in metastasis and cancer stem cells. Here, using the breast cancer metastasis model system, we report Nectin-4 is a marker for breast cancer stem cells (BCSCs) and provide experimental evidence suggesting that it utilizes WNT/β-Catenin signaling via Pi3k/Akt axis for self renewal of BCSCs. In vitro, in vivo, ex vivo and clinical pathological data showed upregulated Nectin-4 in breast cancer metastasis and WNT/β-Catenin signaling. Nectin-4 depletion inhibited EMT, metastasis, invasion, and the WNT/β-Catenin pathway; conversely, Nectin-4 overexpression in null cells upregulated EMT and metastasis and also induced WNT/β-Catenin signaling via Pi3k/Akt axis, which in turn, controls cancer stem cell proliferation. Induced Nectin-4 was observed in breast tumor patient samples and in breast tumor metastases to axillary lymph nodes, which indicated that Nectin-4 is not only a BCSC marker but also a breast cancer metastasis marker. The current study provides clear evidence that Nectin-4 is a BCSC marker and is responsible for breast cancer metastasis.