Browsing by Subject "Metastasis"

Now showing 1 - 13 of 13

Open Access
Biosystems engineering of prokaryotes with tumor-killing capacities
(Bentham Science Publishers Ltd., 2016) Kalyoncu, E.; Olmez, T. T.; Ozkan, A. D.; Sarioglu, O. F.
Certain bacteria selectively attack tumor tissues and trigger tumor shrinkage by producing toxins and modulating the local immune system, but their clinical utility is limited because of the dangers posed by systemic infection. Genetic engineering can be used to minimize the risks associated with tumor-targeting pathogens, as well as to increase their efficiency in killing tumor cells. Advances in genetic circuit design have led to the development of bacterial strains with enhanced tumor-targeting capacities and the ability to secrete therapeutics, cytotoxic proteins and prodrug-cleaving enzymes, which allows their safe and effective use for cancer treatment. The present review details the recent advances in the design and application of these modified bacterial strains.
Open Access
HER2 and proliferation of wound-induced breast carcinoma
(The Lancet Publishing, 2003-11-01) Tez, M.; Göçmen, E.; Özçelik, T.
Open Access
Identification of the roles played by IKKε in hepatocellular and colorectal carcinogenesis
(2018-07) Kahya, Uğur
Hepatocellular carcinomas (HCC) and colorectal carcinomas (CRC) are among the most common cancers worldwide with high mortality rates. While HCC affecting mostly underdeveloped countries, CRC is a disease that mainly occur in more developed countries. As is known, CRC is the third most common cancer and the surgical removal of tumors upon early diagnosis is still the best tool in our hands, developing better strategies to cure patients with an advanced CRC has utmost importance. Furthermore, survival rates of HCC patients are very low as a result of poor prognosis and the most efficient therapy for HCC is organ transplantation. Sorafenib, a multikinase inhibitor, is the most effective chemotherapeutic agent in use for HCC leading drug resistance in HCC cells. Thus, alternative strategies should be developed to extend disease-free survival and to treat this cancer. One of the major risk factor for cancer is chronic inflammation and HCC is a good example of inflammation related cancer due to the fact that 90% of HCC cases are stem from inflammation and hepatic injury. As a result of unresolved chronic inflammation, sequential development of HCC occurs from fibrosis and cirrhosis. Moreover, tumor-associated inflammation can encourage tumor development in the gut, indicating central role for inflammation in the development of both sporadic CRC and CAC. In this thesis, our aim was to understand the roles played by IKKε in hepatocellular and colorectal carcinogenesis. Our preliminary bioinformatics analysis with publicly available data has shown high amplification of IKKε in HCC patients in silico. Also, we showed that IKKε plays important roles in HCC cell proliferation and viability. Specifically, upon IKKε depletion, we observed reductions in HCC cell proliferation both in vivo and in vitro. Furthermore, increase epithelial markers upon IKKε loss was suggesting reversed EMT process in HEP3B cells. Consequently, IKKε could be a valuable prognostic biomarker and targeting IKKε may be a potential therapeutic strategy against HCC tumors. On the other hand, in CRC, we demonstrated that IKKε depletion conferred a growth advantage to IKKε depleted DLD1 and SW480 cells and resulted in an increased proliferation in vivo and in vitro, and induced formation of partial-EMT like features in DLD1 cells. Therefore, IKKε complementation may be a valuable potential therapeutic strategy against CRC tumors.
Open Access
IKKs and tumor cell plasticity
(Wiley-Blackwell Publishing Ltd., 2018) Göktuna, Serkan İsmail; Diamanti, M. A.; Chau, T. L.
Nuclear factor κB (NF-κB) transcription factors are the central hubs of signaling pathways connecting proinflammatory signals to cell survival, proliferation and cytokine production. In cancers, NF-κB signaling influences many aspects of tumor development, from initiation to metastasis. These functions are mediated by tumor-induced plasticity that allows tumor cells to adapt and survive in changing conditions within the tumor microenvironment. Tumor cell plasticity is shaped by the inflammatory microenvironment in tumors. This review focuses on inhibitor of NF-κB kinases, the direct upstream elements of NF-κB regulation, specifically on their conventional and non-conventional functions in animal models of tumorigenesis from the recent literature.
Open Access
Mechanistic pathways of malignancy in breast cancer stem cells
(Frontiers Media S.A., 2020-04-30) Yousefnia, S.; Forootan, F. S.; Forootan, S. S.; Esfahani, M. H. N.; Güre, Ali Osmay
Breast cancer stem cells (BCSCs) are the minor population of breast cancer (BC) cells that exhibit several phenotypes such as migration, invasion, self-renewal, and chemotherapy as well as radiotherapy resistance. Recently, BCSCs have been more considerable due to their capacity for recurrence of tumors after treatment. Recognition of signaling pathways and molecular mechanisms involved in stemness phenotypes of BCSCs could be effective for discovering novel treatment strategies to target BCSCs. This review introduces BCSC markers, their roles in stemness phenotypes, and the dysregulated signaling pathways involved in BCSCs such as mitogen-activated protein (MAP) kinase, PI3K/Akt/nuclear factor kappa B (NFκB), TGF-β, hedgehog (Hh), Notch, Wnt/β-catenin, and Hippo pathway. In addition, this review presents recently discovered molecular mechanisms implicated in chemotherapy and radiotherapy resistance, migration, metastasis, and angiogenesis of BCSCs. Finally, we reviewed the role of microRNAs (miRNAs) in BCSCs as well as several other therapeutic strategies such as herbal medicine, biological agents, anti-inflammatory drugs, monoclonal antibodies, nanoparticles, and microRNAs, which have been more considerable in the last decades.
Open Access
Metastasis suppressor genes and proteins in non-melanoma skin cancers
(2014-09) Bozdoğan, Önder
Skin cancers are the most common cancer in human population. They are practically divided into two major group; melanoma and non-melanoma skin cancer (NMSC). NMSC often refers to two common neoplasms; cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma (BCC). BCCs are slow growing, malignant, significantly invasive but rarely metastasizing carcinomas. cSCCs are the malignant tumor of keratinocytes with significant squamous differentiation. In contrast to BCCs, SCCs have significant metastatic capacity. Metastasis is a complex multistep process and strictly positively or negatively controlled by tens of genes or proteins. Besides supporting genes, a group of gene, called metastasis suppressor genes (MSG), slow or inhibit metastasis without significantly affecting tumorigenicity. The aim of this study was to find out distribution and importance of the seven selected metastasis suppressor gene/proteins including NM23-H1, NDRG1, Ecadherin, RHOGDI2 (ARHGDIB), CD82/KAI1, MKK4, and AKAP12 in NMSC. Ninety six BCCs, 32 cSCCs, 6 in-situ SCCs, two cell lines (HaCaT, A-431) were included for immunohistochemistry study. Eleven BCCs, 8 normal skin adjacent to the BCCs, 3 normal skin frozen tissue, and, two cell lines were inserted for qRT-PCR studies. Promoter methylations of CD82/KAI1 and MKK4 genes were analyzed in 7 tumors and 5 normal tissue samples by bisulfite sequencing method. In immunohistochemistry study, NM23-H1 was protected in NMSC. Similarly, relatively preserved cytoplasmic expressions of NDRG1 were also detected. AKAP12 and RHOGDI2 were decreased in both tumor groups. However, CD82/KAI1 downregulation was only detected in BCCs. E-Cadherin was relatively protected in BCCs but significant lost was seen in cSCCs. Cytoplasmic positivity of MKK4 was more pronounced in cSCC when compared to BCCs. Immunohistochemical study of cell lines showed similar finding as in seen cSCC. In qRT-PCR study, we found significant upregulation of NM23-H1 (1.4 fold; p=0.032) and downregulation of AKAP12 (-1.2 fold; p=0.006) when BCC was compared to normal skin. NDRG1 showed significantly higher levels (2.2 fold, p=0.001) in BCC when compared to the skin adjacent to the BCC. MKK4 (-2.1-fold, P=0.001), ARHGDIB (RHOGDI2) (-4.7-fold, P=0.001), CD82/KAI1 (-2.4-fold, P=0.001) and AKAP12 (-9.7-fold, P=0.001) were downregulated but NDRG1 (34.4-fold, p=0.001) was upregulated in A-431 cell line when compared to HaCaT. CD82/KAI and MKK4 promoters were heavily unmethylated in BCCs and normal skin. In conclusion, we have demonstrated differential expression patterns for the seven MSPs in NMSCs. In SCCs, the MSG expression signature is similar but not identical to BCCs. The preserved levels of NM23-H1 and NDRG1 may contribute to the nonmetastatic features of NMSC.
Open Access
MicroRNA expression patterns in canine mammary cancer show significant differences between metastatic and non-metastatic tumours
(BioMed Central Ltd., 2017) Bulkowska, M.; Rybicka, A.; Senses, K. M.; Ulewicz, K.; Witt, K.; Szymanska, J.; Taciak, B.; Klopfleisch, R.; Hellmén, E.; Dolka, I.; Gure, A. O.; Mucha, J.; Mikow, M.; Gizinski, S.; Krol, M.
Background: MicroRNAs may act as oncogenes or tumour suppressor genes, which make these small molecules potential diagnostic/prognostic factors and targets for anticancer therapies. Several common oncogenic microRNAs have been found for canine mammary cancer and human breast cancer. On account of this, large-scale profiling of microRNA expression in canine mammary cancer seems to be important for both dogs and humans. Methods: Expression profiles of 317 microRNAs in 146 canine mammary tumours of different histological type, malignancy grade and clinical history (presence/absence of metastases) and in 25 control samples were evaluated. The profiling was performed using microarrays. Significance Analysis of Microarrays test was applied in the analysis of microarray data (both unsupervised and supervised data analyses were performed). Validation of the obtained results was performed using real-time qPCR. Subsequently, predicted targets for the microRNAs were searched for in miRBase. Results: Results of the unsupervised analysis indicate that the primary factor separating the samples is the metastasis status. Predicted targets for microRNAs differentially expressed in the metastatic vs. non-metastatic group are mostly engaged in cell cycle regulation, cell differentiation and DNA-damage repair. On the other hand, the supervised analysis reveals clusters of differentially expressed microRNAs unique for the tumour type, malignancy grade and metastasis factor. Conclusions: The most significant difference in microRNA expression was observed between the metastatic and non-metastatic group, which suggests a more important role of microRNAs in the metastasis process than in the malignant transformation. Moreover, the differentially expressed microRNAs constitute potential metastasis markers. However, validation of cfa-miR-144, cfa-miR-32 and cfa-miR-374a levels in blood samples did not follow changes observed in the non-metastatic and metastatic tumours.
Open Access
MicroRNas: master regulators of drug resistance, stemness and metastasis
(Springer Berlin Heidelberg, 2014-04) Raza, U.; Zhang, J. D.; Şahin, Ö.
MicroRNAs (miRNAs) are 20-22 nucleotides long small non-coding RNAs that regulate gene expression post-transcriptionally. Last decade has witnessed emerging evidences of active roles of miRNAs in tumor development, progression, metastasis, and drug resistance. Many factors contribute to their dysregulation in cancer, such as chromosomal aberrations, differential methylation of their own or host genes' promoters and alterations in miRNA biogenesis pathways. miRNAs have been shown to act as tumor suppressors or oncogenes depending on the targets they regulate and the tissue where they are expressed. Because miRNAs can regulate dozens of genes simultaneously and they can function as tumor suppressors or oncogenes, they have been proposed as promising targets for cancer therapy. In this review, we focus on the role of miRNAs in driving drug resistance and metastasis which are associated with stem cell properties of cancer cells. Furthermore, we discuss systems biology approaches to combine experimental and computational methods to study effects of miRNAs on gene or protein networks regulating these processes. Finally, we describe methods to target oncogenic or replace tumor suppressor miRNAs and current delivery strategies to sensitize refractory cells and to prevent metastasis. A holistic understanding of miRNAs' functions in drug resistance and metastasis, which are major causes of cancer-related deaths, and the development of novel strategies to target them efficiently will pave the way towards better translation of miRNAs into clinics and management of cancer therapy. © 2014 Springer-Verlag Berlin Heidelberg.
Open Access
The miR-644a/CTBP1/p53 axis suppresses drug resistance by simultaneous inhibition of cell survival and epithelialmesenchymal transition in breast cancer
(Impact Journals LLC, 2016) Raza, U.; Saatci, O.; Uhlmann, S.; Ansari, S. A.; Eyüpoglu, E.; Yurdusev, E.; Mutlu, M.; Ersan, P. G.; Altundağ, M. K.; Zhang, J. D.; Dogan, H. T.; Güler, G.; Şahin, Ö.
Tumor cells develop drug resistance which leads to recurrence and distant metastasis. MicroRNAs are key regulators of tumor pathogenesis; however, little is known whether they can sensitize cells and block metastasis simultaneously. Here, we report miR-644a as a novel inhibitor of both cell survival and EMT whereby acting as pleiotropic therapy-sensitizer in breast cancer. We showed that both miR-644a expression and its gene signature are associated with tumor progression and distant metastasis-free survival. Mechanistically, miR-644a directly targets the transcriptional co-repressor C-Terminal Binding Protein 1 (CTBP1) whose knock-outs by the CRISPRCas9 system inhibit tumor growth, metastasis, and drug resistance, mimicking the phenotypes induced by miR-644a. Furthermore, downregulation of CTBP1 by miR-644a upregulates wild type- or mutant-p53 which acts as a 'molecular switch' between G1-arrest and apoptosis by inducing cyclin-dependent kinase inhibitor 1 (p21, CDKN1A, CIP1) or pro-apoptotic phorbol-12-myristate-13-acetate-induced protein 1 (Noxa, PMAIP1), respectively. Interestingly, an increase in mutant-p53 by either overexpression of miR-644a or downregulation of CTBP1 was enough to shift this balance in favor of apoptosis through upregulation of Noxa. Notably, p53- mutant patients, but not p53-wild type ones, with high CTBP1 have a shorter survival suggesting that CTBP1 could be a potential prognostic factor for breast cancer patients with p53 mutations. Overall, re-activation of the miR-644a/CTBP1/p53 axis may represent a new strategy for overcoming both therapy resistance and metastasis.
Open Access
Patrolling monocytes control tumor metastasis to the lung
(American Association for the Advancement of Science, 2015) Hanna, R. N.; Cekic, C.; Sag, D.; Tacke, R.; Thomas, G. D.; Nowyhed, H.; Herrley, E.; Rasquinha, N.; McArdle, S.; Wu, R.; Peluso, E.; Metzger, D.; Ichinose, H.; Shaked, I.; Chodaczek, G.; Biswas, S. K.; Hedrick, C. C.
The immune system plays an important role in regulating tumor growth and metastasis. Classical monocytes promote tumorigenesis and cancer metastasis, but how nonclassical "patrolling" monocytes (PMo) interact with tumors is unknown. Here we show that PMo are enriched in the microvasculature of the lung and reduce tumor metastasis to lung in multiple mouse metastatic tumor models. Nr4a1-deficient mice, which specifically lack PMo, showed increased lung metastasis in vivo. Transfer of Nr4a1-proficient PMo into Nr4a1-deficient mice prevented tumor invasion in the lung. PMo established early interactions with metastasizing tumor cells, scavenged tumor material from the lung vasculature, and promoted natural killer cell recruitment and activation. Thus, PMo contribute to cancer immunosurveillance and may be targets for cancer immunotherapy.
Open Access
Phosphoproteomic analysis of class IA P110β isoform-specific signal transducers upon PI3K pathway activation
(2023-08) Daloğlu, Beril
PI3K pathway activation is a common event observed in various human cancers. As it regulates cell proliferation, migration and metabolism, it has been widely targeted for anticancer therapies and alteration of drug resistance. Studies focusing on PI3K Class IA isoform-specific inhibition has become critical to achieve alternative targeted treatment methods. Although previous findings show that Class IA isoforms differ in their routes of activation, the downstream targets specific to the isoforms have not been fully profiled yet. This study focuses on the phosphoproteomic analysis of p110 isoform-specific downstream molecules upon PI3K pathway activation. We have created a doxycycline-inducible system in Mouse Embryonic Fibroblasts (MEFs) to express wildtype PIK3CB gene encoding p110β or its catalytic and helical domain over-activating mutants, E1051K and N553S. By immunoblotting, the changes in downstream phosphorylation events were analyzed for MEF p110β mutants or for MEF p110β WT cells upon mitogenic PI3K stimulation. These results were collaborated with the comparative phosphoproteomic data obtained from LC-MS/MS Mass Spectrometry analysis. Our findings show that upon short-term stimulation of the PI3K pathway, proteins associated with transcriptional regulation, cytoskeletal rearrangement, cellular signalling, migration and metabolism are differentially phosphorylated. After longer stimulations on the other hand, proteins involved in cell cycle progression, phosphatase activity, nucleocytoplasmic transport and RNA metabolism become more prominent in the comparative phosphoproteome. Similar to early response proteins in β WT cells, the phosphoproteome of β E1051K cells were associated with cytoskeletal rearrangement and cellular migration. Aligning with the morphological changes observed, proteins involved in anatomical structure regulation were found. Additionally, some tumour suppressors and oncogene proteins were found among the differentially regulated phosphoproteins. On the other hand, the phosphoproteome of β N553S cells were enriched for functions of RNA metabolism, nuclear import and apoptotic regulation. Proteins involved in structural organization and microtubule assembly were also observed. 37 kDa Akt substrate Poly(rC) Binding Protein 1 (Pcbp1) was found as a common differentially phosphorylated protein in the phosphoproteomes of mutant and WT p110β expressing cells. It is an RNA-binding protein associated with metastasis and EMT, and has a critical role in gene expression by coordinating RNA stability and processing. As our results have shown that p110β isoform has a major role in cytoskeletal reorganization, cell migration and transcriptional regulation, studying the regulation of p110β-Pcbp1 axis can pave the way to understand the mechanisms of increased tumour progression in p110β-dependent cells.
Open Access
Prediction of prognosis and chemosensitivity in breast cancer
(2020-09) Akbar, Muhammad Waqas
Breast cancer (BC) is responsible for the highest mortality and morbidity out of all the cancers in women which is primarily due to both inter and intra-tumoral molecular heterogeneity. This heterogeneity arises from stemness, epithelial to mesenchymal transition and the type of treatment given to patients. These three biological processes are highly related with each other. Traditional therapy when given to breast cancer patients generally results in the transition of epithelial cells to mesenchymal phenotype. Because treatment targets primarily non-stem cells, it can leave stem cells alive which can later result in a relapse of cancer. In this study we aimed to identify such markers that could classify breast cancer patients into stem/mesenchymal or non-stem/epithelial like phenotypes, to determine how generalized the above stated hypotheses are. We developed a gene list of 15 genes we term as CSC/non-CSC gene list (CNCL) which classifies tumors into stemness and/or EMT based phenotypes and can also classify tumor cells based on their relative sensitivity to treatment with traditional therapeutics such as paclitaxel and doxorubicin. When classified into stem/mesenchymal (CS/M) and non-stem/epithelial (NS/E) phenotypes, we showed that Lapatinib and Midostaurin have a specific growth inhibitory effects on NS/E cells, and CS/M cells, respectively. Surprisingly the CNCL showed prognostic significance only for patients who were treated with paclitaxel in neoadjuvant setting, while it could not prognosticate most other BC cohorts. We argue that this is due to the dynamic plasticity of these tumors, as studied within the third aim of this thesis. Secondly, we aimed to identify chemotherapy biomarkers for paclitaxel, cisplatin and doxorubicin to stratify patients in groups that will or will not benefit from these drugs. Using biomarkers, we selected for this purpose, we performed linear regression analysis using breast cancer cell lines to generate cytotoxicity prediction models which can predict IC50 values for these drugs, based on the expression of two genes in each model. Two models were selected for doxorubicin and cisplatin, and three models were selected for paclitaxel. All models were validated both in silico and in vitro. Thirdly, we aimed to evaluate breast cancer plasticity that occurs upon treatment or when a tumor metastasizes. We noted that some breast tumors not only switch their clinical subtype but also change their molecular subtype upon treatment or metastasis. As breast cancer patient treatment in the routine practice is routed based on breast cancer subtype, it is very important to identify the subtype switches which can be critical for changes in treatment decisions. Additionally, we also identified metastatic biomarkers using large number of cohorts. Lastly, as CNCL genes did not show any prognostic importance in terms of both overall survival and metastasis free survival, we checked if the same is true for melanoma. We used Melanin A (MLANA) and Inhibin (INHBA) genes as the markers for invasive/proliferative, stem/non-stem and mesenchymal/epithelial phenotypes. High INHBA expression, which is epithelial, proliferative and non-stem phenotype biomarker, was associated with poor survival and high MLANA expression, which is mesenchymal, invasive and stem phenotype marker, was associated with good prognosis in melanoma patients. Therefore, these findings in melanoma supported our results in breast cancer.
Open Access
Systems-level analysis reveals multiple modulators of epithelial-mesenchymal transition and identifies DNAJB4 and CD81 as novel metastasis inducers in breast cancer
(American Society for Biochemistry and Molecular Biology, 2019) Üretmen-Kagıalı, Z. C.; Sanal, E.; Karayel, Ö.; Polat, A. N.; Saatci, Ö.; Ersan, Pelin Gülizar; Trappe, K.; Renard, B. Y.; Önder, T. T.; Tunçbağ, N.; Şahin, Özgür; Özlü, N.
Epithelial-mesenchymal transition (EMT) is driven by complex signaling events that induce dramatic biochemical and morphological changes whereby epithelial cells are converted into cancer cells. However, the underlying molecular mechanisms remain elusive. Here, we used mass spectrometry based quantitative proteomics approach to systematically analyze the post-translational biochemical changes that drive differentiation of human mammary epithelial (HMLE) cells into mesenchymal. We identified 314 proteins out of more than 6,000 unique proteins and 871 phosphopeptides out of more than 7,000 unique phosphopeptides as differentially regulated. We found that phosphoproteome is more unstable and prone to changes during EMT compared with the proteome and multiple alterations at proteome level are not thoroughly represented by transcriptional data highlighting the necessity of proteome level analysis. We discovered cell state specific signaling pathways, such as Hippo, sphingolipid signaling, and unfolded protein response (UPR) by modeling the networks of regulated proteins and potential kinase-substrate groups. We identified two novel factors for EMT whose expression increased on EMT induction: DnaJ heat shock protein family (Hsp40) member B4 (DNAJB4) and cluster of differentiation 81 (CD81). Suppression of DNAJB4 or CD81 in mesenchymal breast cancer cells resulted in decreased cell migration in vitro and led to reduced primary tumor growth, extravasation, and lung metastasis in vivo. Overall, we performed the global proteomic and phosphoproteomic analyses of EMT, identified and validated new mRNA and/or protein level modulators of EMT. This work also provides a unique platform and resource for future studies focusing on metastasis and drug resistance.