β1 and β3 integrins in breast, prostate and pancreatic cancer: A novel implication

Molecular biomarkers in prostate cancer tumorigenesis and clinical relevance

Prostate cancer (PCa) is the second most frequent type of cancer in men and assessing circulating tumor cells (CTCs) by liquid biopsy is a promising tool to help in cancer early detection, staging, risk of recurrence evaluation, treatment prediction and monitoring. Blood-based liquid biopsy approaches enable the enrichment, detection and characterization of CTCs by biomarker analysis. Hence, comprehending the molecular markers, their role on each stage of cancer development and progression is essential to provide information that can help in future implementation of these biomarkers in clinical assistance. In this review, we studied the molecular markers most associated with PCa CTCs to better understand their function on tumorigenesis and metastatic cascade, the methodologies utilized to analyze these biomarkers and their clinical significance, in order to summarize the available information to guide researchers in their investigations, new hypothesis formulation and target choice for the development of new diagnostic and treatment tools.

The role of thrombomodulin in modulating ITGB3 expression and its implications for triple-negative breast cancer progression

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer (BC) compared to other BC subtypes in clinical settings. Currently, there are no effective therapeutic strategies for TNBC treatment. Therefore, there is an urgent need to identify suitable biomarkers or therapeutic targets for TNBC patients. Thrombomodulin (TM) plays a role in cancer progression and metastasis in many different cancers. However, the role of TM in TNBC is not yet fully understood. First, silenced-TM in MDA-MB-231 cells caused an increase in proliferative and metastatic activity. In contrast, overexpression of TM in Hs578T cells caused a reduction in proliferation, invasion, and migration rate. Using RNA-seq analysis, we found that Integrin beta 3 (ITGB3) expression may be a downstream target of TM. Furthermore, we found an increase in ITGB3 levels in TM-KD cells by QPCR and western blot analysis but a decrease in ITGB3 levels in TM-overexpressing cells. We found phospho-smad2/3 levels were increased in TM-KD cells but decreased in TM-overexpressing cells. This implies that TM negatively regulates ITGB3 levels through the activation of the smad2/3 pathway. Silencing ITGB3 in TM-KD cells caused a decrease in proliferation and migration. Finally, we found that higher ITGB3 levels were correlated with poor overall survival and relapse-free survival in patients with TNBC. Our results indicated a novel regulatory relationship between TM and ITGB3 in TNBC.

Transcriptional induction of NF-κB-inducing kinase by E2F4/5 facilitates collective invasion of GBM cells

The prognosis of high-grade gliomas, such as glioblastoma multiforme (GBM), is extremely poor due to the highly invasive nature of these aggressive cancers. Previous work has demonstrated that TNF-weak like factor (TWEAK) induction of the noncanonical NF-κB pathway promotes the invasiveness of GBM cells in an NF-κB-inducing kinase (NIK)-dependent manner. While NIK activity is predominantly regulated at the posttranslational level, we show here that NIK (MAP3K14) is upregulated at the transcriptional level in invading cell populations, with the highest NIK expression observed in the most invasive cells. GBM cells with high induction of NIK gene expression demonstrate characteristics of collective invasion, facilitating invasion of neighboring cells. Furthermore, we demonstrate that the E2F transcription factors E2F4 and E2F5 directly regulate NIK transcription and are required to promote GBM cell invasion in response to TWEAK. Overall, our findings demonstrate that transcriptional induction of NIK facilitates collective cell migration and invasion, thereby promoting GBM pathogenesis.

Genetically engineered E. coli invade epithelial cells and transfer their genetic cargo into the cells: an approach to a gene delivery system

PURPOSE

Despite advances in gene therapy, the lack of safe and efficient gene delivery systems limited the clinical effectiveness of gene therapy. Due to the inherent potential of bacteria, they can be considered as a good option for the gene transfer system. This study aimed to create a genetically engineered bacterium capable of entering epithelial cells and transferring its genetic cargo to the cell's cytoplasm, eventually expressing the gene of interest in the cell.

METHODS

The invasin (inv) gene from Yersinia pseudotuberculosis and the listeriolysin (hlyA) gene from Listeria monocytogenes were isolated by PCR assay and inserted into a pACYCDuet-1 vector. The recombinant plasmid was then transformed into E. coli strain BL21. Subsequently, pEGFP-C1 plasmids containing a CMV promoter were transformed into the engineered bacteria. Finally, the engineered bacteria containing the reporter genes were incubated with the HeLa and LNCaP cell lines. Fluorescence microscopy, flow cytometry, and TEM were used to monitor bacterial entry into the cells and gene expression. We used native E. coli strain BL21 as a control.

RESULTS

A fluorescence microscope showed that, in contrast to the control group, the manipulated E. coli were able to penetrate the cells and transport the plasmid pEGFP-C1 to the target cells. Flow cytometry also showed fluorescence intensity of 54.7% in HeLa cells and 71% in LNCaP cells, respectively. In addition, electron micrographs revealed the presence of bacteria in the cell endosomes and in the cytoplasm of the cells.

CONCLUSION

This study shows that genetically engineered E. coli can enter cells, transport cargo into cells, and induce gene expression in the target cell. In addition, flow cytometry shows that the gene transfer efficiency was sufficient for protein expression.

Engineered Biosensors for Diagnosing Multidrug Resistance in Microbial and Malignant Cells

To curtail pathogens or tumors, antimicrobial or antineoplastic drugs have been developed. These drugs target microbial/cancer growth and survival, thereby improving the host's health. In attempts to evade the detrimental effects of such drugs, these cells have evolved several mechanisms over time. Some variants of the cells have developed resistances against multiple drugs or antimicrobial agents. Such microorganisms or cancer cells are said to exhibit multidrug resistance (MDR). The drug resistance status of a cell can be determined by analyzing several genotypic and phenotypic changes, which are brought about by significant physiological and biochemical alterations. Owing to their resilient nature, treatment and management of MDR cases in clinics is arduous and requires a meticulous approach. Currently, techniques such as plating and culturing, biopsy, gene sequencing, and magnetic resonance imaging are prevalent in clinical practices for determining drug resistance status. However, the major drawbacks of using these methods lie in their time-consuming nature and the problem of translating them into point-of-care or mass-detection tools. To overcome the shortcomings of conventional techniques, biosensors with a low detection limit have been engineered to provide quick and reliable results conveniently. These devices are highly versatile in terms of analyte range and quantities that can be detected to report drug resistance in a given sample. A brief introduction to MDR, along with a detailed insight into recent biosensor design trends and use for identifying multidrug-resistant microorganisms and tumors, is presented in this review.

Blocking of The Prostaglandin E2 Receptor as a Therapeutic Strategy for Treatment of Breast Cancer: Promising Findings in a Mouse Model

OBJECTIVE

The study aimed to investigate the anticancer effect of E-prostanoid receptor 1 (EP1) antagonist, SC19220, alone or in combination with the COX-2 inhibitor Celecoxob(CXB)® in mice bearing solid Ehrlich carcinoma (SEC).

METHODS

The tumors were induced in 40 female mice, which were divided randomly into four equal groups (n= 10 in each group): Tumor control, CXB, EP1 antagonist, and co-treatment. CXB (10mg/kg) and EP1 antagonist (2mg/kg) were given intraperitoneally every three days, six times in total, then tissue was extracted and prepared for histopathology and measurement of weight, PGE2, and gene expression of EP1 and β 1 integrin.

RESULTS

Both inhibitors, alone or in combination, showed a significant (p<0.001) antitumorigenic effect by decreasing, significantly (p<0.001), each of the tumor weights, tumor volumes, PGE2 levels, EP1 and β1-integrin gene expression along with increasing, significantly (p<0.001), the P53 tumor suppressor protein. The survival rate was improved from 80% in the control group to reach 100% in the treated groups. The co-treatment by CXB and EP1 antagonist showed a marked decrease in tumor weights and volumes as compared with the single treatment. In parallel, the histopathological findings showed enhanced apoptosis and diminished necrosis in the co-treated group.

CONCLUSION

EP1 antagonist proved an antitumorigenic effect alone or combined with CXB and could play a new therapeutic strategy against breast cancer.

ST6Gal1: Oncogenic signaling pathways and targets

The Golgi-sialyltransferase ST6Gal1 (βgalactosidase α2,6 sialyltransferase 1), adds the negatively charged sugar, sialic acid, to the terminal galactose of N-glycosylated proteins. Upregulation of ST6Gal1 is observed in many malignancies, and a large body of research has determined that ST6Gal1-mediated α2,6 sialylation impacts cancer hallmarks. ST6Gal1 affects oncogenic behaviors including sustained proliferation, enhanced self-renewal, epithelial-to-mesenchymal transition, invasion, and chemoresistance. However, there are relatively few ST6GaL1 related signaling pathways that are well-established to mediate these biologies: greater delineation of specific targets and signaling mechanisms that are orchestrated by ST6Gal1 is needed. The aim of this review is to provide a summary of our current understanding of select oncogenic signaling pathways and targets affected by ST6Gal1.

Perspectives on using bacteriophages in biogerontology research and interventions

With the development of materials engineering, gerontology-related research on new tools for diagnostic and therapeutic applications, including precision and personalised medicine, has expanded significantly. Using nanotechnology, drugs can be precisely delivered to organs, tissues, cells, and cell organelles, thereby enhancing their therapeutic effects. Here, we discuss the possible use of bacteriophages as nanocarriers that can improve the safety, efficiency, and sensitivity of conventional medical therapies. Phages are a new class of targeted-delivery vectors, which can carry high concentrations of cargo and protect other nontargeted cells from the senescent cell killing effects of senolytics. Bacteriophages can also be subjected to chemical and/or genetic modifications that would acquire novel properties and improve their ability to detect senescent cells and deliver senolytics. Phage research in experimental biogerontology will also develop strategies to efficiently deliver senolytics, target senescent cells, activate extrinsic apoptosis pathways in senescent cells, trigger immune cells to recognise senescent cells, induce autophagy, promote cell and tissue regeneration, inhibit senescence-associated secretory phenotype (SASP) by senomorphic activity, stimulate the properties of mild stress-inducing hormetic agents and hormetins, and modulate the gut microbiome.

Integrin β1 in Pancreatic Cancer: Expressions, Functions, and Clinical Implications

Simple Summary

Pancreatic cancer (PC) is a highly aggressive malignant tumor with an extremely poor prognosis. Early diagnosis and treatment are key to improving the survival rate of PC patients. Emerging studies show that integrins might contribute to the pathogenesis of PC. This review presents the various signaling pathways that are mediated by integrins in PC and emphasizes the multiple functions of integrin β1 in malignant behaviors of PC. It also discusses the clinical significance of integrin β1 as well as integrin β1-based therapy in PC patients.

Abstract

Pancreatic cancer (PC) is characterized by rapid progression and a high mortality rate. The current treatment is still based on surgical treatment, supplemented by radiotherapy and chemotherapy, and new methods of combining immune and molecular biological treatments are being explored. Despite this, the survival rate of PC patients is still very disappointing. Therefore, clarifying the molecular mechanism of PC pathogenesis and developing precisely targeted drugs are key to improving PC prognosis. As the most common β subunit of the integrin family, integrin β1 has been proved to be closely related to the vascular invasion, distant metastasis, and survival of PC patients, and treatment targeting integrin β1 in PC has gained initial success in animal models. In this review, we summarize the various signaling pathways by which integrins are involved in PC, focusing on the roles of integrin β1 in the malignant behaviors of PC. Additionally, recent studies regarding the feasibility of integrin β1 as a diagnostic and prognostic biomarker in PC are also discussed. Finally, we present the progress of several integrin β1-based clinical trials to highlight the potential of integrin β1 as a target for personalized therapy in PC.

Triazole Modified Tetraiodothyroacetic Acid Conjugated to Polyethylene Glycol, a Thyrointegrin αvβ3 Antagonist as a Radio- and Chemo-Sensitizer in Pancreatic Cancer

Thyroid hormone L thyroxine stimulates pancreatic carcinoma cell proliferation via thyrointegrin αvβ3 receptors, and antagonist tetraiodothyroacetic acid (tetrac) inhibits cancer cell growth. Chemically modified bis-triazole-tetrac conjugated with polyethylene glycol (P-bi-TAT) has higher binding affinity to αvβ3 receptors compared to tetrac. We investigated the antiproliferation effect of P-bi-TAT in pancreatic cancer cells (SUIT2) and its radio- and chemo-sensitizing roles in a mouse model of pancreatic cancer. P-bi-TAT treatment increased tumor-targeted radiation-induced cell death and decreased tumor size. P-bi-TAT acted as a chemo-sensitizer and enhanced the 5-fluorouracil (5FU) effect in decreasing pancreatic tumor weight compared to 5FU monotherapy. Withdrawal of treatment continued the tumor regression; however, the 5FU group showed tumor regrowth. The mechanisms of the anti-cancer activity of P-bi-TAT on SUIT2 cells were assessed by microarray experiments, and genome-wide profiling identified significant alterations of 1348 genes’ expression. Both down-regulated and up-regulated transcripts suggest that a molecular interference at the signaling pathway-associated gene expression is the prevalent mode of P-bi-TAT anti-cancer activity. Our data indicate that non-cytotoxic P-bi-TAT is not only an anti-cancer agent but also a radio-sensitizer and chemo-sensitizer that acts on the extracellular domain of the cell surface αvβ3 receptor.

Characterization of surface markers on extracellular vesicles isolated from lymphatic exudate from patients with breast cancer

BACKGROUND

Breast cancer is the most common cancer, and the leading cause of cancer-related deaths, among females world-wide. Recent research suggests that extracellular vesicles (EVs) play a major role in the development of breast cancer metastasis. Axillary lymph node dissection (ALND) is a procedure in patients with known lymph node metastases, and after surgery large amounts of serous fluid are produced from the axilla. The overall aim was to isolate and characterize EVs from axillary serous fluid, and more specifically to determine if potential breast cancer biomarkers could be identified.

METHODS

Lymphatic drain fluid was collected from 7 patients with breast cancer the day after ALND. EVs were isolated using size exclusion chromatography, quantified and detected by nanoparticle tracking analysis, electron microscopy, nano flow cytometry and western blot. The expression of 37 EV surface proteins was evaluated by flow cytometry using the MACSPlex Exosome kit.

RESULTS

Lymphatic drainage exudate retrieved after surgery from all 7 patients contained EVs. The isolated EVs were positive for the typical EV markers CD9, CD63, CD81 and Flotillin-1 while albumin was absent, indicating low contamination from blood proteins. In total, 24 different EV surface proteins were detected. Eleven of those proteins were detected in all patients, including the common EV markers CD9, CD63 and CD81, cancer-related markers CD24, CD29, CD44 and CD146, platelet markers CD41b, CD42a and CD62p as well as HLA-DR/DP/DQ. Furthermore, CD29 and CD146 were enriched in Her2+ patients compared to patients with Her2- tumors.

CONCLUSIONS

Lymphatic drainage exudate retrieved from breast cancer patients after surgery contains EVs that can be isolated using SEC isolation. The EVs have several cancer-related markers including CD24, CD29, CD44 and CD146, proteins of potential interest as biomarkers as well as to increase the understanding of the mechanisms of cancer biology.

An Update on Molecular Pathways Regulating Vasculogenic Mimicry in Human Osteosarcoma and Their Role in Canine Oncology

Canine tumors are valuable comparative models for human counterparts, especially to explore novel biomarkers and to understand pathways and processes involved in metastasis. Vasculogenic mimicry (VM) is a unique property of malignant cancer cells which promote metastasis. Thus, it represents an opportunity to investigate both the molecular mechanisms and the therapeutic targets of a crucial phenotypic malignant switch. Although this biological process has been largely investigated in different human cancer types, including osteosarcoma, it is still largely unknown in veterinary pathology, where it has been mainly explored in canine mammary tumors. The presence of VM in human osteosarcoma is associated with poor clinical outcome, reduced patient survival, and increased risk of metastasis and it shares the main pathways involved in other type of human tumors. This review illustrates the main findings concerning the VM process in human osteosarcoma, search for the related current knowledge in canine pathology and oncology, and potential involvement of multiple pathways in VM formation, in order to provide a basis for future investigations on VM in canine tumors.

Gold Nanoparticles; Potential Nanotheranostic Agent in Breast Cancer: A Comprehensive Review with Systematic Search Strategy

BACKGROUND

Breast cancer is a heterogeneous disease typically prevalent among women and is the second-largest cause of death worldwide. Early diagnosis is the key to minimize the cancer-induced complication, however, the conventional diagnostic strategies have been sluggish, complex, and, to some extent, non-specific. Therapeutic tools are not so convenient and side effects of current therapies offer the development of novel theranostic tool to combat this deadly disease.

OBJECTIVE

This article aims to summarize the advances in the diagnosis and treatment of breast cancer with gold nanoparticles (GNP or AuNP).

METHODS

A systematic search was conducted in the three popular electronic online databases including PubMed, Google Scholar, and Web of Science, regarding GNP as breast cancer theranostics.

RESULTS

Published literature demonstrated that GNPs tuned with photosensitive moieties, nanomaterials, drugs, peptides, nucleotide, peptides, antibodies, aptamer, and other biomolecules improve the conventional diagnostic and therapeutic strategies of breast cancer management with minimum cytotoxic effect. GNP derived diagnosis system assures reproducibility, reliability, and accuracy cost-effectively. Additionally, surface-modified GNP displayed theranostic potential even in the metastatic stage of breast cancer.

CONCLUSION

Divergent strategies have shown the theranostic potential of surface tuned GNPs against breast cancer even in the metastatic stage with minimum cytotoxic effects both in vitro and in vivo.

Netrin-1 in Glioblastoma Neovascularization: The New Partner in Crime?

Glioblastoma (GBM) is the most aggressive and common primary tumor of the central nervous system. It is characterized by having an infiltrating growth and by the presence of an excessive and aberrant vasculature. Some of the mechanisms that promote this neovascularization are angiogenesis and the transdifferentiation of tumor cells into endothelial cells or pericytes. In all these processes, the release of extracellular microvesicles by tumor cells plays an important role. Tumor cell-derived extracellular microvesicles contain pro-angiogenic molecules such as VEGF, which promote the formation of blood vessels and the recruitment of pericytes that reinforce these structures. The present study summarizes and discusses recent data from different investigations suggesting that Netrin-1, a highly versatile protein recently postulated as a non-canonical angiogenic ligand, could participate in the promotion of neovascularization processes in GBM. The relevance of determining the angiogenic signaling pathways associated with the interaction of Netrin-1 with its receptors is posed. Furthermore, we speculate that this molecule could form part of the microvesicles that favor abnormal tumor vasculature. Based on the studies presented, this review proposes Netrin-1 as a novel biomarker for GBM progression and vascularization.

Molecular and cellular characterization of two patient-derived ductal carcinoma in situ (DCIS) cell lines, ETCC-006 and ETCC-010

BACKGROUND

Currently it is unclear how in situ breast cancer progresses to invasive disease; therefore, a better understanding of the events that occur during the transition to invasive carcinoma is warranted. Here we have conducted a detailed molecular and cellular characterization of two, patient-derived, ductal carcinoma in situ (DCIS) cell lines, ETCC-006 and ETCC-010.

METHODS

Human DCIS cell lines, ETCC-006 and ETCC-010, were compared against a panel of cell lines including the immortalized, breast epithelial cell line, MCF10A, breast cancer cell lines, MCF7 and MDA-MB-231, and another DCIS line, MCF10DCIS.com. Cell morphology, hormone and HER2/ERBB2 receptor status, cell proliferation, survival, migration, anchorage-independent growth, indicators of EMT, cell signalling pathways and cell cycle proteins were examined using immunostaining, immunoblots, and quantitative, reverse transcriptase PCR (qRT-PCR), along with clonogenic, wound-closure and soft agar assays. RNA sequencing (RNAseq) was used to provide a transcriptomic profile.

RESULTS

ETCC-006 and ETCC-010 cells displayed notable differences to another DCIS cell line, MCF10DCIS.com, in terms of morphology, steroid-receptor/HER status and markers of EMT. The ETCC cell lines lack ER/PR and HER, form colonies in clonogenic assays, have migratory capacity and are capable of anchorage-independent growth. Despite being isogenic, less than 30% of differentially expressed transcripts overlapped between the two lines, with enrichment in pathways involving receptor tyrosine kinases and DNA replication/cell cycle programs and in gene sets responsible for extracellular matrix organisation and ion transport.

CONCLUSIONS

For the first time, we provide a molecular and cellular characterization of two, patient-derived DCIS cell lines, ETCC-006 and ETCC-010, facilitating future investigations into the molecular basis of DCIS to invasive ductal carcinoma transition.

Biphasic α2β1 Integrin Expression in Breast Cancer Metastasis to Bone

Integrins participate in the pathogenesis and progression of tumors at many stages during the metastatic cascade. However, current evidence for the role of integrins in breast cancer progression is contradictory and seems to be dependent on tumor stage, differentiation status, and microenvironmental influences. While some studies suggest that loss of α2β1 enhances cancer metastasis, other studies suggest that this integrin is pro-tumorigenic. However, few studies have looked at α2β1 in the context of bone metastasis. In this study, we aimed to understand the role of α2β1 integrin in breast cancer metastasis to bone. To address this, we utilized in vivo models of breast cancer metastasis to bone using MDA-MB-231 cells transfected with an α2 expression plasmid (MDA-OEα2). MDA cells overexpressing the α2 integrin subunit had increased primary tumor growth and dissemination to bone but had no change in tumor establishment and bone destruction. Further in vitro analysis revealed that tumors in the bone have decreased α2β1 expression and increased osteolytic signaling compared to primary tumors. Taken together, these data suggest an inverse correlation between α2β1 expression and bone-metastatic potential. Inhibiting α2β1 expression may be beneficial to limit the expansion of primary tumors but could be harmful once tumors have established in bone.

Cell surface heat shock protein-mediated entry of tumor cell-adapted rotavirus into U-937 cells

Rotaviruses infect cells by binding to specific cell surface molecules including gangliosides, heat shock protein cognate protein 70 (Hsc70), and some integrins. The characterization of cell surface receptors defining viral tropism is crucial for inhibiting entry into the normal cells or the cancer cells. In the present work, several tumor cell-adapted rotavirus isolates were tested for their interaction with some heat shock proteins (HSPs) present in the U-937 cells, derived from a human pleural effusion (histiocytic lymphoma monocyte). This interaction was examined by virus overlay protein-binding (VOPB), immunochemistry, immuno-dot blot assays, and flow cytometry. The results indicated that the rotavirus isolates studied were able to infect U937 cells by interacting with Hsp90, Hsp70, Hsp60, Hsp40, Hsc70, protein disulfide isomerase (PDI), and integrin β3, which are implicated in cellular proliferation, differentiation, and cancer development. Interestingly, these cellular proteins were found to be associated in lipid microdomains (rafts), facilitating in this way eventual sequential interactions of the rotavirus particles with the cell surface receptors. The rotavirus tropism for U937 cells through the use of these cell surface proteins made this rotavirus isolates an attractive target for the development of oncolytic strategies in the context of alternative and complementary treatment of cancer.

Surface Expression of Kynurenine 3-Monooxygenase Promotes Proliferation and Metastasis in Triple-Negative Breast Cancers

Kynurenine 3-monooxygenase (KMO) is the pivotal enzyme in the kynurenine pathway and is located on the mitochondrial outer membrane. The dysregulation of KMO leads to various neurodegenerative diseases; however, it is rarely mentioned in cancer progression. Our previous study showed that KMO overexpression in canine mammary gland tumors (cMGT) is associated with poor prognosis in cMGT patients. Surprisingly, it was also found that KMO can be located on the cell membranes of cMGT cells, unlike its location in normal cells, where KMO is expressed only within the cytosol. Since cMGT and human breast cancer share similar morphologies and pathogenesis, this study investigated the possibility of detecting surface KMO in human breast cancers and the role of surface KMO in tumorigenesis. Using immunohistochemistry (IHC), flow cytometry (FC), immunofluorescence assay (IFA), and transmission electron microscopy (TEM), we demonstrated that KMO can be aberrantly and highly expressed on the cell membranes of breast cancer tissues and in an array of cell lines. Masking surface KMO with anti-KMO antibody reduced the cell viability and inhibited the migration and invasion of the triple-negative breast cancer cell line, MDA-MB-231. These results indicated that aberrant surface expression of KMO may be a potential therapeutic target for human breast cancers.

Apoptosis induction by siRNA targeting integrin-β1 and regorafenib/DDAB-mPEG-PCL hybrid nanoparticles in regorafenib-resistant colon cancer cells

Colorectal cancer (CRC) is regarded as the third most common cancer worldwide. Although Regorafenib as a receptor tyrosine kinase inhibitor (RTKI) disrupts tumor growth and angiogenesis in metastatic CRC (mCRC) patients, drug resistance leads to poor prognosis and survival. Integrin-β1 overexpression has been proposed to be the major player in this regard. Herein, the Regorafenib-resistant human colon cancer cell line (SW-48) was induced, and the Integrin-β1 gene expression, as well as apoptosis, was assessed through the combination of small interfering RNA (siRNA) targeting Integrin-β1 and Regorafenib/Dimethyldioctadecylammonium bromide (DDAB)-methoxy poly (ethylene glycol) (mPEG)-poly-ε-caprolactone (PCL) hybrid nanoparticles (HNPs). In the current study, Regorafenib-resistant SW-48 cell line was generated in which the Regorafenib half-maximal inhibitory concentration (IC₅₀) for non-resistant and resistant cells was 13.5±1.5 µM and 55.1±0.8 µM, respectively. The results of DLS also demonstrated that the size and the charge of the HNPs were equal to 66.56±0.5 nm and +29.5±1.2 mv, respectively. In addition, the Integrin-β1 gene expression was significantly higher in resistant cells than in non-resistant ones (P<0.05). The siRNA/HNP complexes in combination with Regorafenib/HNPs were accordingly identified as the most effective treatment to decrease the Integrin-β1 gene expression and to enhance the apoptosis rate in resistant cells (P<0.001). Overall, the study indicated that combination therapy using siRNA/HNP and Regorafenib/HNPs complex could down-regulate the Integrin-β1 gene expression and consequently trigger apoptosis, and this may potentially induce drug sensitivity.

Molecular Chaperone GRP94/GP96 in Cancers: Oncogenesis and Therapeutic Target

During tumor development and progression, intrinsic and extrinsic factors trigger endoplasmic reticulum (ER) stress and the unfolded protein response, resulting in the increased expression of molecular chaperones to cope with the stress and maintain tumor cell survival. Heat shock protein (HSP) GRP94, also known as GP96, is an ER paralog of HSP90 and has been shown to promote survival signaling during tumor-induced stress and modulate the immune response through its multiple clients, including TLRs, integrins, LRP6, GARP, IGF, and HER2. Clinically, elevated expression of GRP94 correlates with an aggressive phenotype and poor clinical outcome in a variety of cancers. Thus, GRP94 is a potential molecular marker and therapeutic target in malignancies. In this review, we will undergo deep molecular profiling of GRP94 in tumor development and summarize the individual roles of GRP94 in common cancers, including breast cancer, colon cancer, lung cancer, liver cancer, multiple myeloma, and others. Finally, we will briefly review the therapeutic potential of selectively targeting GRP94 for the treatment of cancers.

Male Breast Cancer-Immunohistochemical Patterns and Clinical Relevance of FASN, ATF3, and Collagen IV

Background

Male breast carcinoma (male BC) is an uncommon neoplasia without individualized strategies for diagnosis and therapeutics. Low overall survival (OS) rates have been reported, mostly associated with patients' advanced stage and older age. Intratumoral heterogeneity versus homogeneity of malignant epithelial cells seems to be an important factor to consider for the development of combination therapies with curative intention.

Objective

In this preliminary study, we aim to provide valuable insight into the distinct clinicopathologic features of male BC.

Material and methods

In a series of 40 male BC patients, we evaluated by immunohistochemistry androgen receptor; activating transcription factor 3 (ATF3); p16; cyclin D1; fatty acid synthase (FASN); fatty acid transport protein 1 (FATP1); β1, β3, β4, and β6 integrins; collagen I and collagen IV; and their interactions. Kaplan-Meier survival curves and log-rank tests were assessed for statistical analysis.

Results

Homogeneous epithelial staining of p16, ATF3, β6 integrin, FASN, and FATP1 was found to be significantly intercorrelated, and associated with high Ki67. These markers also stained tumor stromal fibroblasts. The prognostic analysis showed statistically significant associations of FASN with disease-free survival (DFS) and OS, as well as of ATF3 with OS and collagen IV with DFS.

Conclusions

This study highlights, as a novel finding, the relevance of FASN, ATF3, and collagen IV immunophenotypes, which may have innovative application in the clinical management of male BC.

Endoplasmic reticulum oxidoreductase 1 alpha modulates prostate cancer hallmarks

Background

Therapies available for late stage prostate cancer (PCa) patients are limited and mostly palliative. The necessary development of unexplored therapeutic options relies on a deeper knowledge of molecular mechanisms leading to cancer progression. Redox signals are known to modulate the intensity and duration of oncogenic circuits; cues originating from the endoplasmic reticulum (ER) and downstream exocytic organelles are relevant in secretory tumors, including PCa. Ero 1α is a master regulator of redox homeostasis and oxidative folding.

Methods

We assessed Ero 1α mRNA expression by bioinformatic analysis of three public datasets and protein expression levels in PCa cell lines representing different degrees of tumor progression and different human prostate specimens. Transient Ero 1α knockdown was achieved by RNA interference (siRNA). Consequences of Ero 1α downregulation were monitored by PCa proliferation, migration and invasion properties.

Results

Ero 1α mRNA and protein levels are upregulated in PCa cell lines compared to non-tumorigenic cells (P=0.0273). Ero 1α expression increases with the grade of malignancy, reaching the highest level in the androgen resistant PC3. In patients’ samples from 3 datasets, Ero 1α mRNA expression correlates with pathological Gleason scores. Ero 1α knockdown inhibits proliferation (P=0.0081), migration (P=0.0085) and invasion (P=0.0007) of PC3 cells and alters the levels of integrin β1 (P=0.0024).

Conclusions

Results indicate that Ero 1α levels correlate with PCa aggressiveness; Ero 1α silencing inhibits key steps over the PCa metastatic process. Therefore, Ero 1α has the potential to be exploited as a novel biomarker and a therapeutic target in PCa.

Thymoquinone Inhibits Proliferation and Migration of MDA-MB-231 Triple Negative Breast Cancer Cells by Suppressing Autophagy, Beclin-1 and LC3

BACKGROUND

Triple Negative Breast Cancer (TNBC) is an aggressive and highly heterogeneous subtype of breast cancer associated with poor prognosis. A better understanding of the biology of this complex cancer is needed to develop novel therapeutic strategies for the improvement of patient survival. We have previously demonstrated that Thymoquinone (TQ), the major phenolic compound found in Nigella sativa, induces anti-proliferative and anti-metastatic effects and inhibits in vivo tumor growth in orthotopic TNBC models in mice. Also, we have previously shown that Beclin-1 and LC3 autophagy genes contributes to TNBC cell proliferation, migration and invasion, suggesting that Beclin-1 and LC3 genes provide proto-oncogenic effects in TNBC. However, the role of Beclin-1 and LC3 in mediating TQ-induced anti-tumor effects in TNBC is not known.

OBJECTIVE

To investigate the effects of TQ on the major autophagy mediators, Beclin-1 and LC3 expression, as well as autophagic activity in TNBC cells.

METHODS

Cell proliferation, colony formation, migration and autophagy activity were evaluated using MTS cell viability, colony formation assay, wound healing and acridine orange staining assays, respectively. Western blotting and RT-PCR assays were used to investigate LC3 and Beclin-1 protein and gene expressions, respectively, in MDA-MB-231 TNBC cells in response to TQ treatments.

RESULTS

TQ treatment significantly inhibited cell proliferation, colony formation, migration and autophagic activity of MDA-MB-231 cells and suppressed LC3 and Beclin-1 expressions. Furthermore, TQ treatment led to the inhibition of Integrin-β1, VEGF, MMP-2 and MMP-9 in TNBC cells.

CONCLUSION

TQ inhibits autophagic activity and expression of Beclin-1 and LC3 in TNBC cells and suppresses pathways related to cell migration/invasion and angiogenesis, including Integrin-β1, VEGF, MMP-2 and MMP- 9, suggesting that TQ may be used to control autophagic activity and oncogenic signaling in TNBC.

Desialylation of Atg5 by sialidase (Neu2) enhances autophagosome formation to induce anchorage-dependent cell death in ovarian cancer cells

Increased sialylation is one of the hallmarks of ovarian cancer (OC) but its relation with programmed cell death is not known. Here we explored the molecular interplay between autophagy, apoptosis/anoikis, and aberrant-expression of the PI3K-Akt/mTOR pathway in the context of sialidase. OC is accompanied by low expression of cytosolic sialidase (Neu2) and ~10-fold more α2,6- than α2,3-linked sialic acids found through qPCR, western blot, and flow cytometry. Interestingly, Neu2 overexpression cleaved α2,6- and α2,3-linked sialic acids and reduced cell viability. Several autophagy-related molecules like LC3B/Atg3/Atg5/Atg7/Atg12/Atg16L1/Beclin1 were upregulated upon Neu2 overexpression. Atg5, a crucial protein for autophagosome formation, was desialylated by overexpressed Neu2. Desialylated Atg5 now showed enhanced association both with Atg12 and Atg16L1 leading to more autophagosome formation. Neu2-overexpressing cells exhibited extrinsic pathway-mediated apoptosis as reflected the in activation of Fas/FasL/FADD/Bid/caspase 8/caspase 6/caspase 3/PARP cleavage. There was also increased Bax, reduced Bcl2, and several cell-cycle molecules (CDK2/CDK4/CDK6/cyclin-B1/cyclin-E). Inhibition of autophagy using bafilomycin A1 or Beclin1 siRNA leads to reversal of Neu2-induced apoptosis suggesting their possible relationship. Additionally, overexpressed Neu2 inhibited growth factor-mediated signaling molecules involved in the PI3K/Akt-mTOR pathway probably through their desialylation. Furthermore, overexpressed Neu2 inhibited epithelial (ZO-1/Claudin1), mesenchymal (snail/slug), and cell-adhesion (integrin-β3/focal-adhesion kinase) molecules suggesting anchorage-dependent cell death (anoikis). Such changes were absent in the presence of bafilomycin A1 indicating the involvement of autophagy in Neu2-induced anoikis. The physiological relevance of our in vitro observations was further confirmed in the OC xenograft model. Taken together, it is the first report demonstrating that Atg5 is a sialoglycoprotein having α2,6- and α2,3-linked sialic acids and its desialylation by overexpressed Neu2 leads to its activation for autophagosome formation, which induced apoptosis/anoikis in OC.

Thy-1 (CD90)-Induced Metastatic Cancer Cell Migration and Invasion Are β3 Integrin-Dependent and Involve a Ca2+/P2X7 Receptor Signaling Axis

Cancer cell adhesion to the vascular endothelium is an important step in tumor metastasis. Thy-1 (CD90), a cell adhesion molecule expressed in activated endothelial cells, has been implicated in melanoma metastasis by binding to integrins present in cancer cells. However, the signaling pathway(s) triggered by this Thy-1-Integrin interaction in cancer cells remains to be defined. Our previously reported data indicate that Ca²⁺-dependent hemichannel opening, as well as the P2X7 receptor, are key players in Thy-1-α_Vβ₃ Integrin-induced migration of reactive astrocytes. Thus, we investigated whether this signaling pathway is activated in MDA-MB-231 breast cancer cells and in B16F10 melanoma cells when stimulated with Thy-1. In both cancer cell types, Thy-1 induced a rapid increase in intracellular Ca²⁺, ATP release, as well as cell migration and invasion. Connexin and Pannexin inhibitors decreased cell migration, implicating a requirement for hemichannel opening in Thy-1-induced cell migration. In addition, cell migration and invasion were precluded when the P2X7 receptor was pharmacologically blocked. Moreover, the ability of breast cancer and melanoma cells to transmigrate through an activated endothelial monolayer was significantly decreased when the β₃ Integrin was silenced in these cancer cells. Importantly, melanoma cells with silenced β₃ Integrin were unable to metastasize to the lung in a preclinical mouse model. Thus, our results suggest that the Ca²⁺/hemichannel/ATP/P2X7 receptor-signaling axis triggered by the Thy-1-α_Vβ₃ Integrin interaction is important for cancer cell migration, invasion and transvasation. These findings open up the possibility of therapeutically targeting the Thy-1-Integrin signaling pathway to prevent metastasis.

Engineering of biomaterials for tumor modeling

Development of biomaterials mimicking tumor and its microenvironment has recently emerged for the use of drug discovery, precision medicine, and cancer biology. These biomimetic models have developed by reconstituting tumor and stroma cells within the 3D extracellular matrix. The models are recently extended to recapitulate the in vivo tumor microenvironment, including biological, chemical, and mechanical conditions tailored for specific cancer type and its microenvironment. In spite of the recent emergence of various innovative engineered tumor models, many of these models are still early stage to be adapted for cancer research. In this article, we review the current status of biomaterials engineering for tumor models considering three main aspects - cellular engineering, matrix engineering, and engineering for microenvironmental conditions. Considering cancer-specific variability in these aspects, our discussion is focused on pancreatic cancer, specifically pancreatic ductal adenocarcinoma (PDAC). In addition, we further discussed the current challenges and future opportunities to create reliable and relevant tumor models.

Proteomic Approach for Searching for Universal, Tissue-Specific, and Line-Specific Markers of Extracellular Vesicles in Lung and Colorectal Adenocarcinoma Cell Lines

Tumor-derived extracellular vesicles (EVs), including exosomes, contain proteins that mirror the molecular landscape of producer cells. Being potentially detectible in biological fluids, EVs are of great interest for the screening of cancer biomarkers. To reveal universal, tissue-specific, and line-specific markers, we performed label-free mass spectrometric profiling of EVs originating from the human colon cancer cell lines Caco-2, HT29, and HCT-116, as well as from the lung cancer cell lines NCI-H23 and A549. A total of 651 proteins was identified in the EV samples using at least two peptides. These proteins were highly enriched in exosome markers. We found 11 universal, eight tissue-specific, and 29 line-specific markers, the levels of which were increased in EVs compared to the whole lysates. The EV proteins were involved in the EGFR, Rap1, integrin, and microRNA signaling associated with metastasis and cancer progression. An EV protein-based assay could be developed as a liquid biopsy tool.

Inadequate tissue mineralization promotes cancer cell attachment

Bone metastases are a frequent complication in prostate cancer, and several studies have shown that vitamin D deficiency promotes bone metastases. However, while many studies focus on vitamin D’s role in cell metabolism, the effect of chronically low vitamin D levels on bone tissue, i.e. insufficient mineralization of the tissue, has largely been ignored. To investigate, whether poor tissue mineralization promotes cancer cell attachment, we used a fluorescence based adhesion assay and single cell force spectroscopy to quantify the adhesion of two prostate cancer cell lines to well-mineralized and demineralized dentin, serving as biomimetic bone model system. Adhesion rates of bone metastases-derived PC3 cells increased significantly on demineralized dentin. Additionally, on mineralized dentin, PC3 cells adhered mainly via membrane anchored surface receptors, while on demineralized dentin, they adhered via cytoskeleton-anchored transmembrane receptors, pointing to an interaction via exposed collagen fibrils. The adhesion rate of lymph node derived LNCaP cells on the other hand is significantly lower than that of PC3 and not predominately mediated by cytoskeleton-linked receptors. This indicates that poor tissue mineralization facilitates the adhesion of invasive cancer cells by the exposure of collagen and emphasizes the disease modifying effect of sufficient vitamin D for cancer patients.

Evaluation of the diagnostic ability of laminin gene family for pancreatic ductal adenocarcinoma

A poor outcome for pancreatic ductal adenocarcinoma (PDAC) patients is still a challenge worldwide. The aim of our study is to investigate the potential of key laminin subunits for being used both as a diagnostic and prognostic biomarker for PDAC patients. We evaluated the mRNA expression and prognostic value of laminin gene family in PDAC tissues using online public databases. Moreover, the relationship between key laminin subunits in PDAC blood cells and circulating tumor cells (CTCs) and the distinguishing ability of joint serum levels with carbohydrate antigen 19-9 (CA19-9) was analyzed. Two key differentially expressed subunits (LAMA3 and LAMC2) that are associated with prognosis of PDAC patients were found to show a potential for distinguishing between PDAC and non-tumor tissues. LAMA3 and LAMC2 expression were found to be positively related with CTC quantity in PDAC blood (R=0.628, p=0.029; R=0.776, p=0.003, respectively) using IgG chips. Furthermore, serum LAMC2 levels offered significant improvement over using CA19-9 alone for the discrimination of PDAC. Joint serum LAMC2 and CA19-9 levels increased the net benefit proportion in early stage/operational PDAC patients. Using integrated profiling, we identified LAMA3 and LAMC2 as potential therapeutic targets and prognostic markers for PDAC, for which further validation is warranted.

Use of peripheral blood transcriptomic biomarkers to distinguish high-grade cervical squamous intraepithelial lesions from low-grade lesions

It is crucial to classify cervical lesions into high-grade squamous intraepithelial lesions (HSILs) and low-grade SILs (LSILs), as LSILs are conservatively treated by observation, based on an expectation of natural regression, whereas HSILs usually require electrosurgical excision. In the present study, peripheral blood gene expression profiles were analyzed to identify transcriptomic biomarkers distinguishing HSILs from LSILs. A total of 102 blood samples were collected from women with cervical SILs (66 HSIL and 36 LSIL) for microarray hybridization. Candidate gene signatures were identified using AdaBoost algorithms, and a predictive model was constructed using logistic regression to differentiate HSILs from LSILs. To correct for possible bias as a result of the limited sample size and to verify the stability of the predictive model, a two-fold cross validation and null set analysis was conducted over 1,000 iterations. The functions of the transcriptomic biomarkers were then analyzed to elucidate the pathogenesis of cervical SIL. A total of 10 transcriptomic genes (STMN3, TRPC4AP, DYRK2, AGK, KIAA0319L, GRPEL1, ZFC3H1, LYL1, ITGB1 and ARHGAP18) were identified. The predictive model based on the 10-gene panel exhibited well-discriminated power. A cross validation process using known disease status exhibited almost the same performance as that of the predictive model, whereas null-set analysis with randomly reassigned disease status exhibited much lower predictive performance for distinguishing HSILs from LSILs. These biomarkers were involved in the 'Rho GTPase cycle', 'mitochondrial protein import', 'oncogenic MAPK signaling', 'integrin cell surface interaction' and 'signaling by BRAF and RAF fusions'. In conclusion, peripheral blood gene expression analysis is a promising method for distinguishing HSILs from LSILs. The present study proposes 10 candidate genes that could be used in the future as diagnostic biomarkers and potential therapeutic targets for cervical SILs. A simple, non-invasive blood test would be clinically useful in the diagnosis and classification of patients with cervical SILs.

Interactions between Bacteriophages and Eukaryotic Cells

As the name implies, bacteriophage is a bacterium-specific virus. It infects and kills the bacterial host. Bacteriophages have gained attention as alternative antimicrobial entities in the science community in the western world since the alarming rise of antibiotic resistance among microbes. Although generally considered as prokaryote-specific viruses, recent studies indicate that bacteriophages can interact with eukaryotic organisms, including humans. In the current review, these interactions are divided into two categories, i.e., indirect and direct interactions, with the involvement of bacteriophages, bacteria, and eukaryotes. We discuss bacteriophage-related diseases, transcytosis of bacteriophages, bacteriophage interactions with cancer cells, collaboration of bacteriophages and eukaryotes against bacterial infections, and horizontal gene transfer between bacteriophages and eukaryotes. Such interactions are crucial for understanding and developing bacteriophages as the therapeutic agents and pharmaceutical delivery systems. With the advancement and combination of in silico, in vitro, and in vivo approaches and clinical trials, bacteriophages definitely serve as useful repertoire for biologic target-based drug development to manage many complex diseases in the future.

Biomarkers of tumor invasiveness in proteomics (Review)

Over the past two decades, quantitative proteomics has emerged as an important tool for deciphering the complex molecular events involved in cancers. The number of references involving studies on the cancer metastatic process has doubled since 2010, while the last 5 years have seen the development of novel technologies combining deep proteome coverage capabilities with quantitative consistency and accuracy. To highlight key findings within this huge amount of information, the present review identified a list of tumor invasive biomarkers based on both the literature and data collected on a biocollection of experimental cell lines, tumor models of increasing invasiveness and tumor samples from patients with colorectal or breast cancer. Crossing these different data sources led to 76 proteins of interest out of 1,245 mentioned in the literature. Information on these proteins can potentially be translated into clinical prospects, since they represent potential targets for the development and evaluation of innovative therapies, alone or in combination. Herein, a systematical review of the biology of each of these proteins, including their specific subcellular/extracellular or multiple localizations is presented. Finally, as an important advantage of quantitative proteomics is the ability to provide data on all these molecules simultaneously in cell pellets, body fluids or paraffin‑embedded sections of tumors/invaded tissues, the significance of some of their interconnections is discussed.

MicroRNA-374b mediates the initiation of non-small cell lung cancer by regulating ITGB1 and p53 expressions

Background

Previous studies have shown that microRNAs (miRNAs) play important roles in the pathogenesis of human cancers. This study aims to clarify the role of miR‐374b in non‐small cell lung cancer (NSCLC).

Methods

In this study, RT‐qPCR and western blot analysis were used to measure mRNA and protein expression. The regulatory mechanism of miR‐374b/ITGB1 was investigated by dual‐luciferase reporter, CCK‐8, and transwell assays.

Results

MiR‐374b expression was reduced in NSCLC tissues and associated with lymph node metastasis, tumor stage and prognosis in NSCLC patients. Functionally, overexpression of miR‐374b inhibited cell viability and metastasis in NSCLC. In addition, miR‐374b blocked EMT and promoted p53 expression in NSCLC. MiR‐374b was found to directly target ITGB1. Furthermore, upregulation of ITGB1 weakened the antitumor effect of miR‐374b in NSCLC.

Conclusions

MiR‐374b inhibits the tumorigenesis of NSCLC by downregulating ITGB1 and upregulating p53.

Integrin beta 4 (ITGB4) and its tyrosine-1510 phosphorylation promote pancreatic tumorigenesis and regulate the MEK1-ERK1/2 signaling pathway

Pancreatic cancer is the fourth leading cause of cancer death, with a 5-year survival rate of only 1–4%. Integrin-mediated cell adhesion is critical for the initiation, progression, and metastasis of cancer. In this study we investigated the role of integrin β4 (ITGB4) and its phosphorylation at tyrosine Y1510 (p-ITGB4-Y1510) in the tumorigenesis of pancreatic cancer. We analyzed the expression of ITGB4 and p-ITGB4-Y1510 in pancreatic cancer tissue and cell lines using immunohistochemistry, Western blot, or semi-quantitative reverse transcription PCR. ITGB4 and p-ITGB4-Y1510 were highly expressed in pancreatic cancer (n = 176) compared with normal pancreatic tissue (n = 171). High p-ITGB4-Y1510 expression correlated with local invasion and distant metastasis of pancreatic cancer, and high ITGB4 was significantly associated with poor survival of patients. Inhibition of ITGB4 by siRNA significantly reduced migration and invasion of PC-1.0 and AsPC-1 cells. Overexpression of the mutant ITGB4-Y1510A (a mutation of tyrosine to alanine at 1510 position) in PC-1.0 and AsPC-1 cells not only blocked the ITGB4 phosphorylation at Y1510 but also suppressed the expression of ITGB4 (p < 0.05 vs. wild-type ITGB4). The transfection of PC-1.0 and AsPC-1 cells with ITGB4-Y1510A significantly decreased the level of p-mitogen-activated protein kinase kinase (MEK)1 (T292) and p-extracellular signal-regulated kinase (ERK)1/2 but did not affect the level of p-MEK1 (T386) and p-MEK2 (T394). Overall, our study showed that ITGB4 and its phosphorylated form promote cell migration and invasion in pancreatic cancer and that p-ITGB4-Y1510 regulates the downstream MEK1-ERK1/2 signaling cascades. Targeting ITGB4 or its phosphorylation at Y1510 may be a novel therapeutic option for pancreatic cancer.

Materials-Based Approach for Interrogating Human Prostate Cancer Cell Adhesion and Migratory Potential Using a Fluoroalkylsilica Culture Surface

OPCT-1 is a heterogeneous prostate cancer cell line derived from primary (rather than metastatic) disease which contains epithelial, mesenchymal, and CD44^high/CD24^low cancer stem cell (CSC) subpopulations and from which we have previously generated and characterized stable mesenchymal (P4B6B) and epithelial (P5B3) cell subpopulations. In this contribution, we explore the effect of tissue culture surface chemistry (standard tissue culture plastic (TCP) and a fluoroalkylsilica (FS) culture surface with inherently low surface energy) on the phenotype and adherent capacity of mesenchymal and epithelial cell populations. We demonstrate that OPCT-1 cells adherent to FS surfaces comprise both epithelial- and mesenchymal-like populations; a mesenchymal subpopulation derived from OPCT1 (P4B6B) poorly adheres to FS and formed spheroids, whereas an epithelial subpopulation derived from OPCT1 (P5B3) forms an adherent monolayer. In contrast, P4B6B cells do adhere to FS when cocultured with P5B3 cells. Taken together, these findings demonstrate that EMT/cell differentiation status dictates cell adhesive capacity and provide a novel insight into the relationship between epithelial and mesenchymal cell populations in metastasis. Importantly, the differences in adherence capacity between P4B6B and P5B3 are not apparent using standard TCP-based culture, thereby highlighting the value of using alternative culture surfaces for studying cell surface interaction/adhesion phenomena and interrogating mechanisms involved in adhesion and detachment of metastatic tumor cells.

Downregulated Circular RNA hsa_circ_0000291 Suppresses Migration And Proliferation Of Gastric Cancer Via Targeting The miR-183/ITGB1 Axis

Background

Circular RNAs are implicated in a variety of cancers. This investigation found that hsa_circ_0000291 expression was upregulated in gastric cancer (GC) cell lines, yet its role in GC has not yet been reported.

Objective

To explore the effects of hsa_circ_0000291 on GC cell proliferation and invasion.

Materials and methods

In the current research, we used the gastric cancer cell lines MGC803 and MKN-28 to study hsa_circ_0000291 function. The relationship between hsa_circ_0000291, miR-183 and ITGB1 was analyzed by firefly luciferase analysis and Western blots, and qRT-PCR approaches were used for protein and gene expression analysis, respectively. Tumor growth and metastasis were determined in nude mice xenografts using MKN-28 cells, with or without hsa_circ_000r0291 downregulation.

Results

Our data showed that hsa_circ_0000291 was upregulated in GC cell lines, whereas hsa_circ_0000291 silencing suppressed cell metastasis and proliferation in in vivo and in vitro studies. Our results showed that the downregulation of hsa_circ_0000291 suppressed integrin beta 1 (ITGB1) expression via miR-183 “sponging,” which was validated by rescue experiments using the luciferase reporter assay. Our observations suggested that hsa_circ_0000291 silencing suppressed the aggressive, metastatic GC phenotype.

Conclusion

Taken together, hsa_circ_0000291 knockdown inhibited GC cell metastasis and growth by regulating the miR-183/ITGB1 axis. Importantly, this approach could provide a therapy target and potential biomarker for the diagnosis and treatment of GC.

A disintegrin and metalloprotease 23 hypermethylation predicts decreased disease-free survival in low-risk breast cancer patients

A Disintegrin And Metalloprotease 23 (ADAM23), a member of the ADAM family, is involved in neuronal differentiation and cancer. ADAM23 is considered a possible tumor suppressor gene and is frequently downregulated in various types of malignancies. Its epigenetic silencing through promoter hypermethylation was observed in breast cancer (BC). In the present study, we evaluated the prognostic significance of ADAM23 promoter methylation for hematogenous spread and disease-free survival (DFS). Pyrosequencing was used to quantify ADAM23 methylation in tumors of 203 BC patients. Presence of circulating tumor cells (CTC) in their peripheral blood was detected by quantitative RT-PCR. Expression of epithelial (KRT19) or mesenchymal (epithelial-mesenchymal transition [EMT]-inducing transcription factors TWIST1, SNAI1, SLUG and ZEB1) mRNA transcripts was examined in CD45-depleted peripheral blood mononuclear cells. ADAM23 methylation was significantly lower in tumors of patients with the mesenchymal CTC (P = .006). It positively correlated with Ki-67 proliferation, especially in mesenchymal CTC-negative patients (P = .001). In low-risk patients, characterized by low Ki-67 and mesenchymal CTC absence, ADAM23 hypermethylation was an independent predictor of DFS (P = .006). Our results indicate that ADAM23 is likely involved in BC progression and dissemination of mesenchymal CTC. ADAM23 methylation has the potential to function as a novel prognostic marker and therapeutic target.

Randomly Distributed K14+ Breast Tumor Cells Polarize to the Leading Edge and Guide Collective Migration in Response to Chemical and Mechanical Environmental Cues

Collective cell migration is an adaptive, coordinated interactive process involving cell-cell and cell-extracellular matrix (ECM) microenvironmental interactions. A critical aspect of collective migration is the sensing and establishment of directional movement. It has been proposed that a subgroup of cells known as leader cells localize at the front edge of a collectively migrating cluster and are responsible for directing migration. However, it is unknown how and when leader cells arrive at the front edge and what environmental cues dictate leader cell development and behavior. Here, we addressed these questions by combining a microfluidic device design that mimics multiple tumor microenvironmental cues concurrently with biologically relevant primary, heterogeneous tumor cell organoids. Prior to migration, breast tumor leader cells (K14⁺) were present throughout a tumor organoid and migrated (polarized) to the leading edge in response to biochemical and biomechanical cues. Impairment of either CXCR4 (biochemical responsive) or the collagen receptor DDR2 (biomechanical responsive) abrogated polarization of leader cells and directed collective migration. This work demonstrates that K14⁺ leader cells utilize both chemical and mechanical cues from the microenvironment to polarize to the leading edge of collectively migrating tumors. SIGNIFICANCE: These findings demonstrate that pre-existing, randomly distributed leader cells within primary tumor organoids use CXCR4 and DDR2 to polarize to the leading edge and direct migration.

MicroRNAs as Potential Targets for Therapeutic Intervention With Metastasis of Non-small Cell Lung Cancer

The death toll of non-small cell lung cancer (NSCLC) patients is primarily due to metastases, which are poorly amenable to therapeutic intervention. In this review we focus on miRs associated with metastasis of NSCLC as potential new targets for anti-metastatic therapy. We discuss miRs validated as therapeutic targets by in vitro data, identification of target(s) and pathway(s) and in vivo efficacy data in at least one clinically-relevant metastasis-related model. A few of the discussed miRs correlate with the clinical status of NSCLC patients. Using miRs as therapeutic agents has the advantage that targeting a single miR can potentially interfere with several metastatic pathways. Depending on their mode of action, the corresponding miRs can be up- or down-regulated compared to normal matching tissues. Here, we describe therapeutic approaches for reconstitution therapy and miR inhibition, general principles of anti-metastatic therapy as well as current technical pitfalls.

DT-13 Inhibits Proliferation and Metastasis of Human Prostate Cancer Cells Through Blocking PI3K/Akt Pathway

DT-13, a saponin monomer 13 from the dwarf lilyturf tuber, was reported to exhibit anti-inflammatory, hepatoprotective, cardioprotective as well as antitumor activities in a number of tumor cells. Prostate cancer is the second leading cause of cancer death in males, discovery of novel antitumor drug for therapy of prostate cancer is expected. Aiming to evaluate whether DT-13 could become a candidate to treat prostate cancer, we recently investigated the antitumor effect of DT-13 on human prostate cancer cells and the underlying mechanism. DT-13 was found to effectively inhibit proliferation and metastasis of prostate cancer PC3 and DU145 cell lines in a dose-dependent manner. Treatment by DT-13 resulted in a mitochondria-mediated apoptosis, which was accompanied by the chromatin condensation and nuclear shrinkage in the prostate cancer cells. Moreover, DT-13 caused remarkable upregulation of Bax, Bad, Cytochrome C, cleaved -caspase 3, -caspase 9 and -PARP, in contrast to the downregulation of Bcl-2. Nevertheless, no obvious change in intracellular ROS level was observed after DT-13 treatment. We further demonstrated that DT-13 could inhibit PC3 cell metastasis in which suppression of Integrinβ1 and MMP2/9 might be involved. Western blot analysis indicated DT-13 significantly decreased the phosphorylation of PDK1, Akt, mTOR as well as p70S6K, suggesting the pro-apoptotic and anti-metastatic effects of DT-13 on prostate cancer cells might be attributed to the blockade of PI3K/Akt pathway. Collectively, our findings suggest DT-13 is worthy of further investigation as a drug candidate for the treatment of prostate cancer.

MicroRNA-183-5p Inhibits Aggressiveness of Cervical Cancer Cells by Targeting Integrin Subunit Beta 1 (ITGB1)

Background

Accumulating studies demonstrate that microRNAs play crucial roles in multiple processes of cancer progression. Lower levels of miR-183 have ben observed in diverse types of tumors but the mechanism and precise function of miR-183-5p in cervical cancer have largely not been investigated.

Material/Methods

The level of miR-183-5p in different cervical cancer cell lines and clinical tissues was detected qRT-PCR assays. Transwell and wound-healing migration assays were conducted to assess the functional roles of miR-183-5p in over-expressing cervical cancer cells in vitro. Rescue assays were carried out to confirm the contribution of integrin subunit Beta 1 (ITGB1) to the aggressiveness of cancer cells regulated by miR-183-5p.

Results

miR-183-5p was reduced in clinical tissues of cervical cancer and cell lines when compared to the normal subjects and normal cervical epithelial cell line, respectively. In addition, over-expression of miR-183-5p markedly inhibited migration and invasion in cervical cancer cells, and increased aggressiveness was observed in miR-183-5p inhibitor transfected cells. Furthermore, the luciferase reporter assays revealed that ITGB1 was the gene directly regulated by miR-183-5p. Notably, a negative association between the ITGB1 and miR-183-5p was found, and the gene expressions of ITGB1 was mediated by miR-183-5p in cervical cancer cells.

Conclusions

miR-183-5p serves as a latent anti-oncogene by targeting the metastasis-promoter gene, ITGB1.

HDAC Inhibition Counteracts Metastatic Re-Activation of Prostate Cancer Cells Induced by Chronic mTOR Suppression

This study was designed to investigate whether epigenetic modulation by histone deacetylase (HDAC) inhibition might circumvent resistance towards the mechanistic target of rapamycin (mTOR) inhibitor temsirolimus in a prostate cancer cell model. Parental (par) and temsirolimus-resistant (res) PC3 prostate cancer cells were exposed to the HDAC inhibitor valproic acid (VPA), and tumor cell adhesion, chemotaxis, migration, and invasion were evaluated. Temsirolimus resistance was characterized by reduced binding of PC3^res cells to endothelium, immobilized collagen, and fibronectin, but increased adhesion to laminin, as compared to the parental cells. Chemotaxis, migration, and invasion of PC3^res cells were enhanced following temsirolimus re-treatment. Integrin α and β receptors were significantly altered in PC3^res compared to PC3^par cells. VPA significantly counteracted temsirolimus resistance by down-regulating tumor cell–matrix interaction, chemotaxis, and migration. Evaluation of integrin expression in the presence of VPA revealed a significant down-regulation of integrin α5 in PC3^res cells. Blocking studies demonstrated a close association between α5 expression on PC3^res and chemotaxis. In this in vitro model, temsirolimus resistance drove prostate cancer cells to become highly motile, while HDAC inhibition reversed the metastatic activity. The VPA-induced inhibition of metastatic activity was accompanied by a lowered integrin α5 surface level on the tumor cells.

Role of extracellular matrix in breast cancer development: a brief update

Evidence is increasing on the crucial role of the extracellular matrix (ECM) in breast cancer progression, invasion and metastasis with almost all mortality cases owing to metastasis. The epithelial-mesenchymal transition is the first signal of metastasis involving different transcription factors such as Snail, TWIST, and ZEB1. ECM remodeling is a major event promoting cancer invasion and metastasis; where matrix metalloproteinases (MMPs) such as MMP-2, -9, -11, and -14 play vital roles degrading the matrix proteins for cancer spread. The β-D mannuronic acid (MMP inhibitor) has anti-metastatic properties through inhibition of MMP-2, and -9 and could be a potential therapeutic agent. Besides the MMPs, the enzymes such as LOXL2, LOXL4, procollagen lysyl hydroxylase-2, and heparanase also regulate breast cancer progression. The important ECM proteins like integrins (b1-, b5-, and b6- integrins), ECM1 protein, and Hic-5 protein are also actively involved in breast cancer development. The stromal cells such as tumor-associated macrophages (TAMs), cancer-associated fibroblasts (CAFs), and adipocytes also contribute in tumor development through different processes. The TAMs become proangiogenic through secretion of VEGF-A and building vessel network for nourishment and invasion of the tumor mass. The latest developments of ECM involvement in breast cancer progression has been discussed in this review and this study will help researchers in designing future work on breast cancer pathogenesis and developing therapy targeted to the ECM components.