Cisplatin and PI3kinase inhibition decrease invasion and migration of human ovarian carcinoma cells and regulate matrix-metalloproteinase expression

Fc-mediated immune stimulating, pro-inflammatory and antitumor effects of anti-HER2 IgE against HER2-expressing and trastuzumab-resistant tumors

BACKGROUND

Anti-human epidermal growth factor receptor 2 (HER2) IgG1-based antibody therapies significantly improve cancer prognosis, yet intrinsic or acquired resistance to fragment antigen-binding (Fab)-mediated direct effects commonly occurs. Most resistant tumors retain antigen expression and therefore remain potentially targetable with anti-HER2 therapies that promote immune-mediated responses. Tumor-antigen-specific IgE class antibodies can mediate powerful immune cell-mediated effects against different cancers and have been shown to activate IgE Fc receptor-expressing monocytes. We previously reported the engineering of a trastuzumab-equivalent anti-HER2 IgE antibody and showed early evidence of Fc-mediated cancer cell-targeting effects. In the present study, we evaluated the anti-tumoral functions of two anti-HER2 IgEs, trastuzumab and pertuzumab IgE.

METHODS

In vitro functionality of the two anti-HER2 antibodies was assessed by HER2 phosphorylation and ligand-independent viability assays, as well as basophil (RBL-SX38) degranulation, antibody-dependent cellular cytotoxicity/antibody-dependent cellular phagocytosis(ADCC/ADCP) assays and primary monocyte stimulation assays. The potential to trigger a hypersensitivity type I reaction was investigated using the basophil activation test (BAT). anti-tumoral efficacy was assessed in two humanized HER2+, trastuzumab-resistant models in vivo. Changes in the tumor microenvironment were assessed by flow cytometry or bulk RNA sequencing.

RESULTS

We demonstrate the anti-tumoral and immunostimulatory functions of two anti-HER2 IgEs derived from variable region sequences of the clinically available trastuzumab and pertuzumab IgG1 antibodies. IgE engagement of monocytes via the Fc region induced tumor cell cytotoxicity and a pro-inflammatory shift with upregulation of immune-stimulatory CD40, CD80 and CD86, and downregulation of scavenger CD163, cell surface molecules. This was accompanied by enhanced pro-inflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β cytokine production. The absence of basophil activation by anti-HER2 IgEs ex vivo in whole blood points to potentially safe administration in humans. In two trastuzumab-resistant HER2+ tumor xenograft models in immunodeficient mice reconstituted with human immune cells, the trastuzumab-equivalent anti-HER2 IgE restricted tumor growth. Treatment was associated with enriched classical (CD14+CD16-) monocyte and lower alternatively-activated (CD163+CD206+) macrophage infiltration, and higher densities of activated CD4+ (CD127loCD25hi) T cells and favorable effector T cell(Teff) to regulatory T cell (Treg) ratios in tumors.

CONCLUSION

Collectively, anti-HER2 IgE maintains Fab-mediated antitumor activity, induces Fc-mediated effects against HER2-expressing tumor cells, and stimulates remodeling of the immune microenvironment in tumors to promote pro-inflammatory cell phenotypes which could translate to improved outcomes for patients.

Carotenoids as modulators of the PI3K/Akt/mTOR pathway: innovative strategies in cancer therapy

Cancer progression is primarily driven by the uncontrolled activation of cellular signaling pathways, with the PI3K/Akt/mTOR (PAMT) pathway playing a central role. This pathway significantly contributes to the proliferation and survival of cancer cells, and its hyperactivity is a major challenge in managing several types of malignancies. This article delves into the promising potential of carotenoids, natural pigments found in abundance in fruits and vegetables, as a novel therapeutic strategy for cancer treatment. By specifically targeting and inhibiting the PAMT pathway, carotenoids may effectively disrupt the growth and survival of cancer cells. The article examines the complex mechanisms underlying these interactions and highlights the obstacles faced in cancer treatment. It proposes a compelling approach to developing therapies that leverage natural products to target this critical pathway, offering a fresh perspective on cancer treatment. Further research is essential to enhance the therapeutic efficacy of these compounds.

Matrix metalloproteinases as the critical regulators of cisplatin response and tumor cell invasion

Cisplatin (CDDP) as one of the most common first-line chemotherapy drugs plays a vital role in the treatment of a wide range of malignant tumors. Nevertheless, CDDP resistance is observed as a therapeutic challenge in a large number of cancer patients. Considering the CDDP side effects in normal tissues, predicting the CDDP response of cancer patients can significantly help to choose the appropriate therapeutic strategy. In this regard, investigating the molecular mechanisms involved in CDDP resistance can lead to the introduction of prognostic markers in cancer patients. Matrix metalloproteinases (MMPs) have critical roles in tissue remodeling and cell migration through extracellular matrix degradation. Therefore, defects in MMPs functions can be associated with tumor metastasis and chemo resistance. In the present review, we discussed the role of MMPs in CDDP response and tumor cell invasion. PubMed, Scopus, Google Scholar, and Web of Science were searched using "MMP", "cisplatin", and "cancer" keywords for data retrieval that was limited to Apr 20, 2024. It has been reported that MMPs can increase CDDP resistance in tumor cells as the effectors of PI3K/AKT, MAPK, and NF-κB signaling pathways or independently through the regulation of structural proteins, autophagy, and epithelial-to-mesenchymal transition (EMT) process. This review has an effective role in introducing MMPs as the prognostic markers and therapeutic targets in CDDP-resistant cancer patients.

Antimetastatic activity of (arene)ruthenium(II) complex of 4-aryl-4H-naphthopyran

Metastatic cancer remains a formidable challenge in anticancer therapy. Despite efforts to develop effective antimetastasis drugs over the past half-century, currently approved treatments fall short of expectations. This report highlights the promising antiproliferative activity of a ruthenium-based therapeutic agent, namely dichlorido(p-cymene)[2-amino-4-(pyridin-3-yl)-4H-benzo[h]-chromene-3-carbonitrile]ruthenium(II) (complex 1) against metastatic cell lines. Complex 1 shows significant efficacy in metastatic LoVo and Du-145 cell lines at nanomolar concentrations, being markedly more active than clinically used anticancer cisplatin. Studies on the MDA-MB-231 cell line, which displays invasive characteristics, demonstrated that 1 significantly reduces cell invasion. This efficacy was confirmed by its impact on matrix metalloproteinase production in MDA-MB-231 cells. Given that cell migration drives cancer invasion and metastasis, complex 1's effect on MDA-MB-231 cell migration was evaluated via wound healing assay and vimentin network analysis. Results indicated a strong reduction in migration. A re-adhesion assay further demonstrated that 1 significantly lowers the re-adhesion ability of MDA-MB-231 cells compared to cisplatin. To better simulate the human body environment, a 3D spheroid invasion assay was used. This method showed that 1 effectively inhibits tumor spheroids from infiltrating the surrounding extracellular matrix. This study underscores the potential of (arene)ruthenium(II) complexes with naphthopyran ligands as potent antimetastatic agents for chemotherapy.

A bioinformatics framework to identify the biomarkers and potential drugs for the treatment of colorectal cancer

Colorectal cancer (CRC), a common malignant tumor, is one of the main causes of death in cancer patients in the world. Therefore, it is critical to understand the molecular mechanism of CRC and identify its diagnostic and prognostic biomarkers. The purpose of this study is to reveal the genes involved in the development of CRC and to predict drug candidates that may help treat CRC through bioinformatics analyses. Two independent CRC gene expression datasets including The Cancer Genome Atlas (TCGA) database and GSE104836 were used in this study. Differentially expressed genes (DEGs) were analyzed separately on the two datasets, and intersected for further analyses. 249 drug candidates for CRC were identified according to the intersected DEGs and the Crowd Extracted Expression of Differential Signatures (CREEDS) database. In addition, hub genes were analyzed using Cytoscape according to the DEGs, and survival analysis results showed that one of the hub genes, TIMP1 was related to the prognosis of CRC patients. Thus, we further focused on drugs that could reverse the expression level of TIMP1. Eight potential drugs with documentary evidence and two new drugs that could reverse the expression of TIMP1 were found among the 249 drugs. In conclusion, we successfully identified potential biomarkers for CRC and achieved drug repurposing using bioinformatics methods. Further exploration is needed to understand the molecular mechanisms of these identified genes and drugs/small molecules in the occurrence, development and treatment of CRC.

Lactate-related metabolic reprogramming and immune regulation in colorectal cancer

Changes in cellular metabolism involving fuel sources are well-known mechanisms of cancer cell differentiation in the context of carcinogenesis. Metabolic reprogramming is regulated by oncogenic signaling and transcriptional networks and has been identified as an essential component of malignant transformation. Hypoxic and acidified tumor microenvironment contributes mainly to the production of glycolytic products known as lactate. Mounting evidence suggests that lactate in the tumor microenvironment of colorectal cancer(CRC) contributes to cancer therapeutic resistance and metastasis. The contents related to the regulatory effects of lactate on metabolism, immune response, and intercellular communication in the tumor microenvironment of CRC are also constantly updated. Here we summarize the latest studies about the pleiotropic effects of lactate in CRC and the clinical value of targeting lactate metabolism as treatment. Different effects of lactate on various immune cell types, microenvironment characteristics, and pathophysiological processes have also emerged. Potential specific therapeutic targeting of CRC lactate metabolism is also discussed. With increased knowledge, effective druggable targets might be identified, with the aim of improving treatment outcomes by reducing chemoresistance.

A375 melanoma cells are sensitized to cisplatin-induced toxicity by a synthetic nitro-flavone derivative 2-(4-Nitrophenyl)-4H-chromen-4-one through inhibition of PARP1

BACKGROUND

Cisplatin has been extensively used in therapeutics for its broad-spectrum anticancer activity and frequently used for the treatment of solid tumors. However, it presents several side-effects and several cancers develop resistance. Combination therapy of cisplatin with poly (ADP-ribose) polymerase 1 (PARP1) inhibitors has been effective in increasing its efficacy at lower doses.

METHODS AND RESULTS

In this work, we have shown that the nitro-flavone derivative, 2-(4-Nitrophenyl)-4H-chromen-4-one (4NCO), can improve the sensitivity of cancer cells to cisplatin through inhibition of PARP1. The effect of 4NCO on cisplatin toxicity was studied through combination therapy in both exponential and density inhibited A375 melanoma cells. Combination index (CI) was determined from isobologram analysis. The mechanism of cell killing was assessed by lactate dehydrogenase (LDH) assay. Temporal nicotinamide adenine dinucleotide (NAD⁺) assay was done to show the inhibition of PARP1. We also performed in silico molecular modeling studies to know the binding mode of 4NCO to a modeled PARP1-DNA complex containing cisplatin-crosslinked adduct. The results from both in silico and in cellulo studies confirmed that PARP1 inhibition by 4NCO was most effective in sensitizing A375 melanoma cells to cisplatin. Isobologram analysis revealed that 4NCO reduced cell viability both in exponential and density inhibited A375 cells synergistically. The combination led to cell death through apoptosis.

CONCLUSION

The synthetic nitro-flavone derivative 4NCO effectively inhibited the important nuclear DNA repair enzyme PARP1 and therefore, could complement the DNA-damaging anticancer drug cisplatin in A375 cells and thus, could act as a potential adjuvant to cisplatin in melanoma therapy.

The role of MMP-14 in ovarian cancer: a systematic review

AIM

In order to evaluate the role of MMP-14 in ovarian cancer, a systematic review was conducted.

METHODS

In March 2020, a search in Pubmed was performed with MMP-14 and ovarian cancer as search terms. After exclusion of the references not on MMP-14 or ovarian cancer or not in English, the studies found were classified into two categories: basic research and clinicopathological research.

RESULTS

In total, 94 references were found of which 33 were excluded. Two additional articles were found in the reference lists of the included studies. Based on the full texts, another 4 were excluded. Eventually, 59 studies were included in the review, 32 on basic research and 19 on clinicopathological research. 8 studies fell in both categories. The basic research studies show that MMP-14 plays an important role in ovarian cancer in the processes of proliferation, invasion, angiogenesis and metastasis. In clinocopathological research, MMP-14 expression is found in most tumours with characteristics of poor prognosis but this immunohistochemical MMP-14 determination does not seem to be an independent predictor of prognosis.

CONCLUSIONS

From this systematic review of the literature concerning MMP-14 in ovarian cancer it becomes clear that MMP-14 plays various important roles in the pathophysiology of ovarian cancer. The exact translation of these roles in the pathophysiology to the importance of MMP-14 in clinicopathological research in ovarian cancer and possible therapeutic role of anti-MMP-14 agents needs further elucidation.

The attributes of plakins in cancer and disease: perspectives on ovarian cancer progression, chemoresistance and recurrence

The plakin family of cytoskeletal proteins play an important role in cancer progression yet are under-studied in cancer, especially ovarian cancer. These large cytoskeletal proteins have primary roles in the maintenance of cytoskeletal integrity but are also associated with scaffolds of intermediate filaments and hemidesmosomal adhesion complexes mediating signalling pathways that regulate cellular growth, migration, invasion and differentiation as well as stress response. Abnormalities of plakins, and the closely related spectraplakins, result in diseases of the skin, striated muscle and nervous tissue. Their prevalence in epithelial cells suggests that plakins may play a role in epithelial ovarian cancer progression and recurrence. In this review article, we explore the roles of plakins, particularly plectin, periplakin and envoplakin in disease-states and cancers with emphasis on ovarian cancer. We discuss the potential role the plakin family of proteins play in regulating cancer cell growth, survival, migration, invasion and drug resistance. We highlight potential relationships between plakins, epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs) and discuss how interaction of these processes may affect ovarian cancer progression, chemoresistance and ultimately recurrence. We propose that molecular changes in the expression of plakins leads to the transition of benign ovarian tumours to carcinomas, as well as floating cellular aggregates (commonly known as spheroids) in the ascites microenvironment, which may contribute to the sustenance and progression of the disease. In this review, attempts have been made to understand the crucial changes in plakin expression in relation to progression and recurrence of ovarian cancer.

TIMP-1 is Overexpressed and Secreted by Platinum Resistant Epithelial Ovarian Cancer Cells

Epithelial Ovarian Cancer (EOC) is the most lethal gynecological cancer in developed countries, and the development of new strategies to overcome chemoresistance is an awaited clinical need. Angiogenesis, the development of new blood vessels from pre-existing vasculature, has been validated as a therapeutic target in this tumor type. The aim of this study is to verify if EOC cells with acquired resistance to platinum (PT) treatment display an altered angiogenic potential. Using a proteomic approach, we identified the tissue inhibitor of metalloproteinases 1 (TIMP-1) as the only secreted factor whose expression was up-regulated in PT-resistant TOV-112D and OVSAHO EOC cells used as study models. We report that TIMP-1 acts as a double-edged sword in the EOC microenvironment, directly affecting the response to PT treatment on tumor cells and indirectly altering migration and proliferation of endothelial cells. Interestingly, we found that high TIMP-1 levels in stage III–IV EOC patients associate with decreased overall survival, especially if they were treated with PT or bevacizumab. Taken together, these results pinpoint TIMP-1 as a key molecule involved in the regulation of EOC PT-resistance and progression disclosing the possibility that it could be used as a new biomarker of PT-resistance and/or therapeutic target.

MicroRNA-509-3p inhibits cellular migration, invasion, and proliferation, and sensitizes osteosarcoma to cisplatin

Osteosarcoma (OS) is the most common primary pediatric malignancy of the bone having poor prognosis and long-term survival rates of less than 30% in patients with metastasis. MicroRNA-509 was reported to be downregulated in OS. We and others previously published that miR-509-3p can strongly attenuate cellular migration/invasion and sensitize ovarian cancer to cisplatin. Here, we show that overexpression of miR-509-3p inhibited migration of primary OS cell lines U2OS, HOS, and SaOS2 as well as metastatic derivatives 143B and LM7. miR-509-3p overexpression also inhibited proliferation and invasion of HOS and 143B cells and sensitized cells to cisplatin. Luciferase reporter assays using 3'-UTRs of predicted miR-509-3p targets associated with metastatic phenotypes revealed ARHGAP1 could be one of the downstream effectors of miR-509-3p in HOS. To find the global impact of miR-509-3p overexpression and cisplatin treatment we performed Reverse Phase Protein Analysis (RPPA). AXL, which has been reported to play a critical role in cisplatin resistance and confirmed as direct target of miR-509-3p was downregulated upon miR-509-3p treatment and further down-regulated upon miR-509-3p + cisplatin treatment. We propose that the miR-509-3p/AXL and miR-509-3p/ARHGAP1 axes have the potential to uncover new druggable targets for the treatment of drug resistant metastatic osteosarcoma.

Inhibition of Phosphatidylinositol 3-kinase (PI3K) Signaling Synergistically Potentiates Antitumor Efficacy of Paclitaxel and Overcomes Paclitaxel-Mediated Resistance in Cervical Cancer

Acquired paclitaxel (PTX) resistance limits its effectiveness and results in advanced cancer progression. This review investigated whether the inhibition of phosphatidylinositol 3-kinase (PI3K) signaling overcomes paclitaxel resistance in cervical cancer. It was established paclitaxel-resistant cell lines (PTX-R ME180/PTX-R HeLa) and determined the combination index for paclitaxel and PI3K inhibitors (BYL-719/ LY294002) by tetrazolium dye assay. Flow cytometry was used to detect the cell cycle and apoptosis. Migration and invasion were explored by wound healing and transwell assays. Genes related to multiple pathways were assessed by a western blot. It was found that the PI3K pathway was significantly activated in paclitaxel-resistant HeLa and ME180 cells compared to parental cells. PTX + PI3K inhibitor combined therapy showed a synergistic effect by strengthening paclitaxel-induced S and G2M arrest in PTX-R cell sublines by the inactivation of cyclin A1, cyclin B1, cyclin E, and Cdc2 expression. Moreover, combination therapy significantly enhanced drug sensitivity and apoptosis through the activation of Bax, and cleavage of poly-(ADP-ribose) polymerase compared with paclitaxel alone. In addition, PI3K inhibition also suppressed tumor migration and invasion by targeting β-catenin and matrix metalloproteinase-2/9. The authors suggest that the combination of a PI3K inhibitor with paclitaxel may enhance antitumor activity through a cascade of PI3K signaling events.

Bioactive Compounds from Posidonia oceanica (L.) Delile Impair Malignant Cell Migration through Autophagy Modulation

Posidonia oceanica (L.) Delile is a marine plant with interesting biological properties potentially ascribed to the synergistic combination of bioactive compounds. Our previously described extract, obtained from the leaves of P. oceanica, showed the ability to impair HT1080 cell migration by targeting both expression and activity of gelatinases. Commonly, the lack of knowledge about the mechanism of action of phytocomplexes may be an obstacle regarding their therapeutic use and development. The aim of this study was to gain insight into the molecular signaling through which such bioactive compounds impact on malignant cell migration and gelatinolytic activity. The increase in autophagic vacuoles detected by confocal microscopy suggested an enhancement of autophagy in a time and dose dependent manner. This autophagy activation was further confirmed by monitoring pivotal markers of autophagy signaling as well as by evidencing an increase in IGF-1R accumulation on cell membranes. Taken together, our results confirm that the P. oceanica phytocomplex is a promising reservoir of potent and cell safe molecules able to defend against malignancies and other diseases in which gelatinases play a major role in progression. In conclusion, the attractive properties of this phytocomplex may be of industrial interest in regard to the development of novel health-promoting and pharmacological products for the treatment or prevention of several diseases.

Regulation of ATP utilization during metastatic cell migration by collagen architecture

Cell migration in a three-dimensional matrix requires that cells either remodel the surrounding matrix fibers and/or squeeze between the fibers to move. Matrix degradation, matrix remodeling, and changes in cell shape each require cells to expend energy. While significant research has been performed to understand the cellular and molecular mechanisms guiding metastatic migration, less is known about cellular energy regulation and utilization during three-dimensional cancer cell migration. Here we introduce the use of the genetically encoded fluorescent biomarkers, PercevalHR and pHRed, to quantitatively assess ATP, ADP, and pH levels in MDA-MB-231 metastatic cancer cells as a function of the local collagen microenvironment. We find that the use of the probe is an effective tool for exploring the thermodynamics of cancer cell migration and invasion. Specifically, we find that the ATP:ADP ratio increases in cells in denser matrices, where migration is impaired, and it decreases in cells in aligned collagen matrices, where migration is facilitated. When migration is pharmacologically inhibited, the ATP:ADP ratio decreases. Together, our data indicate that matrix architecture alters cellular energetics and that intracellular ATP:ADP ratio is related to the ability of cancer cells to effectively migrate.

Role of Akt signaling in resistance to DNA-targeted therapy

The Akt signal transduction pathway controls most hallmarks of cancer. Activation of the Akt cascade promotes a malignant phenotype and is also widely implicated in drug resistance. Therefore, the modulation of Akt activity is regarded as an attractive strategy to enhance the efficacy of cancer therapy and irradiation. This pathway consists of phosphatidylinositol 3 kinase (PI3K), mammalian target of rapamycin, and the transforming serine-threonine kinase Akt protein isoforms, also known as protein kinase B. DNA-targeted agents, such as platinum agents, taxanes, and antimetabolites, as well as radiation have had a significant impact on cancer treatment by affecting DNA replication, which is aberrantly activated in malignancies. However, the caveat is that they may also trigger the activation of repairing mechanisms, such as upstream and downstream cascade of Akt survival pathway. Thus, each target can theoretically be inhibited in view of improving the potency of conventional treatment. Akt inhibitors, e.g., MK-2206 and perifosine, or PI3K modulators, e.g., LY294002 and Wortmannin, have shown some promising results in favor of sensitizing the cancer cells to the therapy in vitro and in vivo, which have provided the rationale for incorporation of these novel agents into multimodality treatment of different malignancies. Nevertheless, despite the acceptable safety profile of some of these agents in the clinical studies, with regard to the efficacy, the results are still too preliminary. Hence, we need to wait for the upcoming data from the ongoing trials before utilizing them into the standard care of cancer patients.

Rhus verniciflua Stokes (RVS) and butein induce apoptosis of paclitaxel-resistant SKOV-3/PAX ovarian cancer cells through inhibition of AKT phosphorylation

BACKGROUND

Rhus verniciflua Stokes (RVS) belongs to the Anacardiaceae family and traditionally used for cancer treatment. RVS and butein, a major compound of RVS, were known to induce apoptosis via AKT inhibition in cancer cells. Thus, in this study, we investigated the effect of RVS and its derivative compounds (fisetin, quercetin, butein) on cell death in SKOV-3/PAX cells.

METHODS

The 80 % ethanol extract of RVS and its derivative compounds (fisetin, quercetin, butein) were prepared. The cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) colorimetric assay. Apoptotic cells were detected by staining with propidium iodide (PI) and Annexin V-fluorescein isothiocyanate/7-aminoactinomycin D (Annexin V-FITC/7-AAD). The expression level of intracellular signaling related-proteins in apoptosis and growth were measured by western blot assay.

RESULTS

We found that RVS and butein suppressed the growth of SKOV-3/PAX cells in a dose-dependent manner. We also found that RVS and butein produced the cleavage of caspase-9, -8, -3, and PARP. Similarly, sub-G1 phase and Annexin V-FITC positive cells were increased by RVS and butein. Moreover, RVS and butein significantly reduced AKT phosphorylation in SKOV-3/PAX cells. PI3K inhibitor LY294002 caused PARP cleavage supporting our finding.

CONCLUSION

Our data clearly indicate that RVS and butein induce apoptosis of SKOV-3/PAX cells through inhibition of AKT activation. RVS and butein could be useful compounds for the treatment for paclitaxel resistant-ovarian cancer.

Limited independent prognostic value of MMP-14 and MMP-2 expression in ovarian cancer

BACKGROUND

In cancer, various MMPs play a role in progression and metastasis and their overexpression generally indicates a poor prognosis. MMP-14 is the main activator of MMP-2 and both molecules play a role in normal ovarian follicular development. Earlier reports indicated a prognostic value for both MMP-14 and MMP-2 in ovarian cancer. This study was designed to determine the prognostic value of MMP-14 and MMP-2 expression in ovarian cancer with data on long-term follow-up.

METHODS

Tumor samples of 94 consecutive ovarian cancer patients from one regional laboratory were evaluated. Clinical and survival data were collected and related to known prognostic factors, as well as to the expression of MMP-14 and MMP-2 as determined by semi-quantitative immunohistochemistry.

RESULTS

Epithelial MMP-14 expression correlated with stromal MMP-14 expression (rho = .47, p < .01) and epithelial MMP-2 expression was found to correlate with both MMP-14 epithelial and stromal expression (rho = -.28, p < .01 respectively rho = -.21, p < .05). In univariable analysis of 64 advanced-staged tumours, no MMP parameter was significant for progression-free or overall survival. In multivariable analysis for PFS, stromal MMP-14 expression and epithelial MMP-2 expression remained in the model. For overall survival, no MMP parameter showed significance.

CONCLUSIONS

We confirmed the correlation between epithelial and stromal MMP-14 expression and between epithelial MMP-2 and both epithelial and stromal MMP-14 expression. In this study with long-term follow-up, the independent prognostic value of MMP-14 and MMP-2 expression in ovarian cancer is limited to a role in PFS for stromal MMP-14 expression and epithelial MMP-2 expression.

Anti-metastatic action of FAK inhibitor OXA-11 in combination with VEGFR-2 signaling blockade in pancreatic neuroendocrine tumors

The present study sought to determine the anti-tumor effects of OXA-11, a potent, novel small-molecule amino pyrimidine inhibitor (1.2 pM biochemical IC(50)) of focal adhesion kinase (FAK). In studies of cancer cell lines, OXA-11 inhibited FAK phosphorylation at phospho-tyrosine 397 with a mechanistic IC(50) of 1 nM in TOV21G tumor cells, which translated into functional suppression of proliferation in 3-dimensional culture with an EC(50) of 9 nM. Studies of OXA-11 activity in TOV21G tumor-cell xenografts in mice revealed a pharmacodynamic EC(50) of 1.8 nM, indicative of mechanistic inhibition of pFAK [Y397] in these tumors. OXA-11 inhibited TOV21G tumor growth in a dose-dependent manner and also potentiated effects of cisplatin on tumor cell proliferation and apoptosis in vitro and on tumor growth in mice. Studies of pancreatic neuroendocrine tumors in RIP-Tag2 transgenic mice revealed OXA-11 suppression of pFAK [Y397] and pFAK [Y861] in tumors and liver. OXA-11 given daily from age 14 to 17 weeks reduced tumor vascularity, invasion, and when given together with the anti-VEGFR-2 antibody DC101 reduced the incidence, abundance, and size of liver metastases. Liver micrometastases were found in 100 % of mice treated with vehicle, 84 % of mice treated with OXA-11, and 79 % of mice treated with DC101 (19-24 mice per group). In contrast, liver micrometastases were found in only 52 % of 21 mice treated with OXA-11 plus DC101, and those present were significantly smaller and less numerous. Together, these findings indicate that OXA-11 is a potent and selective inhibitor of FAK phosphorylation in vitro and in vivo. OXA-11 slows tumor growth, potentiates the anti-tumor actions of cisplatin and--when combined with VEGFR-2 blockade--reduces metastasis of pancreatic neuroendocrine tumors in RIP-Tag2 mice.

Minocycline attenuates hypoxia-inducible factor-1α expression correlated with modulation of p53 and AKT/mTOR/p70S6K/4E-BP1 pathway in ovarian cancer: in vitro and in vivo studies

Hypoxia-inducible factor (HIF)-1α is the key cellular survival protein under hypoxia, and is associated with tumor progression and angiogenesis. We have recently shown the inhibitory effects of minocycline on ovarian tumor growth correlated with attenuation of vascular endothelial growth factor (VEGF) and herein report a companion laboratory study to test if these effects were the result of HIF-1α inhibition. In vitro, human ovarian carcinoma cell lines (A2780, OVCAR-3 and SKOV-3) were utilized to examine the effect of minocycline on HIF-1 and its upstream pathway components to elucidate the underlying mechanism of action of minocycline. Mice harboring OVCAR-3 xenografts were treated with minocycline to assess the in vivo efficacy of minocycline in the context of HIF-1. Minocycline negatively regulated HIF-1α protein levels in a concentration-dependent manner and induced its degradation by a mechanism that is independent of prolyl-hydroxylation. The inhibition of HIF-1α was found to be associated with up-regulation of endogenous p53, a tumor suppressor with confirmed role in HIF-1α degradation. Further studies demonstrated that the effect of minocycline was not restricted to proteasomal degradation and that it also caused down-regulation of HIF-1α translation by suppressing the AKT/mTOR/p70S6K/4E-BP1 signaling pathway. Minocycline treatment of mice bearing established ovarian tumors, led to suppression of HIF-1α accompanied by up-regulation of p53 protein levels and inactivation of AKT/mTOR/p70S6K/4E-BP1 pathway. These data reveal the therapeutic potential of minocycline in ovarian cancer as an agent that targets the pro-oncogenic factor HIF-1α through multiple mechanisms.

Wilms' tumour suppressor gene 1 (WT1) is involved in the carcinogenesis of Lung cancer through interaction with PI3K/Akt pathway

Absract

Although studies have shown the oncogene WT1 is overexpressed in lung cancer, there is no data showing the implication of WT1 in lung cancer biology. In the present study, we first demonstrated that isotype C of WT1 was conservely overexpressed in 20 lung cancer patient specimens. Knockdown of WT1 by small interference RNA (siRNA) transfection resulted in a significant inhibition of cell proliferation, induction of cell cycle arrest at G₁ phase, and the expression change of BCL-2 family genes in WT1⁺ A549 cells. Furthermore, we found that DDP treatment could decrease the WT1 mRNA expression level by 5% and 15% at a dose of 1 μg/ml, by 25% and 40% at a dose of 2 μg/ml for 24 and 48 h, respectively. In the mean time, DDP treatment also reduced the PI3K/AKT pathway activity. Further analysis by using siRNA targeting the AKT-1 and the PI3K pathway inhibitor Ly294002 revealed that the AKT-1 siRNA reduced the WT1 expression effectively in A549 cells, and the same result was observed in Ly294002 treated cells, indicating that DDP treatment could down regulate WT1 expression through the PI3K/AKT pathway. Of particular interest, knockdown of WT1 also inhibited the AKT expression effectively, Chip assay further confirmed that WT1 is a transcription factor of AKT-1. We thus concluded that there is a positive feedback loop between WT1 and AKT-1. Taken together, DDP treatment downregulates the WT1 expression through the PI3K/AKT signaling pathway, and there is a feedback between WT1 and AKT-1; WT1 is involved in cellular proliferation in A549 cells, WT1 inhibition in combination with DDP will provide a new light for lung cancer therapy.

LY294002 and Rapamycin promote coxsackievirus-induced cytopathic effect and apoptosis via inhibition of PI3K/AKT/mTOR signaling pathway

Coxsackievirus B3 (CVB3) is a common human pathogen for acute myocarditis, pancreatitis, non-septic meningitis, and encephalitis; it induces a direct cytopathic effect (CPE) and apoptosis on infected cells. The Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT/PKB)/mammalian target of Rapamycin (mTOR) signaling pathway regulates several cellular processes and it is one of the most important pathways in human networks. However, the effect and mechanism of PI3K/AKT/mTOR signaling pathway in CVB3 infected cells are poorly understood. In this study, we demonstrate that inhibition of PI3K/AKT/mTOR signaling pathway increased CVB3-induced CPE and apoptosis in HeLa cells. The activity of downstream targets of PI3K and mTOR is attenuated after CVB3 infection and inhibitors of PI3K and mTOR made their activity to decrease more significantly. We further show that LY294002 and Rapamycin, the inhibitor of PI3K and mTOR respectively, promote CVB3-induced CPE and apoptosis. Taken together, these data illustrate a new and imperative role for PI3K/AKT/mTOR signaling in CVB3 infection in HeLa cells and suggest an useful approach for the therapy of CVB3 infection.

The importance of the PI3K/AKT/MTOR pathway in the progression of ovarian cancer

Ovarian cancer is the fifth most common cause of death due to cancer in women despite being the tenth in incidence. Unfortunately, the five-year survival rate is only 45%, which has not improved much in the past 30 years. Even though the majority of women have successful initial therapy, the low rate of survival is due to the eventual recurrence and succumbing to their disease. With the recent release of the Cancer Genome Atlas for ovarian cancer, it was shown that the PI3K/AKT/mTOR pathway was one of the most frequently mutated or altered pathways in patients’ tumors. Researching how the PI3K/AKT/mTOR pathway affects the progression and tumorigensis of ovarian cancer will hopefully lead to new therapies that will increase survival for women. This review focuses on recent research on the PI3K/AKT/mTOR pathway and its role in the progression and tumorigensis of ovarian cancer.

Pre-Treatment of platinum resistant ovarian cancer cells with an MMP-9/MMP-2 inhibitor prior to cisplatin enhances cytotoxicity as determined by high content screening

Platinum resistance is a major cause of treatment failure in ovarian cancer. We previously identified matrix metalloproteinase 9 (MMP-9) as a potential therapeutic target of chemoresistant disease. A2780cis (cisplatin-resistant) and A2780 (cisplatin-sensitive) ovarian carcinoma cell lines were used. The cytotoxic effect of MMP-9/MMP-2 inhibitor, (2R)-2-[(4-Biphenylsulfonyl) amino]-3 phenylpropionic acid (C21H19NO4S) alone or in combination with cisplatin was determined using high content screening. Protein expression was examined using immunohistochemistry and ELISA. Co-incubation of cisplatin and an MMP-9/MMP-2 inhibitor, (2R)-2-[(4-Biphenylsulfonyl) amino]-3 phenylpropionic acid (C21H19NO4S) resulted in significantly greater cytotoxicity as compared to either treatment alone in a cisplatin resistant MMP-9 overexpressing cell line; A2780cis. In addition, pre-incubating with MMP-9i prior to cisplatin further enhances the cytotoxic effect. No significant difference was observed in MMP-9 protein in tissue but a trend towards increased MMP-9 was observed in recurrent serum. We propose that MMP-9/MMP-2i may be utilized in the treatment of recurrent/chemoresistant ovarian cancers that overexpress MMP-9 mRNA but its role in vivo remains to be evaluated.

Sarcomas induced in discrete subsets of prospectively isolated skeletal muscle cells

Soft-tissue sarcomas are heterogeneous cancers that can present with tissue-specific differentiation markers. To examine the cellular basis for this histopathological variation and to identify sarcoma-relevant molecular pathways, we generated a chimeric mouse model in which sarcoma-associated genetic lesions can be introduced into discrete, muscle-resident myogenic and mesenchymal cell lineages. Expression of Kirsten rat sarcoma viral oncogene [Kras(G12V)] and disruption of cyclin-dependent kinase inhibitor 2A (CDKN2A; p16p19) in prospectively isolated satellite cells gave rise to pleomorphic rhabdomyosarcomas (MyoD-, Myogenin- and Desmin-positive), whereas introduction of the same oncogenetic hits in nonmyogenic progenitors induced pleomorphic sarcomas lacking myogenic features. Transcriptional profiling demonstrated that myogenic and nonmyogenic Kras; p16p19(null) sarcomas recapitulate gene-expression signatures of human rhabdomyosarcomas and identified a cluster of genes that is concordantly up-regulated in both mouse and human sarcomas. This cluster includes genes associated with Ras and mechanistic target of rapamycin (mTOR) signaling, a finding consistent with activation of the Ras and mTOR pathways both in Kras; p16p19(null) sarcomas and in 26-50% of human rhabdomyosarcomas surveyed. Moreover, chemical inhibition of Ras or mTOR signaling arrested the growth of mouse Kras; p16p19(null) sarcomas and of human rhabdomyosarcoma cells in vitro and in vivo. Taken together, these data demonstrate the critical importance of lineage commitment within the tumor cell-of-origin in determining sarcoma histotype and introduce an experimental platform for rapid dissection of sarcoma-relevant cellular and molecular events.

Global phosphoproteome profiling reveals unanticipated networks responsive to cisplatin treatment of embryonic stem cells

Cellular responses to DNA-damaging agents involve the activation of various DNA damage signaling and transduction pathways. Using quantitative and high-resolution tandem mass spectrometry, we determined global changes in protein level and phosphorylation site profiles following treatment of SILAC (stable isotope labeling by amino acids in cell culture)-labeled murine embryonic stem cells with the anticancer drug cisplatin. Network and pathway analyses indicated that processes related to the DNA damage response and cytoskeleton organization were significantly affected. Although the ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3-related) consensus sequence (S/T-Q motif) was significantly overrepresented among hyperphosphorylated peptides, about half of the >2-fold-upregulated phosphorylation sites based on the consensus sequence were not direct substrates of ATM and ATR. Eleven protein kinases mainly belonging to the mitogen-activated protein kinase (MAPK) family were identified as being regulated in their kinase domain activation loop. The biological importance of three of these kinases (cyclin-dependent kinase 7 [CDK7], Plk1, and KPCD1) in the protection against cisplatin-induced cytotoxicity was demonstrated by small interfering RNA (siRNA)-mediated knockdown. Our results indicate that the cellular response to cisplatin involves a variety of kinases and phosphatases not only acting in the nucleus but also regulating cytoplasmic targets, resulting in extensive cytoskeletal rearrangements. Integration of transcriptomic and proteomic data revealed a poor correlation between changes in the relative levels of transcripts and their corresponding proteins, but a large overlap in affected pathways at the levels of mRNA, protein, and phosphoprotein. This study provides an integrated view of pathways activated by genotoxic stress and deciphers kinases that play a pivotal role in regulating cellular processes other than the DNA damage response.

Adhesion molecule periplakin is involved in cellular movement and attachment in pharyngeal squamous cancer cells

Background

We previously reported that periplakin (PPL) is downregulated in human esophageal cancer tissues compared to the adjacent non-cancer epithelium. Thus PPL could be a useful marker for detection of early esophageal cancer and evaluation of tumor progression, but largely remains unknown in this field. To investigate PPL involvement in carcinogenesis, tumor progression, cellular movement or attachment activity, siRNAs against PPL were transfected into pharyngeal squamous cancer cell lines and their effects on cellular behaviours were examined.

Results

PPL knockdown appeared to decrease tumor cell growth together with G2/M phase accumulation in cells attached to a culture dish. However, the extent of cell growth suppression, evaluated by the number of cells attached to the culture dish, was too distinctive to be explained only by cell cycle delay. Importantly, PPL knockdown suppressed cellular movement and attachment to the culture dish accompanied by decreased pAktSer473 phosphorylation. Additionally, LY294002, a PI3K inhibitor that dephosphorylates pAktSer473, significantly suppressed D562 cell migration. Thus PPL potentially engages in cellular movement al least partly via the PI3K/Akt axis.

Conclusions

PPL knockdown is related to reduced cellular movement and attachment activity in association with PI3K/Akt axis suppression, rather than malignant progression in pharyngeal cancer cells.

Dual targeting of phosphoinositide 3-kinase and mammalian target of rapamycin using NVP-BEZ235 as a novel therapeutic approach in human ovarian carcinoma

PURPOSE

This study evaluates the effect of dual PI3K and mTOR inhibition using NVP-BEZ235 in preclinical models of ovarian cancer as a potential novel therapeutic strategy.

EXPERIMENTAL DESIGN

Inhibition of PI3K/Akt/mTOR signaling by NVP-BEZ235 was demonstrated by immunoblotting. The effect on cell proliferation was assessed in 18 ovarian cancer cell lines, including four pairs of syngeneic cisplatin-sensitive and cisplatin-resistant cell lines. The in vivo effects of NVP-BEZ235 on established tumor growth were evaluated using an immunocompetent, transgenic murine ovarian cancer model (LSL-K-ras(G12D/+)Pten(loxP/loxP)).

RESULTS

NVP-BEZ235 decreased cell proliferation in all ovarian cancer cell lines assayed and sensitized cisplatin-resistant cells to the cytotoxic effects of cisplatin. Cell lines with PI3K-activating mutations or Pten deletions were significantly more sensitive to the effect of NVP-BEZ235 than cell lines without these mutations (P < 0.05). A statistically significant correlation was found between relative levels of p4E-BP1 and the IC(50) for NVP-BEZ235. In LSL-K-ras(G12D/+)Pten(loxP/loxP) mice with established intraperitoneal tumor disease, oral administration of NVP-BEZ235 decreased pAkt, p4E-BP1 and Ki67 in tumor tissue, and resulted in significantly longer survival compared to control animals (P < 0.05). NVP-BEZ235 also induced cell cycle arrest, caspase 3 activity, and reduced cell migration.

CONCLUSIONS

Targeting PI3K and mTOR simultaneously using NVP-BEZ235 effectively inhibits ovarian cancer cell growth even in the presence of platinum resistance and prolongs survival of mice with intra-abdominal ovarian tumor disease. We propose that dual PI3K and mTOR inhibition using NVP-BEZ235 may be an effective novel therapeutic approach in patients with ovarian cancer.

LY294002 potentiates the anti-cancer effect of oxaliplatin for gastric cancer via death receptor pathway

AIM: To examine the effects of combined treatment of oxaliplatin and phosphatidylinositol 3’-kinase inhibitor, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) for gastric cancer.

METHODS: Cell viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptotic cells were detected by flow cytometric analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. Western blotting and immuno-precipitation were used to examine protein expression and recruitment, respectively. Nuclear factor κB (NFκB) binding activities were investigated using electrophoretic mobility shift assay. Nude mice were used to investigate tumor growth.

RESULTS: Treatment with combined oxaliplatin and LY294002 resulted in increased cell growth inhibition and cell apoptosis in vitro, and increased tumor growth inhibition and cell death in the tumor mass in vivo. In MKN45 and AGS cells, oxaliplatin treatment promoted both protein kinase B (Akt) and NFκB activation, while pretreatment with LY294002 significantly attenuated oxaliplatin-induced Akt activity and NFκB binding. LY294002 promoted oxaliplatin-induced Fas ligand (FasL) expression, Fas-associated death domain protein recruitment, caspase-8, Bid, and caspase-3 activation, and the short form of cellular caspase-8/FLICE-inhibitory protein (c-FLIP_S) inhibition. In vivo, LY294002 inhibited oxaliplatin-induced activation of Akt and NFκB, and increased oxaliplatin-induced expression of FasL, inhibition of c-FLIP_S, and activation of caspase-8, Bid, and caspase-3.

CONCLUSION: Combination of oxaliplatin and LY294002 was therapeutically promising for gastric cancer treatment. The enhanced sensitivity of the combined treatment was associated with the activation of the death receptor pathway.