scholarly journals The Small G-Protein RalA Promotes Progression and Metastasis of Triple Negative Breast Cancer

Author(s):  
Katie A Thies ◽  
Matthew W. Cole ◽  
Rachel E Schafer ◽  
Jonathan M Spehar ◽  
Dillon S. Richardson ◽  
...  

Abstract Background: Breast cancer (BC) is the most common cancer in women and the leading cause of cancer-associated mortality in women. In particular, triple-negative BC (TNBC) has the highest rate of mortality due in large part to the lack of targeted treatment options for this subtype. Thus, there is an urgent need to identify new molecular targets for TNBC treatment. RALA and RALB are small GTPases implicated in growth and metastasis of a variety of cancers, although little is known of their roles in BC. Methods: The necessity of RALA and RALB for TNBC tumor growth and metastasis were evaluated in vivo using orthotopic and tail-vein models. In vitro, 2D and 3D cell culture methods were used to evaluate the contributions of RALA and RALB during TNBC cell migration, invasion, and viability. The association between TNBC patient outcome and RALA and RALB expression was examined using publicly available gene expression data and patient tissue microarrays. Finally, small molecule inhibition of RALA and RALB was evaluated as a potential treatment strategy for TNBC in cell line and patient-derived xenograft (PDX) models. Results: Knockout or depletion of RALA inhibited orthotopic primary tumor growth, spontaneous metastasis, and experimental metastasis of TNBC cells in vivo. Conversely, knockout of RALB increased TNBC growth and metastasis. In vitro, RALA and RALB had antagonistic effects on TNBC migration, invasion, and viability with RALA generally supporting and RALB opposing these processes. In BC patient populations, elevated RALA but not RALB expression is significantly associated with poor outcome across all BC subtypes and specifically within TNBC patient cohorts. Immunohistochemical staining for RALA in patient cohorts confirmed the prognostic significance of RALA within the general BC population and the TNBC population specifically. BQU57, a small molecule inhibitor of RALA and RALB, decreased TNBC cell line viability, sensitized cells to paclitaxel in vitro and decreased tumor growth and metastasis in TNBC cell line and PDX models in vivo. Conclusions: Together, these data demonstrate important but paradoxical roles for RALA and RALB in the pathogenesis of TNBC and advocate further investigation of RALA as a target for the precise treatment of metastatic TNBC.

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Katie A. Thies ◽  
Matthew W. Cole ◽  
Rachel E. Schafer ◽  
Jonathan M. Spehar ◽  
Dillon S. Richardson ◽  
...  

Abstract Background Breast cancer (BC) is the most common cancer in women and the leading cause of cancer-associated mortality in women. In particular, triple-negative BC (TNBC) has the highest rate of mortality due in large part to the lack of targeted treatment options for this subtype. Thus, there is an urgent need to identify new molecular targets for TNBC treatment. RALA and RALB are small GTPases implicated in growth and metastasis of a variety of cancers, although little is known of their roles in BC. Methods The necessity of RALA and RALB for TNBC tumor growth and metastasis were evaluated in vivo using orthotopic and tail-vein models. In vitro, 2D and 3D cell culture methods were used to evaluate the contributions of RALA and RALB during TNBC cell migration, invasion, and viability. The association between TNBC patient outcome and RALA and RALB expression was examined using publicly available gene expression data and patient tissue microarrays. Finally, small molecule inhibition of RALA and RALB was evaluated as a potential treatment strategy for TNBC in cell line and patient-derived xenograft (PDX) models. Results Knockout or depletion of RALA inhibited orthotopic primary tumor growth, spontaneous metastasis, and experimental metastasis of TNBC cells in vivo. Conversely, knockout of RALB increased TNBC growth and metastasis. In vitro, RALA and RALB had antagonistic effects on TNBC migration, invasion, and viability with RALA generally supporting and RALB opposing these processes. In BC patient populations, elevated RALA but not RALB expression is significantly associated with poor outcome across all BC subtypes and specifically within TNBC patient cohorts. Immunohistochemical staining for RALA in patient cohorts confirmed the prognostic significance of RALA within the general BC population and the TNBC population specifically. BQU57, a small molecule inhibitor of RALA and RALB, decreased TNBC cell line viability, sensitized cells to paclitaxel in vitro and decreased tumor growth and metastasis in TNBC cell line and PDX models in vivo. Conclusions Together, these data demonstrate important but paradoxical roles for RALA and RALB in the pathogenesis of TNBC and advocate further investigation of RALA as a target for the precise treatment of metastatic TNBC.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 619-619
Author(s):  
S. Seitz ◽  
A. V. Schally ◽  
S. Gluck ◽  
F. Rick ◽  
L. Szalontay ◽  
...  

619 Background: Triple negative breast cancers (TNBC) represent a distinct subtype of breast cancer being negative to ER, PR and HER2 and are associated with poor prognosis. Limited systemic treatment options exist for TNBC. TNBC cells express somatostatin receptors (SSTR). Therefore, to investigate preclinical characteristics of TNBC we used a novel targeted cytotoxic somatostatin analogue AN-162 containing doxorubicin (DOX) which binds to the subtypes 2, 3 and 5 of SSTR. Methods: The expression of SSTR in HCC 1806 human TNBC cell line was detected by RT-PCR. Cytotoxic effect of AN-162 in vitro was visualized by ethidium bromide staining fluorescence microscopy. Internalization of AN-162 into HCC 1806 cells was tested by 125Iodide-labeled AN-162 uptake assays and the presence of DOX in the nucleus was measured by fluorescence assays after separating the nucleus from the cytoplasm. For in vivo experiments, HCC 1806 TNBC cells were xenografted subcutaneously into nude mice which were then randomized into four groups receiving AN-162, DOX, an unconjugated mixture of DOX and somatostatin analogue RC-160 at the same equimolar dose of 2.5 μmol/kg (1.45 mg/kg Dox equivalent) i.v. (q7d 4x) and vehicle solution control. Results: HCC 1806 TNBC cell line was positive for the expression of all five SSTR receptor subtypes. Ethidum bromide staining of cells treated with 2.5 μM of AN-162 for 30 min demonstrated cell death after 24h by fluorescence microscopy. Uptake assays with AN-162 showed specific internalization of AN-162 into the cells mediated through the sstrs. After treatment of the cells with 2.5 μM AN-162 for 10 or 30 min, DOX could be detected in the nucleus by fluorescence assays. In vivo, AN-162 significantly (p<0.05) inhibited tumor growth of HCC 1806 xenografts compared to Control, DOX and the unconjugated mixture of DOX+RC-160 from day 14 and the inhibition remained significant until the end of the study on day 35. Conclusions: Our results indicate that treatment with targeted cytotoxic somatostatin analogue AN-162 produces a greater inhibition of tumor growth than DOX alone in somatostatin receptor positive TNBC. Our findings support the concept of targeted chemotherapy based on cytotoxic peptide analogues for the treatment of breast cancer and other cancers. No significant financial relationships to disclose.


2021 ◽  
Vol 9 (3) ◽  
pp. e001197
Author(s):  
Stanley Ly ◽  
Vivek Anand ◽  
Fouad El-Dana ◽  
Khoa Nguyen ◽  
Yiming Cai ◽  
...  

BackgroundTriple-negative breast cancer (TNBC) is the most aggressive breast cancer subtype with no effective standard therapy. Breast cancer stem-like cells (BCSCs) in primary TNBCs are reported to be responsible for metastatic spread of the disease and resistance to chemotherapy, but no available therapeutic tools target BCSCs. We previously reported that the ganglioside GD2 is highly expressed on BCSCs and that inhibition of its expression hampers TNBC growth. We therefore hypothesized that the anti-GD2 antibody dinutuximab (ch14.18) targets GD2+ BCSCs and inhibits TNBC growth.MethodTo test our hypothesis, we first determined GD2 expression via immunohistochemistry in frozen primary tumor samples from patients with TNBC (n=89). Then, we examined the effects of dinutuximab on TNBC cell adhesion, migration, and mammosphere formation in vitro and on tumor growth in vivo using TNBC cell-line and patient-derived xenograft (PDX) models.ResultsWe found that GD2 was expressed in around 60% of primary TNBC tumors at variable levels and was associated with worse overall survival of patients with TNBC (p=0.002). GD2 was found to be expressed in tumors and stroma, but normal ducts and lobules in adjacent tissues have shown low or no GD2 staining, indicating that GD2 is potentially a novel biomarker for tumor and its microenvironment. Treatment with dinutuximab significantly decreased adhesion and migration of MDA-MB-231 and SUM159 TNBC cells. Moreover, dinutuximab treatment inhibited mTOR signaling, which has been shown to be regulated by GD2 in BCSCs. Dinutuximab also reduced tumor growth in nude mice bearing TNBC cell-line xenografts. Finally, dinutuximab in combination with activated natural killer cells inhibited tumor growth in a TNBC PDX model and improved overall survival of tumor-bearing mice.ConclusionsDinutuximab successfully eliminated GD2+ cells and reduced tumor growth in both in vivo models. Our data provide proof-of-concept for the criticality of GD2 in BCSCs and demonstrate the potential of dinutuximab as a novel therapeutic approach for TNBC.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sofia M. Saraiva ◽  
Carlha Gutiérrez-Lovera ◽  
Jeannette Martínez-Val ◽  
Sainza Lores ◽  
Belén L. Bouzo ◽  
...  

AbstractTriple negative breast cancer (TNBC) is known for being very aggressive, heterogeneous and highly metastatic. The standard of care treatment is still chemotherapy, with adjacent toxicity and low efficacy, highlighting the need for alternative and more effective therapeutic strategies. Edelfosine, an alkyl-lysophospholipid, has proved to be a promising therapy for several cancer types, upon delivery in lipid nanoparticles. Therefore, the objective of this work was to explore the potential of edelfosine for the treatment of TNBC. Edelfosine nanoemulsions (ET-NEs) composed by edelfosine, Miglyol 812 and phosphatidylcholine as excipients, due to their good safety profile, presented an average size of about 120 nm and a neutral zeta potential, and were stable in biorelevant media. The ability of ET-NEs to interrupt tumor growth in TNBC was demonstrated both in vitro, using a highly aggressive and invasive TNBC cell line, and in vivo, using zebrafish embryos. Importantly, ET-NEs were able to penetrate through the skin barrier of MDA-MB 231 xenografted zebrafish embryos, into the yolk sac, leading to an effective decrease of highly aggressive and invasive tumoral cells’ proliferation. Altogether the results demonstrate the potential of ET-NEs for the development of new therapeutic approaches for TNBC.


2014 ◽  
Vol 8 (Suppl 4) ◽  
pp. P22
Author(s):  
Klesia Madeira ◽  
Murilo Cerri ◽  
Renata Daltoé ◽  
Alice Herlinger ◽  
João Filho ◽  
...  

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15047-e15047
Author(s):  
Surender Kharbanda ◽  
Anees Mohammad ◽  
Sachchidanand Tiwari ◽  
Neha Mehrotra ◽  
Sireesh Appajosyula ◽  
...  

e15047 Background: Triple negative breast cancer (TNBC) accounts for about 10-15% of all breast cancers and differ from other types of invasive breast cancers in that they grow and spread faster. TNBCs have limited treatment options and a worse prognosis. Therapy with anthracyclines considered to be one of the most effective agents in the treatment. Unfortunately, resistance to anthracycline therapy is very common due to drug efflux mediated by overexpression of ABC transporter. Pirarubicin (PIRA), an analogue of doxorubicin (DOX), is approved in Japan, Korea and China and is shown to be less cardiotoxic than DOX. Recent studies suggest that cancer stem cells (CSCs) play an important role in tumorigenesis and biology of TNBC. Targeting CSCs may be a promising, novel strategy for the treatment of this aggressive disease. Recent studies have shown that salinomycin (SAL) preferentially targets the viability of CSCs. Methods: SAL and PIRA were co-encapsulated in polylactic acid (PLA)-based block copolymeric nanoparticles (NPs) to efficiently co-deliver these agents to treat TNBC cells. Results: Generated SAL-PIRA co-encapsulated dual drug-loaded NPs showed an average diameter of 110 ± 7 nm, zeta potential of -12.5 mV and PDI of less than 0.25. Both of these anti-cancer agents showed slow and sustained release profile in non-physiological buffer (PBS, pH 7.4) from these dual drug-encapsulated NPs. Additionally, multiple ratios (PIRA:SAL = 3:1, 1:1, 1:3) were encapsulated to generate diverse dual drug-loaded NPs. The results demonstrate that, in contrast to 1:1 and 3:1, treatment of TNBC cells with 1:3 ratio of PIRA:SAL dual drug-loaded NPs, was associated with significant inhibition of growth in vitro in multiple TNBC cell lines. Interestingly, PIRA:SAL (1:3) was synergistic as compared to either SAL- or PIRA single drug-loaded NPs. The IC50 of PIRA and SAL in single drug-encapsulated NPs is 150 nM and 700 nM respectively in MDA-MB-468. Importantly, the IC50 of PIRA in dual drug-encapsulated NPs dropped down to 30 nM (5-fold). Similar results were obtained in SUM-149 TNBC cell line. Studies are underway to evaluate in vivo biological activity of PIRA:SAL (1:3) on tumor growth in a TNBC xenograft mice model. Conclusions: These results demonstrate that a novel dual drug-loaded NP formulation of PIRA and SAL in a unique ratio of 1:3 represents an approach for successful targeting of CSCs and bulk tumor cells in TNBC and potentially other cancer types.


2020 ◽  
Vol 318 (1) ◽  
pp. G10-G22
Author(s):  
Jun Zou ◽  
Kun Wu ◽  
Chao Lin ◽  
Zhi-Gang Jie

Gastric cancer (GC) is one of the most common cancers in the world and remains a heavy burden of health worldwide. Adenylate cyclase 3 ( ADCY3) is a widely expressed membrane-associated protein in human tissues and has been identified to be a new molecular target of GC. Long noncoding RNAs have a substantial influence on tumorigenesis and progression of tumors by binding to microRNAs. Therefore, this study is to clarify the mechanism by which LINC00319 sponges micro RNA-335–5p ( miR-335–5p) to influence the development of GC. Initially, microarray analysis identified GC-related differentially expressed LINC00319 and ADCY3 for this study. The interaction was confirmed that LINC00319 interacted with miR-335–5p to regulate ADCY3. Next, SGC-7901 cells presenting with the lowest LINC00319 expression and the highest miR-335–5p expression were transfected with LINC00319, miR-335–5p inhibitor, or ADCY3 vector to examine their roles in growth and metastasis of GC cells, which was further ascertained by in vivo experiments. LINC00319 was upregulated and miR-335–5p was downregulated in GC cells. LINC00319 overexpression, miR-335–5p inhibitor, or ADCY3 overexpression was shown to significantly elevate the expression of cyclin-dependent kinase 4 and metastasis associated 1, decrease that of growth arrest-specific 1, and promote tumor growth and metastasis by increasing proliferation and migration and reducing cell apoptosis. Importantly, it was found that overexpressed miR-335–5p exerted its tumor suppressive role in GC through downregulating ADCY3. Collectively, LINC00319 expedited growth and metastasis of GC by upregulating miR-335–5p-mediated ADCY3. NEW & NOTEWORTHY This study is carried out based on in vivo and in vitro studies in mice and gastric cancer (GC) cells with the aim of clarifying the role of LINC00319 on GC growth and metastasis, which associated with micro RNA-335–5p-mediated adenylate cyclase 3. Altogether, we identified LINC00319 to be a potential therapy to treat GC.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Fu-Tao Chen ◽  
Fu-Kuan Zhong

Objective. To determine the expression levels of KIF18A in lung adenocarcinoma and its relationship with the clinicopathologic features of patients undergoing radical colectomy and explore the potential role in the progression of lung adenocarcinoma. Methods. Immunohistochemical assays were performed to explore the expression levels of KIF18A in 82 samples of lung adenocarcinoma and corresponding normal tissues. According to the levels of KIF18A expression in lung adenocarcinoma tissue samples, patients were classified into the KIF18A high expression group and low expression group. Clinical data related to the perioperative clinical features (age, gender, smoking, tumor size, differentiation, clinical stage, and lymph node metastasis), the potential correlation between KIF18A expression levels, and clinical features were analyzed, and the effects of KIF18A on lung adenocarcinoma cell proliferation, migration, and invasion were measured by colony formation assay, MTT assay, wound healing assay, and transwell assays. The possible effects of KIF18A on tumor growth and metastasis were measured in mice through tumor growth and tumor metastasis assays in vivo. Results. KIF18A in lung adenocarcinoma tissues. Further, KIF18A was significantly associated to clinical characteristic features including the tumor size (P=0.033) and clinical stage (P=0.041) of patients with lung adenocarcinoma. Our data also investigated that KIF18A depletion dramatically impairs the proliferation, migration, and invasion capacity of lung adenocarcinoma cells in vitro and inhibits tumor growth and metastasis in mice. Conclusions. Our study reveals the involvement of KIF18A in the progression and metastasis of lung adenocarcinoma and provides a novel therapeutic target for the treatment of lung adenocarcinoma.


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