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Background: Squamous cell carcinoma of the oral cavity (SCCOC) is the dominant origin of cancer associated mortality. Previous findings by our study reported that acquisition of anoikis resistance has a significant role in tumor progression of oral cavity. Several genes were over-expressed in anoikis-resistant cells under detached conditions which we confirmed earlier by microarray. Normal oral squamous epithelia grow adherent to a basement membrane, and when detached from the extracellular matrix, undergoes programmed cell death. The acquisition of anoikis-resistance is crucial phenomena in oral tumor advancement. In the current study, we have identified S100A7 expression as contributing factor for anoikis resistance and tumorigenicity in human oral cancer cells. Further, we have explored that elevated S100A7 expression in anoikis-sensitive oral keratinocytes and cancer cells reshape them more resistant to anoikis and apoptosis inducers via activation of cellular intrinsic and extrinsic avenue. Methods: A subset of human cancer cell lines TU167, JMAR, JMARC39, JMARC42 and MDA-MB-468 were utilized for the generation of resistant stable cell lines. Further, immunohistochemistry, western blot and immunoprecipitation, assays of apoptosis, soft agar assay, orthotopic animal model and signaling elucidation were performed to establish our hypothesis. Results: S100A7 gene is found to be responsible for anoikis resistance and tumorigenicity in human oral cancer cells. We have observed up-regulation of S100A7 in anoikis resistant cell lines, orthotropic model and patients samples with head and neck cancer. It is also noticed that secretion of S100A7 protein in conditioned medium by anoikis resistant head & neck cancer cell and in saliva of head and neck cancer patients. Up-regulation of S100A7 expression has triggered enhanced tumorigenicity and anchorage-independent growth of cancer cells through Akt phosphorylation leading to development of aniokis resistance in head and neck cancer cells. Conclusions: These data have led us to conclude that S100A7 is the major contributing factor in mediating anoikisresistance of oral cancer cells and local tumor progression, and S100A7 might be useful as diagnostic marker for early detection of primary and recurrent squamous cell cancer. [ABSTRACT FROM AUTHOR]

Background: Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs.Methods: The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed.Results: Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment.Conclusions: Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive combination of TAM and CXB is a potential drug candidate for treatment of breast tumors expressing high levels of VEGF and VEGFR2. This ingenious combination might be a better tailored clinical regimen than TAM alone for breast cancer treatment. [ABSTRACT FROM AUTHOR]

Cellular redox changes have emerged as a pivotal and proximal event in cancer. PKI 166 is used to determine the effects of redox sensitive inhibition of EGFR, metastasis and apoptosis in epidermoid carcinoma. Cytotoxicity study of PKI 166 (IC50 1.0 µM) treated A431 cells were performed by MTT assay for 48 and 72 hrs. Morphological analysis of PK1166 treated A431 cells for 48 hrs. revealed the cell shrinkage, loss of filopodia and lamellipodia by phase contrast and SEM images in dose dependent manner. It has cytotoxic effects through inhibiting cellular proliferation, leads to the induction of apoptosis, as increased fraction of sub-G, phase of the cell cycle, chromatin condensation and DIMA ladder. It inhibited cyclin-D1 and cyclin-E expression and induced p53, p21 expression in dose dependent manner. Consequently, an imbalance of Bax /Bcl-2 ratio triggered caspase cascade and subsequent cleavage of PARP, thereby shifting the balance in favour of apoptosis. PKI 166 treatment actively stimulated reactive oxygen species (ROS) and mitochondrial membrane depolarization. It inhibited some metastatic properties of A431 cells supressing colony formation by soft agar assay and inhibition of MMP 9 activity by gelatin zymography and western blot analysis. PK1166 inhibited growth factor induced phosphorylation of EGFR, Akt, MAPK, JNK and colony formation in A431 cells. Thus the inhibition of proliferation was associated with redox regulation of the caspase cascade, EGFR, Akt/PI3K, MAPK/ ERK and JNK pathway. On the other hand, increased antioxidant activity leads to decreased ROS generation inhibit the anti-proliferative and apoptotic properties of PK1166 in A431 cells. These observations indicated PKI 166 induced redox signalling dependent inhibition of cell proliferation, metastatic properties and induction of apoptotic potential in epidermoid carcinoma. [ABSTRACT FROM AUTHOR]

Abstract: Aim: Thymoquinone (TQ), the predominant bioactive constituent of black seed oil (Nigella Sativa), has been shown to possess antineoplastic activity against multifarious tumors. However, the meticulous mechanism of TQ on Akt mediated survival pathway is still unrevealed in breast cancer. Here, we investigated TQ's mechanism of action against PI3K/Akt signaling and its downstream targets by modulating proteins translational machinery, leading to apoptosis in cancer cells. Main methods: MDA-MB-468 and T-47D cells were treated with TQ and evaluated for its anticancer activity through phase distribution and western blot. Modulatory effects of TQ on Akt were affirmed through kinase and drug potential studies. Key findings: Studies revealed G1 phase arrest till 24h incubation with TQ while extended exposure showed phase shift to subG1 indicating apoptosis, supported by suppression of cyclin D1, cyclin E and cyclin dependent kinase inhibitor p27 expression. Immunoblot and membrane potential studies revealed mitochondrial impairment behind apoptotic process with upregulation of Bax, cytoplasmic cytochrome c and procaspase-3, PARP cleavage along with Bcl-2, Bcl-xL and survivin downregulation. Moreover, we construed the rationale behind mitochondrial dysfunction by examining the phosphorylation status of PDK1, PTEN, Akt, c-raf, GSK-3? and Bad in TQ treated cells, thus ratifying the involvement of Akt in apoptosis. Further, the consequential effect of Akt inhibition by TQ is proven by translational repression through deregulated phosphorylation of 4E-BP1, eIF4E, S6R and p70S6K. Significance: Our observations for the first time may provide a new insight for the development of novel therapies for Akt overexpressed breast cancer by TQ. [Copyright &y& Elsevier]

Epithelial to mesenchymal transition (EMT) and extracellular matrix (ECM) remodeling, are the two elemental processes promoting glioblastoma (GBM). In the present work we propose a mechanistic modelling of GBM and in process establish a hypothesis elucidating critical crosstalk between heat shock proteins (HSPs) and matrix metalloproteinases (MMPs) with synergistic upregulation of EMT-like process and ECM remodeling. The interaction and the precise binding site between the HSP and MMP proteins was assayed computationally, in-vitro and in GBM clinical samples. A positive crosstalk of HSP27 with MMP-2 and MMP-9 was established in both GBM patient tissues and cell-lines. This association was found to be of prime significance for ECM remodeling and promotion of EMT-like characteristics. In-silico predictions revealed 3 plausible interaction sites of HSP27 interacting with MMP-2 and MMP-9. Site-directed mutagenesis followed by in-vitro immunoprecipitation assay (IP) with 3 mutated recombinant HSP27, confirmed an interface stretch containing residues 29–40 of HSP27 to be a common interaction site for both MMP-2 and MMP-9. This was further validated with in-vitro IP of truncated (sans AA 29–40) recombinant HSP27 with MMP-2 and MMP-9. The association of HSP27 with MMP-2 and MMP-9 proteins along with the identified interacting stretch has the potential to contribute towards drug development to inhibit GBM infiltration and migration. Current findings provide a novel therapeutic target for GBM opening a new horizon in the field of GBM management. Unlabelled Image • Root cause for glioblastoma high infiltrative potential is yet unknown and no clear way to prevent it. • Association between MMPs and HSPs with infiltrative potential was revealed by deciphering novel and vital interaction among of HSP27 with MMP-2 and MMP-9. • Study presented HSP27 promoting EMT-like features in glioblastoma tumor cells through a direct interaction with MMP-2 and MMP-9 at an interface site AA29–40 of HSP27. • Our findings contribute towards precise drug development for inhibiting GBM infiltration and migration. [ABSTRACT FROM AUTHOR]

Mass spectrometry (MS) has become a mainstream platform for comprehensive profiling of proteome, especially with the improvement of multiplexed tandem mass tag labeling coupled with two-dimensional liquid chromatography and tandem mass spectrometry (TMT-LC/LC-MS/MS). Recently, we have established a robust method for direct profiling of undepleted cerebrospinal fluid (CSF) proteome with the 16-plex TMTpro method, in which we optimized parameters in experimental steps of sample preparation, TMT labeling, LC/LC fractionation, tandem mass spectrometry, and computational data processing. The extensive LC fractionation not only enhances proteome coverage of the CSF but also alleviates ratio distortion of TMT quantification. The crucial quality control steps and improvements specific for the TMT16 analysis are highlighted. More than 3000 proteins can be quantified in a single experiment from 16 different CSF samples. This multiplexed method offers a powerful tool for profiling a variety of complex biofluids samples such as CSF, serum/plasma, and other clinical specimens., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Amplification of PI3K-Akt pathway promotes radioresistance in various cancers including colorectal carcinoma. Local recurrence in colon cancer causes poor prognosis affecting overall survival of cancer-affected patient population. To avoid local recurrence, pre-operative or post-operative additional radiotherapy is given. However, main concern regarding radiotherapy is to increase the radiosensitivity of malignant cell without hampering the activities of normal cells. In this context, addition of two or more than two chemotherapeutic drugs as a radiosensitizer is a common practice in radiation biology. BI-69A11 earlier showed potential apoptosis-inducing effect in melanoma and colon carcinoma. Celecoxib showed anti-cancer effects in both COX-2 dependent and independent pathways and used to act as a radiosensitizing enhancer. Here, we suggest that the combination of BI-69A11 and celecoxib inhibits the phosphorylation of ataxia telangiectasia mutated (ATM) kinase and DNA-PK responsible for ionizing radiation (IR)-induced double-strand break (DSB) repair. Moreover, the combinatorial effect of BI-69A11 and celecoxib attenuates the IR-induced G2/M cell cycle arrest. Furthermore, this combination also impairs IR-induced activation of Akt and downstream targets of ATM. This might lead to induced activation of apoptotic pathway after triple therapy treatment modulating pro-apoptotic and anti-apoptotic proteins. This activation of apoptotic pathway also showed the interdependence of PUMA and BAD in triple combination-treated colon cancer cells in a p53 independent manner. This study reveals the therapeutic potential of the triple combination therapy in prevention of radioresistance. Besides, it also demonstrates the cytotoxic effects of triple combination therapy in colon cancer. This study shows utility and potential implication on safety of the patients undergoing radiation therapy.