Acquisition Of Metastatic Phenotype Research Articles

Deciphering the Molecular Basis of Melatonin Protective Effects on Breast Cells Treated with Doxorubicin: TWIST1 a Transcription Factor Involved in EMT and Metastasis, a Novel Target of Melatonin.

Melatonin mitigates cancer initiation, progression and metastasis through inhibition of both the synthesis of estrogens and the transcriptional activity of the estradiol-ER (Estrogen receptor) complex in the estrogen-dependent breast cancer cell line MCF-7. Moreover, melatonin improves the sensitivity of MCF-7 to chemotherapeutic agents and protects against their side effects. It has been described that melatonin potentiates the anti-proliferative effects of doxorubicin; however, the molecular changes involving gene expression and the activation/inhibition of intracellular signaling pathways remain largely unknown. Here we found that melatonin enhanced the anti-proliferative effect of doxorubicin in MCF-7 but not in MDA-MB-231 cells. Strikingly, doxorubicin treatment induced cell migration and invasion, and melatonin effectively counteracted these effects in MCF-7 but not in estrogen-independent MDA-MB-231 cells. Importantly, we describe for the first time the ability of melatonin to downregulate TWIST1 (Twist-related protein 1) in estrogen-dependent but not in estrogen-independent breast cancer cells. Combined with doxorubicin, melatonin inhibited the activation of p70S6K and modulated the expression of breast cancer, angiogenesis and clock genes. Moreover, melatonin regulates the levels of TWIST1-related microRNAs, such as miR-10a, miR-10b and miR-34a. Since TWIST1 plays a pivotal role in the epithelial to mesenchymal transition, acquisition of metastatic phenotype and angiogenesis, our results suggest that inhibition of TWIST1 by melatonin might be a crucial mechanism of overcoming resistance and improving the oncostatic potential of doxorubicin in estrogen-dependent breast cancer cells.

Abstract 3969: AF1q/Mllt11 regulates the expression of intercellular adhesion molecule-1 in breast cancer

Abstract Intercellular adhesion molecule-1 (ICAM-1) is a cell surface glycoprotein in the immunoglobulin superfamily. ICAM-1 expression is frequently observed on many cell types including endothelial cells and different cancer cell entities. Experimental data strongly indicate that ICAM-1 can activate intracellular signaling pathways in cancer cells leading to enhanced cell motility, invasion and metastasis. In clinical investigation, however, ICAM-1 expression was negatively correlated to tumor size, lymph node metastasis, and tumor infiltration. Also, there was improved relapse-free and overall survival in patients with ICAM-1 positive tumors. Yet, the function of ICAM-1 expression during malignant progression in breast cancer patients is not understood clearly. However, ICAM-1 is still considered as a breast cancer target and biomarker may lead to the development of a new strategy and platform for breast cancer patients. We observed AF1q, a metastasis enhancer, is only expressed in metastatic cells, MDA-MB-231LN (invasive sub line from MDA-MB-231), not in the primary tumor cells. To investigate whether AF1q has a responsibility in acquisition of metastatic phenotype, we performed RNA-Seq and applied the Metacore network building algorithm. Intriguingly, most genes were directly linked with Intercellular Adhesion Molecule-1 (ICAM-1). Likewise, we identified that ICAM-1 expression is attenuated in MDA-MB-231LN compared to MDA-MB-231. Moreover, the expression of ICAM-1 was negatively regulated, when AF1q was overexpressed in MDA-MD-231LN. Suppressed endogenous AF1q by shRNA could effectively increase the ICAM-1 expression. Attenuation of ICAM-1 by AF1q on tumor cells would disadvantage host anti-tumor defenses by trafficking of lymphocytes, which affect tumor progression and metastasis. We observed that NF-κB activity which regulates ICAM-1 expression is attenuated in response to AF1q expression in breast cancer cells. Published reports shown that Wnt/β-catenin negatively regulates NF-κB activity through protein-protein interaction in colon and breast cancer cells. Previously, we reported that AF1q enhance the TCF7/LEF/β-catenin complex binding affinity as a cofactor. Structurally, AF1q has highly acidic peptide regions highly conserved between species that fulfill the criteria for an acidic blob, a typical feature for cofactors. When we performed immunoprecipitation with NF-κB antibody in MDA-MB-231LN overexpressed AF1q, we observed that β-catenin and AF1q were pulled down together. However, it is not clear yet whether AF1q promote protein interaction between β-catenin and NF-κB. These results suggest that activated β-catenin by AF1q would archive higher affinity to bind with NF-κB and thereby attenuate ICAM-1 expression. Citation Format: Jino Park, Soojin Kim, William Tse. AF1q/Mllt11 regulates the expression of intercellular adhesion molecule-1 in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3969. doi:10.1158/1538-7445.AM2017-3969

Downregulation of β3 integrin by miR-30a-5p modulates cell adhesion and invasion by interrupting Erk/Ets‑1 network in triple-negative breast cancer.

Integrins are adhesion receptors involved in bidirectional signaling and are crucial for various cellular responses during normal homeostasis and pathological conditions, such as cancer progression and metastasis. In the present study, we demonstrated that blockage of β3 integrin-mediated cell- extracellular matrix interactions restrained triple-negative breast cancer (TNBC) growth, and elevated β3 integrin can trigger the rewiring of Erk/Ets-1 signaling pathways, thereby enhancing cell growth and invasion. Ectopic expression of miRNA has been implicated in the deregulation of integrin expression and activity, blocking of cancer tumor development and progression, and acquisition of metastatic phenotype. miR-30a-5p expression has been implicated in the progression of breast cancer. Overexpression of miR-30a-5p suppressed the proliferation, migration and invasion of breast cancer cells. On the contrary, inhibition of miR-30a-5p promoted the proliferation, migration, and invasion of TNBC cells by suppressing the expression of ERK/Ets-1 signal. An inverse correlation was found between the mRNA expressions of miR-30a-5p and β3 integrin in TNBC samples. Furthermore, bioinformatics analysis revealed the putative miR-30 binding sites in the 3'-UTR of β3 integrin. Results of luciferase assay revealed a strong repression of luciferase activity after transfection with miR‑30a-5p and wild-type 3'-UTR of β3 integrin. In TNBC cells, miR-30a-5p promoted an epithelial phenotype and suppressed invasion by specifically targeting β3 integrin subunit to subsequently interdict the β3 integrin/Erk/Ets-1 network.

Abstract C292: Inhibition of carbonic anhydrase (9 and 12) decreases cell proliferation and gene expression in human glioblastoma cell.

Abstract Propose: Glioblastoma (GB) is the most common and lethal malignant primary brain tumor, representing up to 50% of all primary brain gliomas, and carries the poorest prognosis. An important factor for tumor progression is the acidification of the environment that is promoted by carbonic anhydrases (CAs) 9 and 12, directing to the acquisition of metastatic phenotype and chemoresistance to anticancer drugs. Indisulam is a novel anticancer drug with potent inhibition of CAs. It has in vitro and in vivo activity and prevents cell cycle progression in tumor cells, downregulates genes involved in cytotoxic drug resistence and cell proliferation. The aim this study was to evaluate the expression and the effects of inhibition of the 9/12 CAs by indisulam in proliferation and in gene expression of GB cell lines subjected to normoxia or hypoxia. Materials and Method: The U87-MG, U251, U138-MG, U343-MG-a adult GB cell lines were cultured in conditions of hypoxia or normoxia. Functional studies of cell proliferation and clonogenic capacity were performed in triplicate with Indisulan at different concentrations during 24, 48 and 72h. Gene expression of CA9, CA12, VEGF and HIF1α was assessed using qRT-PCR. Statistical analysis was made by one-way ANOVA and Bonferoni post-hoc. Results: Indisulam displayed inhibitory characteristics to hypoxia induced CA9/CA12 expression in the four GBM cell lines. All experiments showed that the inhibition of CA9/12 with indisulam were dose- and time-dependent (p<0.05) and caused a decreased on cell proliferation and the capacity clonogenic. The evaluation of gene expression in conditions of hypoxia (1%) compared to normoxia (preliminary experiments) showed increased expression to the genes CA9, CA12, HIF-1α and VEGF with decreased expression when the cells were treated with Indisulam. Conclusion: Our results indicate antiproliferative and inhibitory effect of the indisulam in GB cell line on condition of normoxic and hypoxic. It suggests that indisulam may be an interesting candidate for the development antitumor therapies based on the inhibition of tumor-associated carbonic anhydrase. Financial Support: FAPESP Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C292. Citation Format: Silvia A. Teixeira, Julia A. Pezuk, Maria S. Brassesco, Carlos G. Carlotti, Luiz G. Tone, Carlos A. Scrideli. Inhibition of carbonic anhydrase (9 and 12) decreases cell proliferation and gene expression in human glioblastoma cell. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C292.

Acquiring Metastatic Competence by Oral Squamous Cell Carcinoma Cells Is Associated with Differential Expression of α-Tubulin Isoforms.

We performed comparative global proteomics analyses of patient-matched primary (686Tu) and metastatic (686Ln) OSCC cells. The metastatic OSCC 686Ln cells showed greater in vitro migratory/invasive potential and distinct cell shape from their parental primary 686Tu cells. Ettan DIGE analysis revealed 1316 proteins spots in both cell lines with >85% to be quantitatively similar (<2 folds) between the two cell lines. However, two protein spots among four serial spots were highly dominant in 686Ln cells. Mass spectrometry sequencing demonstrated all four spots to be α-tubulin isotypes. Further analysis showed no significant quantitative difference in the α-tubulin between the two cell lines either at mRNA or protein levels. Thus, two distinct isoforms of α-tubulin, probably due to posttranslational modification, were associated with metastatic 686Ln cells. Immunofluorescence demonstrated remarkable differences in the cytosolic α-tubulin distribution patterns between the two cells. In 686Tu cells, α-tubulin proteins formed a normal network composed of filaments. In contrast, α-tubulin in 686Ln cells exhibited only partial cytoskeletal distribution with the majority of the protein diffusely distributed within the cytosol. Since α-tubulin is critical for cell shape and mobility, our finding suggests a role of α-tubulin isoforms in acquisition of metastatic phenotype and represents potential target for therapeutic intervention.

Proteasomal non‐catalytic subunit PSMD2 as a potential therapeutic target in association with various clinicopathologic features in lung adenocarcinomas

We previously identified PSMD2, a subunit of the 19S regulatory complex of proteasomes, as a constituent of a signature associated with the acquisition of metastatic phenotype and poor prognosis in lung cancers. In the present study, we found that knockdown of PSMD2 decreased proteasome activity, and induced growth inhibition and apoptosis in lung cancer cell lines. These effects of siRNA-mediated PSMD2 inhibition were associated with changes in the balance between phosphorylated AKT and p38, as well as with induction of p21. In addition, patients with higher PSMD2 expression had poorer prognosis and a small fraction of lung cancer specimens carried increased copies of PSMD2. Notably, our findings clearly illustrate that lung adenocarcinomas can be divided into two groups; those with and without general upregulation of proteasome pathway genes including PSMD2. This general upregulation was significantly more prevalent in the non-terminal respiratory unit (non-TRU)-type, a recently proposed genetically and clinicopathologically relevant expression profile-defined classification of adenocarcinomas (P < 0.001 by Fisher's exact test). Patients with adenocarcinomas with general upregulation had significantly shorter survival after potentially curative resection (P = 0.0001 by log-rank test) independent of disease stage, as shown by multivariate Cox regression analysis. Our results suggest that PSMD2 may be a good molecular target candidate and that other co-regulated proteasome pathway genes and/or their common regulator(s) might also be potential targets, warranting future study including elucidation of the underlying common regulatory mechanism.

Degradation of adhesion molecules of G361 melanoma cells by a non-thermal atmospheric pressure microplasma

Increased expression of integrins and focal adhesion kinase (FAK) is important for the survival, growth and metastasis of melanoma cells. Based on this well-established observation in oncology, we propose to use degradation of integrin and FAK proteins as a potential strategy for melanoma cancer therapy. A low-temperature radio-frequency atmospheric microplasma jet is used to study their effects on the adhesion molecules of G361 melanoma cells. Microplasma treatment is shown to (1) cause significant cell detachment from the bottom of microtiter plates coated with collagen, (2) induce the death of human melanoma cells, (3) inhibit the expression of integrin α2, integrin α4 and FAK on the cell surface and finally (4) change well-stretched actin filaments to a diffuse pattern. These results suggest that cold atmospheric pressure plasmas can strongly inhibit the adhesion of melanoma cells by reducing the activities of adhesion proteins such as integrins and FAK, key biomolecules that are known to be important in malignant transformation and acquisition of metastatic phenotypes.

Role of Transforming Growth Factor-β In Cancer Progression

Invasion and metastasis are the most lethal characteristics of cancer and the leading causes of cancer-related death. Transforming growth factor (TGF)-beta is a multifunctional cytokine that normally functions to prevent the uncontrolled proliferation of epithelial, endothelial and hematopoietic cells. Quite dichotomously, however, aberrant genetic or epigenetic events often negate the cytostatic function of TGF-beta in these cells, leading to tumor formation. Once freed from the growth-inhibitory effects of TGF-beta, cancer cells acquire the ability to proliferate, invade and metastasize when stimulated by TGF-beta. A thorough understanding of the molecular mechanisms underlying these paradoxical functions of TGF-beta remains elusive. Here, the authors review the tumor-suppressing and -promoting activities of TGF-beta and discuss the potential use and targeting of the TGF-beta-signaling system to prevent the progression and acquisition of metastatic phenotypes by human malignancies.

Involvement of reactive nitrogen oxides for acquisition of metastatic properties of benign tumors in a model of inflammation-based tumor progression

The cells of a weakly tumorigenic and non-metastatic murine fibrosarcoma (QR-32) are converted into highly malignant tumors (acquiring metastatic potential) once they have grown in vivo after being co-implanted with gelatin sponge which induces inflammation. In the present study, we examined whether nitric oxide (NO) is involved in the inflammation-based tumor progression by administrating a specific inhibitor to inducible nitric oxide synthase, aminoguanidine (AG). First, we co-implanted 1 x 10(5) QR-32 cells with gelatin sponge (10 x 5 x 3 mm piece) into a subcutaneous space in C57BL6 mice. Administration of AG in drinking water (1%) had started 2 days before the tumor implantation and continued until the termination of the experiment. The incidence of tumor formation and the tumor growth did not differ between AG-treated group and -untreated group. On day 28, we excised the arising tumors to establish culture cell lines for evaluation of their acquisition of metastatic phenotype in other normal mice. Metastasis incidence and the number of metastatic colonies were significantly reduced in the tumor cell lines obtained from AG-treated mice compared to those from non-treated mice (p < 0.05). Immunohistochemical analysis demonstrated that inducible nitric oxide synthase and nitrotyrosine in the inflamed lesion were reduced in the AG-administered mice. However, intensity of 8-hydroxy-2-deoxyguanosine was not different between the groups. These results showed that nitric oxide and its reactive nitrogen oxide species cooperatively play a pivotal role in the progression of benign tumor cells in inflamed lesions.

Loss of claudin‐1 expression in tumor‐associated vessels correlates with acquisition of metastatic phenotype in melanocytic neoplasms

Claudins are a family of transmembrane proteins involved in cell-to-cell adhesion and are believed to be the main component of tight junctions. Recent studies have suggested that some metastatic solid tumors lack claudin expression. It is unknown whether claudins play a role in cutaneous melanoma. Immunohistochemical studies were performed on tissue microarrays containing 19 benign melanocytic nevi (BN), 21 dysplastic nevi (DN), 23 primary malignant melanomas (MMs), and 31 metastatic melanomas (MMMs) using a polyclonal anti-claudin-1 antibody. Immunoreactivity in tumor cells and associated vessels was graded by intensity and by percentage of reactive cells. Normal epidermis served as internal control (3+ labeling). Cases with at least 2+ labeling in more than 25% of the cells were considered positive. Claudin-1 expression was present in 37% of BN, 24% of DN, 26% of MM, and 3.2% of MMM. Tumor-associated vessels showed the following results: 11 of 19 (58%) in BN, 14 of 21 (67%) in DN, 17 of 23 (74%) in MM, and 6 of 31 (19%) in MMM. A significant loss of expression was noted between MMM and all other lesions in tumor cells and associated vessels. There was no significant difference between BN, DN, and MM. Within primary melanomas, there was a significant correlation between expression of claudin in tumor cells and Clark level/Breslow thickness. Also significant was a decreased expression of claudin in tumor vessels of lesions with higher Breslow thickness or Clark level. These data suggest that loss of claudin-1 may play a significant role in the acquisition of metastatic phenotype in cutaneous melanoma. Cohn ML, Goncharuk VN, Diwan AH, Zhang PS, Shen SS, Prieto VG. Loss of claudin-1 expression in tumor-associated vessels correlates with acquisition of metastatic phenotype in melanocytic neoplasms.

A critical role of tropomyosins in TGF-beta regulation of the actin cytoskeleton and cell motility in epithelial cells.

We have investigated transforming growth factor beta (TGF-beta)-mediated induction of actin stress fibers in normal and metastatic epithelial cells. We found that stress fiber formation requires de novo protein synthesis, p38Mapk and Smad signaling. We show that TGF-beta via Smad and p38Mapk up-regulates expression of actin-binding proteins including high-molecular-weight tropomyosins, alpha-actinin and calponin h2. We demonstrate that, among these proteins, tropomyosins are both necessary and sufficient for TGF-beta induction of stress fibers. Silencing of tropomyosins with short interfering RNAs (siRNAs) blocks stress fiber assembly, whereas ectopic expression of tropomyosins results in stress fibers. Ectopic-expression and siRNA experiments show that Smads mediate induction of tropomyosins and stress fibers. Interestingly, TGF-beta induction of stress fibers was not accompanied by changes in the levels of cofilin phosphorylation. TGF-beta induction of tropomyosins and stress fibers are significantly inhibited by Ras-ERK signaling in metastatic breast cancer cells. Inhibition of the Ras-ERK pathway restores TGF-beta induction of tropomyosins and stress fibers and thereby reduces cell motility. These results suggest that induction of tropomyosins and stress fibers play an essential role in TGF-beta control of cell motility, and the loss of this TGF-beta response is a critical step in the acquisition of metastatic phenotype by tumor cells.

Genetic alterations responsible for metastatic phenotypes of lung cancer cells.

It is now widely accepted that human carcinogenesis is a multi-step process and phenotypic changes during cancer progression reflect the sequential accumulation of genetic alterations in cells. Thus, in order to understand the process of acquisition of metastatic phenotypes in cancer cells, it is indispensable to identify genes whose alterations accumulate during cancer progression and correlate with metastatic phenotypes of cancer cells. For this reason, we have been searching for genes that are preferentially altered in metastatic lung cancer cells and have activities to regulate their metastatic potentials. In lung cancer, both the p16INK4A/RB and p53 genes are frequently inactivated and are critical determinants for the regulation of cell growth and apoptosis. However, it still remains unclear whether these genes are also involved in the regulation of metastatic potential in lung cancer cells. Recently, we identified a novel myosin family gene, MYO18B, from the chromosome 22q12.1 region which shows frequent loss of heterozygosity in advanced lung cancer, and we found that this gene is inactivated in approximately 50% of lung cancers by deletions, mutations and methylation. Furthermore, restoration of MYO18B expression suppressed anchorage-independent growth of lung cancer cells. Thus, it was indicated that the MYO18B gene is a strong candidate for a metastasis suppressor gene of human lung cancer. Further functional and biological studies of the MYO18B gene will help us understand the molecular pathway of human lung cancer progression.

Significant up-regulation of a novel gene, CLCP1, in a highly metastatic lung cancer subline as well as in lung cancers in vivo.

Most lung cancer patients are unfortunately uncurable and die because of widespread metastases, thus indicating the importance of identification of molecules with a crucial role in this process. Our previous expression profiling analysis of a highly metastatic lung cancer cell line, NCI-H460-LNM35, and its parental low metastatic line, NCI-H460-N15, revealed significant up-regulation of both known and unknown genes in LNM35. In this study, we describe the isolation and detailed characterizations of a novel gene, named CLCP1, which corresponds to one of such expression sequence tags with up-regulated expression in LNM35. The CLCP1 gene was found to encode a protein with 775 amino acids with structural similarities to, but distinct from neuropilins, cell surface receptors for VEGF165 and semaphorins. Notably, CLCP1 was shown to be up-regulated not only in LNM35 in association with its acquisition of metastatic phenotype during in vivo selection, but also in a significant fraction of lung cancers in vivo with high frequency in metastatic lesions, warranting future studies for a better understanding of the molecular mechanisms of lung cancer metastasis.

Establishment of an in vitro cell model system to study human prostate carcinogenesis

A positive family history of prostate cancer is a risk factor for this disease, suggesting that alterations of certain genes may play an important role in the development and progression of prostate cancer. However, genetic alterations responsible for initiation and acquisition of metastatic phenotypes by prostate cancer are not well defined. We have observed a consistent change in chromosome 5 in an in vitro cell model of human prostate carcinogenesis in which the near-diploid cells from the surrounding tissue of an adenocarcinoma of the prostate obtained from a 42-year-old patient were subjected to in vitro cell culture and passages. We have examined three different passages of this cell strain by conventional and molecular cytogenetic methods and have seen an increased number of alterations in chromosome 5 in higher passage cells, with accompanying changes in cell morphology. In late passages of this cell line, no cell showed two normal copies of chromosome 5 as analyzed by G-banding and fluorecent in situ hybridization (FISH). The long arm (q) of chromosome 5 was either missing or involved in structural rearrangements. This observation suggests that the q arm of chromosome 5 may carry a tumor suppressor gene(s) that is well-expressed in normal prostate tissue, but when one of these tumor suppressor gene(s) is mutated or deleted and its encoded mRNA and protein are differentially expressed or not expressed at all in the prostate cells, then it may lead to initiation of tumor growth and development. Cytogenetic analyses of early passage cells in this cell strain revealed that approximately 78.8% of metaphases were normal, with a 46,XY chromosome constitution, and 21.2% of cells had clonal alterations mostly of chromosomes 5, 7, 8, 15, 16 and Y. In the middle passages, abnormal cells increased in number (78.26%) and also showed a large number of chromosomal changes. In the late passages, all cells showed structural and numerical abnormalities of the same chromosomes, in addition to some new markers; no cells were found to have a normal karyotype. These chromosomal aberrations could be considered early markers of prostate carcinogenesis. Some of the markers present in late passage cells were similar to those reported in a well-characterized prostate cancer cell line, LNCaP.