MACC1 Expression Research Articles

MACC1 knockdown enhances RSL3-induced ferroptosis in human colorectal cancer cells by inhibiting GPX4 expression

To investigate the effect of MACC1 on RSL3-induced ferroptosis in colorectal cancer cells and explore its molecular mechanism. MACC1 expression was detected in SW620, HCT116, LOVO and RKO cells using Western blotting. The effects of different concentrations of RSL3 (an inducer of ferroptosis) or Fer-1 (an inhibitor of ferroptosis) alone, or 10 μmol/L RLS3 combined with 10 μmol/L Fer-1, on viability of SW620 cells were examined using MTT assay. The survival of SW620 cells with mRNA interference of MACC1 was analyzed following treatment with RSL3, and RT-qPCR and Western blotting were performed to detect the changes in MACC1 expressions after RSL3 treatment at different concentrations and the changes in GPX4 expression after MACC1 knockdown. Flow cytometry and laser confocal microscopy were used to analyze the changes in ROS-induced lipid peroxidation in SW620 cells after MACC1 knockdown. SW620 cells had the highest MACC1 expression among the 4 colorectal cancer cell lines. Treatment with RSL3 significantly inhibited the viability of SW620 cells in a dose-dependent manner, while Fer-1 did not significantly affect the survival of SW620 cells. RSL3 alone reduced SW620 cell survival by 50% (P < 0.01), and the combined treatment with RSL3 and Fer-1 caused no significant changes in cell survival (P > 0.05). Treatment with RSL3 concentration-dependently suppressed MACC1 expressions at both the mRNA and protein levels in SW620 cells (P < 0.01). MACC1 knockdown obviously enhanced the cytotoxic effect of RSL3, inhibited the expression of GPX4, and increased ROS-induced lipid peroxidation in SW620 cells (P < 0.05). MACC1 knockdown enhances RSL3-induced ferroptosis in cultured colorectal cancer cells by inhibiting the expression of GPX4.

Saikosaponin-b2 Regulates the Proliferation and Apoptosis of Liver Cancer Cells by Targeting the MACC1/c-Met/Akt Signalling Pathway.

Saikosaponin-b2 (SS-b2), an active ingredient derived from the root of Radix Bupleuri, possesses antitumour, anti-inflammatory, antioxidative and hepatoprotective properties. We investigated the inhibition of tumour proliferation by SS-b2 and the underlying molecular mechanisms, including the MACC1/p-c-Met/p-Akt pathway expression in HepG2 liver cancer cells and H22 tumour-bearing mice. Animal experiments showed that SS-b2 significantly decreased the levels of MACC1, p-c-MET and p-Akt in tumour tissue transplanted with H22 liver cancer cells in mice, while it increased the expression of p-BAD. The results also revealed a concentration-dependent suppression of MACC1, p-c-Met and p-Akt expression in the SS-b2 treatment group compared with the control group. Additionally, the suppression of MACC1 activation by SS-b2 resulted in a reduction in the viability and proliferation of HepG2 liver cancer cells, and this reduction was comparable to that by doxorubicin (DOX). This suggests that SS-b2 has significant efficacy in liver cancer, comparable to DOX. Meanwhile, Annexin V-FITC/PI staining and western blot analysis of cleaved caspase 9 and cleaved caspase 3 demonstrated that SS-b2 induced apoptosis of HepG2 liver cancer cells. These findings provide experimental evidence suggesting that SS-b2 is a promising anticancer agent for liver cancer.

GIPC1 regulates MACC1-driven metastasis.

Identification of cancer metastasis-relevant molecular networks is desired to provide the basis for understanding and developing intervention strategies. Here we address the role of GIPC1 in the process of MACC1-driven metastasis. MACC1 is a prognostic indicator for patient metastasis formation and metastasis-free survival. MACC1 controls gene transcription, promotes motility, invasion and proliferation of colon cancer cells in vitro, and causes tumor growth and metastasis in mice. By using yeast-two-hybrid assay, mass spectrometry, co-immunoprecipitation and peptide array we analyzed GIPC1 protein binding partners, by using the MACC1 gene promoter and chromatin immunoprecipitation and electrophoretic mobility shift assay we probed for GIPC1 as transcription factor. We employed GIPC1/MACC1-manipulated cell lines for in vitro and in vivo analyses, and we probed the GIPC1/MACC1 impact using human primary colorectal cancer (CRC) tissue. We identified MACC1 and its paralogue SH3BP4 as protein binding partners of the protein GIPC1, and we also demonstrated the binding of GIPC1 as transcription factor to the MACC1 promoter (TSS to -60 bp). GIPC1 knockdown reduced endogenous, but not CMV promoter-driven MACC1 expression, and diminished MACC1-induced cell migration and invasion. GIPC1 suppression reduced tumor growth and metastasis in mice intrasplenically transplanted with MACC1-overexpressing CRC cells. In human primary CRC specimens, GIPC1 correlates with MACC1 expression and is of prognostic value for metastasis formation and metastasis-free survival. Combination of MACC1 and GIPC1 expression improved patient survival prognosis, whereas SH3BP4 expression did not show any prognostic value. We identified an important, dual function of GIPC1 - as protein interaction partner and as transcription factor of MACC1 - for tumor progression and cancer metastasis.

Correlation between the expressions of metastasis-associated factor-1 in colon cancer and vacuolar ATP synthase.

Clinical prognosis often worsens due to high recurrence rates following radical surgery for colon cancer. The examination of high-risk recurrence factors post-surgery provides critical insights for disease evaluation and treatment planning. To explore the relationship between metastasis-associated factor-1 in colon cancer (MACC1) and vacuolar ATP synthase (V-ATPase) expression in colon cancer tissues, and recurrence rate in patients undergoing radical colon cancer surgery. We selected 104 patients treated with radical colon cancer surgery at our hospital from January 2018 to June 2021. Immunohistochemical staining was utilized to assess the expression levels of MACC1 and V-ATPase in these patients. The rates of MACC1 and V-ATPase positivity were 64.42% and 67.31%, respectively, in colon cancer tissues, which were significantly higher than in paracancerous tissues (P < 0.05). Among patients with TNM stage III, medium to low differentiation, and lymph node metastasis, the positive rates of MACC1 and V-ATPase were significantly elevated in comparison to patients with TNM stage I-II, high differentiation, and no lymph node metastasis (P < 0.05). The rate of MACC1 positivity was 76.67% in patients with tumor diameters > 5 cm, notably higher than in patients with tumor diameters ≤ 5 cm (P < 0.05). We observed a positive correlation between MACC1 and V-ATPase expression (rs = 0.797, P < 0.05). The positive rates of MACC1 and V-ATPase were significantly higher in patients with recurrence compared to those without (P < 0.05). Logistic regression analysis revealed TNM stage, lymph node metastasis, MACC1 expression, and V-ATPase expression as risk factors for postoperative colon cancer recurrence (OR = 6.322, 3.435, 2.683, and 2.421; P < 0.05). The upregulated expression of MACC1 and V-ATPase in colon cancer patients appears to correlate with clinicopathological features and post-radical surgery recurrence.

Discovery of tetrazolo-pyridazine-based small molecules as inhibitors of MACC1-driven cancer metastasis

Metastasis is directly linked to poor prognosis of cancer patients and warrants search for effective anti-metastatic drugs. MACC1 is a causal key molecule for metastasis. High MACC1 expression is prognostic for metastasis and poor survival. Here, we developed novel small molecule inhibitors targeting MACC1 expression to impede metastasis formation. We performed a human MACC1 promoter-driven luciferase reporter-based high-throughput screen (HTS; 118.500 compound library) to identify MACC1 transcriptional inhibitors. HTS revealed 1,2,3,4-tetrazolo[1,5-b]pyridazine-based compounds as efficient transcriptional inhibitors of MACC1 expression, able to decrease MACC1-induced cancer cell motility in vitro. Structure-activity relationships identified the essential inhibitory core structure. Best candidates were evaluated for metastasis inhibition in xenografted mouse models demonstrating metastasis restriction. ADMET showed high drug-likeness of these new candidates for cancer therapy. The NFκB pathway was identified as one mode of action targeted by these compounds. Taken together, 1,2,3,4-tetrazolo[1,5-b]pyridazine-based compounds are effective MACC1 inhibitors and pose promising candidates for anti-metastatic therapies particularly for patients with MACC1-overexpressing cancers, that are at high risk to develop metastases. Although further preclinical and clinical development is necessary, these compounds represent important building blocks for an individualized anti-metastatic therapy for solid cancers.

Long Intergenic Non-Coding RNA LINC00885 Promotes Tumorigenesis of Cervical Cancer by Upregulating MACC1 Expression Through Serving as a Competitive Endogenous RNA for microRNA-432-5p [Retraction

[This retracts the article DOI: 10.2147/CMAR.S291778.].

MACC1 and MET as markers associated with progression and metastasis in cutaneous melanoma.

Cutaneous melanoma is the most common lethal malignancy among skin cancers and has a high propensity for metastasis. Understanding the mechanisms governing tumorigenesis, progression and metastasis as well as identifying biomarkers guiding risk stratification and management of the disease is essential. MACC1 has been found to play key roles in cancer cell migration, invasion, epithelial-to-mesenchymal transition, and metastasis in various types of cancer, through activation of MET signaling. In this study, we examined the extent of MACC1 and MET protein expression by immunohistochemical staining in a tissue microarray constructed from twenty-three melanomas and ten melanocytic nevi. We observed significantly higher levels of MACC1 expression on average in metastatic melanomas, comparing to primary melanomas and nevi. MET expression in metastatic melanomas was also significantly higher than in nevi. MACC1 expression does not appear to correlate with MET expression in nevi and primary melanomas. However, this correlation appears stronger in metastatic melanomas, where seven (78%) of nine cases show intermediate to high expression of both MACC1 and MET. The expressions of MACC1 and MET do not show significant differences based on other clinicopathologic factors including patient age, gender, histologic subtypes, depth of invasion, and staging. Our study suggests that high expression of MACC1 or both MACC1 and MET is associated with metastasis of cutaneous melanoma.

Long non-coding FAM201A accelerates the tumorigenesis and progression of colorectal cancer through miR-3163/MACC1 axis

Colorectal cancer (CRC) is the leading contributor to cancer-relevant deaths worldwide with severe incidence and mortality. An extensive body of evidence has demonstrated that lncRNA plays a critical role in the oncogenicity of CRC. Despite the oncogenic function of FAM201A in esophageal squamous cell cancer and non-small-cell lung cancer, the potential of FAM201A in CRC progression remains unknown. FAM201A expression level was significantly enhanced in CRC cells compared with normal cells. Further, functional experiments illustrated that knockdown of FAM201A restrained cell growth, stemness and promoted chemoresistance of CRC cells. By exploring molecular mechanism of FAM201A, we found that FAM201A acted as a sponge of miR-3163. More importantly, oncogene MACC1 was confirmed to be a direct target of miR-3163 and FAM201A modulated MACC1 expression level via competing for miR-3163. Subsequently, we testified that FAM201A exerted its role in the tumorigenesis and development of CRC through targeting miR-3163/MACC1. Animal assay certified that FAM201A expedited CRC cell growth in vivo. In conclusion, our study was the first to unveil that FAM201A promoted cell proliferation and CSC characteristics in CRC via regulation of the miR-3163/MACC1 axis, which provided clues for the clinical treatment of patients with this disease.

Long Intergenic Non-Coding RNA LINC00885 Promotes Tumorigenesis of Cervical Cancer by Upregulating MACC1 Expression Through Serving as a Competitive Endogenous RNA for microRNA-432-5p [Expression of Concern

Expression of Concern for the article Long Intergenic Non-Coding RNA LINC00885 Promotes Tumorigenesis of Cervical Cancer by Upregulating MACC1 Expression Through Serving as a Competitive Endogenous RNA for microRNA-432-5p

MACC1 Promotes the Progression and Is a Novel Biomarker for Predicting Immunotherapy Response in Colorectal Cancer.

Aims As one of the most prevalent malignant diseases in the world, the mechanisms of metastasis in colon cancer are poorly understood. The aim of this study was to investigate the role of the HGF/c-MET axis in the proliferation and metastasis in colon cancer. Methods The effect of MACC1 on cell proliferation and metastasis was analyzed through a series of in vitro experiments. The role of MACC1 in cancer cells was demonstrated by overexpression and silencing of MACC1 in gain or loss function experiments. To investigate the relationship between MACC1 and c-MET/HGF, we detected c-MET protein expression by disrupting with or overexpressing MACC1. The bioinformatics analysis was used to investigate the correlation between MACC1 and c-MET, and the c-MET expression after the interference of HGF with MACC1 was determined. Subsequently, the function of c-MET was verified in colon cancer cells by a series of experiments. The mouse tumor transplantation model experiment is most suitable in vivo. Results The results indicated that the overexpression of MACC1 could accelerate proliferation and facilitate metastasis in colon cancer cell lines. Furthermore, c-MET was determined to be the downstream regulator of MACC1. The addition of HGF could stimulate the expression of MACC1. With further exploration, we proved that c-MET is downstream of MACC1 in colon cancer and that overexpression of c-MET in colon cancer enhances cell proliferation and migration capability. At last, MACC1 expression level negatively correlates with the infiltration levels and several immune checkpoint biomarkers. High MACC1 expression has a lower response rate with ICIs in COAD. Conclusions We found that, under the regulation of the MACC1/HGF/c-MET axis, the proliferation and metastasis of colorectal cancer are increased by MACC1, which can be a novel biomarker for predicting ICIs response in colorectal cancer. Our findings provide a new idea for the targeted treatment of colorectal cancer.

Hsa_circ_0005100 regulates tumorigenicity of colorectal carcinoma via miR-145-5p/MACC1 axis.

BackgroundCircular RNAs (circRNAs) are a kind of RNA molecules involved in the regulation of cancer progression, including colorectal carcinoma (CRC); nevertheless, their regulation mode is blurry. In the present work, we attempted to reveal the characteristics of hsa_hsa_circ_0005100 in CRC.MethodsDifferential expressions of hsa_circ_0005100, FMN2 mRNA, microRNA‐145‐5p (miR‐145‐5p), and MACC1 were indicated by qRT‐PCR and Western blot. The capacities of cell growth and motility were validated by the MTT assay, flow cytometry assay, EdU assay, colony formation assay, and transwell assay. Moreover, the targeted relationship of miR‐145‐5p and hsa_circ_0005100 or MACC1 was distinguished by dual‐luciferase reporter assay. The animal experiment was implemented to confirm the influence of hsa_circ_0005100 on tumorigenesis in vivo.ResultsHsa_circ_0005100 and MACC1 expression levels were increased, but miR‐145‐5p expression level was diminished in CRC. Hsa_circ_0005100 knockdown repressed cell proliferation, cell cycle, migration, and invasion, while expedited cell apoptosis in CRC cells. Furthermore, miR‐145‐5p was disclosed to block CRC via overturning MACC1. Hsa_circ_0005100 targeted miR‐145‐5p to modulate MACC1. Additionally, hsa_circ_0005100 knockdown also attenuated tumorigenesis in vivo.ConclusionHsa_circ_0005100 was a vital regulator in the development of CRC by miR‐145‐5p/MACC1 axis, which deepened the understanding of CRC pathogenesis from circRNA insights.

The Relationship between MACC1/c-Met/Cyclin D1 Axis Expression and Prognosis in ESCC.

Background Esophageal cancer is one of the most common malignant tumors of the digestive system, with high incidence and mortality. Methods Immunohistochemical method was used to detect the expression of MACC1, c-Met, and cyclin D1 in ESCC and its adjacent tissues. Statistical analysis was done by SPSS 23.0. Results The high expression of MACC1 and cyclin D1 was significantly correlated with tumor size. High c-Met expression was associated with patient ethnicity. MACC1 expression was positively correlated with both c-Met and cyclin D1. c-Met expression was also positively correlated with cyclin D1. Patients with high expression of MACC1 and c-Met had worse OS; patients with high c-Met expression also had worse PFS. Conclusion MACC1, c-Met, and cyclin D1 proteins are closely related to the occurrence and development of esophageal squamous cell carcinoma. MACC1 may affect the prognosis of ESCC by regulating the expression of the c-Met/cyclin D1 axis.

Association of MACC1 expression with lymphatic metastasis in colorectal cancer: A nested case-control study.

MACC1 gene is a newly discovered gene and plays an important role in the metastasis of colorectal cancer (CRC). The objective of this study was to investigate whether MACC1 is an independent factor associated with lymphatic metastasis in CRC patients. We analyzed the association between MACC1 expression and lymphatic metastasis in a nested case-control study including 99 cases and 198 matched controls in CRC patients, assessed from August 2001 to March 2015. Cases were defined as lymphatic metastasis and non-lymphatic metastasis according to AJCC TNM stages; for each case, two age-matched control without lymphatic and distant metastasis was randomly selected from the study participants. Demographic, variables about metastasis and MACC1 expression were collected. In multivariate analysis, the OR (95% CI) of MACC1 expression was 1.5 (1.1 to 2.0) in patients with lymphatic metastasis versus non-lymphatic metastasis after adjusting all variables. After adjustment for all variables and age stratification, MACC1 expression was found to be an independent risk factor for lymph node metastasis in the middle-aged group (OR 2.1, 95%CI 1.1-4.0). A nonlinear relationship between MACC1 expression and 64-75 age group was observed. The probability of metastasis slightly increased with the MACC1 level lower than turning point 1.4. At the same time, the probability of lymphatic metastasis was obviously increased even after adjusting all variables when MACC1 level higher than 1.4 (OR 11.2, 95% CI 1.5-81.5; p = 0.017) in the middle age group. The expression of MACC1 was not associated with lymphatic metastasis in populations younger than 64 or older than 75. The results demonstrates that increased MACC1 level in 64-75 age group might be associated with lymphatic metastasis in CRC patients.

Abstract 2879: MACC1 overexpression in colorectal cancer is driven by chromosomal instability and is associated with molecular subtype

Abstract Metastasis-Associated in Colon Cancer 1 (MACC1) is a strong prognostic marker for human colorectal cancers (CRC). The gene is a key regulator of the HGF/c-Met pathway and its overexpression is associated with cancer cell proliferation, migration, invasiveness and metastasis. The contexture of MACC1 overexpression in cancers is still poorly understood. Here we used the data released by The Cancer Genome Atlas (TCGA) and in silico approaches for a deep and integrative analysis of MACC1 expression modalities in CRCs. First, we curated COAD-READ TCGA datasets and obtained full clinical, genomic, and transcriptomic annotation for a total of 259 CRC samples. In tumors, we showed high heterogeneity of MACC1 mRNA expression levels with data varying from 5.58 to 13.07 U (RNAseq log transformed data - RSEM normalized). By correlating MACC1 expression to clinical data, we showed its levels were associated with anatomic regions of the disease (p=6.35.10-5). The tumors from descending colon and rectum having higher levels than those of the ascending colon and caecum (p=7.44-06). High MACC1 was also associated with higher tumor stages (p=0.01) and nodal invasion (p=0.03). At genomic level, MACC1 mutation was not frequent in CRCs (&amp;lt;2%). The gene is however frequently subjected to gene copy number variation (CNV) due to chromosomal instability and polyploidy (MACC1 CNV values &amp;gt; normal in 155/259: 60%). Correlation analysis indicated strong positive association between MACC1 copy number variations and mRNA expression levels (p&amp;lt;10-16). In an independent dataset, we validate that gain of MACC1 gene copy number and associated higher expression levels correlated with metastasis dissemination and worse outcome of the patients. By analyzing MACC1 with respect of CRC subtypes, we confirmed higher MACC1 levels in MSS tumors with high chromosomal instability (CIN) compared to MSI or genomic stable tumors (GS) (p=1.16-14). Regarding association with CMS1-4 transcriptomic subtypes, the highest expression of MACC1 were observed in CMS2-(epithelial), and CMS4 (mesenchymal) as compared with CMS3 (epithelial with metabolic dysregulation) or CMS1 (MMR deficient). The subset of tumors with very low MACC1 expression were mainly those altered for MLH1 (MSI-H- MMR tumors), notably most of them have normal ploidy. Deconvolution analysis of immune contexture revealed negative correlation between MACC1 expression and immune activation. Stratification using MACC1 as prognostic marker within these tumor types will be evaluated and the gene will also be presented with respect of alterations of key cancer genes in these tumors. Overall, the present study gives insight into the contexture of MACC1 expression in CRC. We showed MACC1 overexpression is largely driven by chromosomal instability and DNA copy number gains. Its expression was dependent on the tumor molecular subtypes. Citation Format: Vincent Vuaroqueaux, Hoor Al-Hasani, Dennis Kobelt, Thomas Risch, Susen Burock, Marie-Laure Yaspo, Heinz-Herbert Fiebig, Ulrike Stein. MACC1 overexpression in colorectal cancer is driven by chromosomal instability and is associated with molecular subtype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2879.

LncRNA FGD5-AS1 Facilitates the Radioresistance of Breast Cancer Cells by Enhancing MACC1 Expression Through Competitively Sponging miR-497-5p.

BackgroundLncRNA-FGD5-AS1, as an oncogene, participates in the development and progress of various cancers. However, the exact role and the molecular mechanisms by which FGD5-AS1 regulates radiosensitivity in breast cancer (BC) remains largely unknown.MethodsWe used X-Ray weekly-dose-increase method to establish radiation-resistance cell lines. Bioinformatics tools analyze the expression of FGD5-AS1 in breast cancer tissue and evaluated the relationship between FGD5-AS1 and clinic-pathological features. CCK-8 and colony formation were used to analyze cell proliferation. Western blotting and qPCR were applied to detect protein and gene expression, respectively. RNA interference was used to knock down the endogenous gene expression. Luciferase reporter system and immunoprecipitates were applied to verify the target of FGD5-AS1.ResultFGD5-AS1 was overexpressed in BC tissues and radiation-resistance cell lines. Higher levels of FGD5-AS1 predicted poorer clinical characteristics and prognosis. Loss-of-function FGD5-AS1 sensitized BC cells to X-ray, meanwhile, the cell gained radiation-resistance when exogenous FGD5-AS1 was expressed. FGD5-AS1 depletion arrested cells at G0/G1 and triggers cell apoptosis. The starBase database (ENCORI), predicted binding site of miR-497-5p in FGD5-AS1 sequence, and luciferase reporter system and immunoprecipitates verified miR-497-5p was the target of FGD5-AS1. Furthermore, MACC1 was predicted and verified as the target of miR-497-5p. Loss-of-function FGD5-AS1 sensitized ionizing radiation was rescued by the up-regulation of MACC1 and the inhibition of miR-497.ConclusionFGD5-AS1 displays an oncogene profile in CRC; patients with high expression of FGD5-AS1 should benefit less from radiotherapy and need a more frequent follow-up. Besides, FGD5-AS1 may be a potential therapeutic target for CRC.

Abstract B14: Activation of the MACC1/PIM/cMyc axis confers resistance to PI3K/mTOR inhibition in PIK3CA mutant NSCLC

Abstract Introduction: The PI3K pathway is often dysregulated in lung cancer, making it an ideal therapeutic target. Pan- and isoform-specific inhibitors of the PI3K pathway are currently being evaluated in clinical trials. However, all patients treated thus far develop progressive disease due to the emergence of bypass signaling mechanisms. We developed a panel of lung cancer preclinical models to elucidate potential mechanisms of resistance to PI3K-mTOR inhibitor GDC-0980 (apitolisib). In-depth characterization of the PIK3CA mutant positive H1975 sensitive cells (H1975P) versus apitolisib-resistant cells (H1975GR) identified activation of MACC1 as an early marker of drug resistance and the subsequent activation of all three PIM kinases. Inhibition of MACC1 and PIM kinase by siRNAs and the effect of IBL-301 (a novel PIM/PI3K/mTOR inhibitor) were examined for effects on cell viability/proliferation and downstream signaling pathways in vitro. Methods: Profiling of H1975P versus H1975GR cells was undertaken using a mRNA/lncRNA array (Arraystar Inc) to quantify the expression of 20,730 mRNAs and 40,173 lncRNAs. Concomitant changes were assessed in the IL6/STAT3 signaling pathway by a QPCR array, immunofluorescence, Western blot and miRNA arrays. The effect of MACC1 and PIM kinase inhibition by siRNAs and targeted agents were examined by Western blot and cell viability assays. Results: MACC1 mRNA was upregulated 77 fold in H1975GR cells after 1-month exposure to apitolisib, and its regulated proteins HGF and MET were upregulated (10.06 and 1.65 fold, respectively). At 4 months MACC1 mRNA was increased by 44 fold, HGF 2 fold and MET 6.6 fold while several members of the IL-6/STAT3 pathway including c-Myc and PIM1, PIM2 and PIM3 kinases were also significantly activated (25.5, 19.8, 3.3 and 31.9 fold respectively). Results were also validated by Western blot. A miRNA signature of PI3K/mTOR inhibitor resistance was validated that can be used to monitor patients on treatment. Inhibition of PIM kinases by siRNA and targeted therapy restored sensitivity to PI3K-mTOR inhibitors. Novel triple-targeted therapy IBL-301 decreased PIM kinase, c-Myc and MACC1 expression. IC50 values of IBL-301 were significantly less for H1975GR cells (0.02μM) compared to H1975P cells (0.75μM), highlighting activated PIM kinase as a mechanism of resistance to PI3K-mTOR inhibition. Conclusion: Activated MACC1, PIM kinases and their interacting partners play a role in resistance to PI3K-mTOR inhibitors in PIK3CA mutant NSCLC. Our data provide a rationale for combined or sequential targeting of PI3K-mTOR and PIM kinases to significantly delay resistance and provide durable treatment responses in patients with PIK3CA mutant lung tumors. Citation Format: Gillian Moore, Samira Elbai, Susan Heavey, Stephen Finn, Michael O'Neill, Kathy Gately. Activation of the MACC1/PIM/cMyc axis confers resistance to PI3K/mTOR inhibition in PIK3CA mutant NSCLC [abstract]. In: Proceedings of the AACR Special Conference on Targeting PI3K/mTOR Signaling; 2018 Nov 30-Dec 8; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(10_Suppl):Abstract nr B14.

RETRACTED ARTICLE: A novel small-molecule inhibitor suppresses colon cancer metastasis through inhibition of metastasis-associated in colon cancer-1 transcription.

We previously reported that the metastasis-associated in colon cancer-1 (MACC-D1) is overexpressed in colon cancer. However, so far, only a few effective MACC-1 inhibitors have been identified. To discover novel transcriptional inhibitors of MACC-1, we performed a luciferase reporter-based high-throughput screening (HTS). This strategy discovered rottlerin as an inhibitor of MACC-1 transcription was able to reduce cell motility in colon cancer in time- and dose-dependent manners. Wound healing assay indicated that 48-h treatment with 2.5 μM rottlerin impairs wound closure compared to the controls. Electrophoretic mobility shift assays showed that rottlerin inhibits the binding of the transcriptional activators Sp1 and c-Jun with human MACC-1 promoter. A combination of Western blot assays and expression analyses by qRT-PCR ruled out that rottlerin may act indirectly through inhibition of c-Jun or Sp1 expression to decrease MACC-1 expression in human colon cancer cell lines SW620. Rather, these results support that rottlerin restricts the binding of MACC-1 promoter directly by c-Jun and Sp1 in colon cancer cells. Thus, as a small-molecule inhibitor of MACC-1, rottlerin may benefit colon cancer patients by suppressing MACC-1-dependent tumor growth and metastasis.

Restoring Treatment Response in Colorectal Cancer Cells by Targeting MACC1-Dependent ABCB1 Expression in Combination Therapy.

Treatment failure of solid cancers, represented by the development of drug resistance in the primary tumor or later outgrowth of drug resistant metastases, is the major cause of death for cancer patients. It represents an urgent clinical need for predictive biomarkers which indicate the success or failure of standard treatment regimens. Besides treatment prediction, interfering with cellular processes associated with drug resistance might improve treatment response by applying combination therapies. Metastasis-associated in colon cancer (MACC) 1 was identified in our group as a prognostic biomarker in human colorectal cancer, and has been established as key player, prognostic, and predictive biomarker for tumor progression and metastasis in a variety of solid cancers. Besides increased cell proliferation and motility, subsequently contributing to growth and metastatic spread of the primary tumor, MACC1 has also been shown to dysregulate apoptosis and is contributing to treatment resistance. Here we report the MACC1 dependent treatment resistance of colorectal cancer (CRC) cells to standard therapeutics like doxorubicin by upregulating ATP-binding cassette subfamily B member 1 (ABCB1) protein. Overexpression of MACC1 in CRC cells increased both its presence on the ABCB1 promoter and its transcriptional activity, resulting in elevated ABCB1 expression and thus treatment resistance to standard therapeutics. In contrast, depleting MACC1 increased intracellular drug concentrations, leading to better treatment response. We already identified the first MACC1 transcriptional inhibitors, such as lovastatin, by high-throughput screening of clinically approved small molecule drugs. These compounds inhibited cell motility in vitro but also restricted metastasis development in xenograft mouse models by reducing MACC1 expression. Here we report, that treating high MACC1 expressing CRC cells with a combination of statins and standard therapeutics increased the rate of cytotoxicity and resulted in higher treatment response.

MACC1 expression is an indicator of recurrence in early-stage glottic cancer.

Metastasis-associated in colon cancer 1 (MACC1) has been reported to be an independent indicator of poor prognoses in some kinds of cancer due to disease metastasis or recurrence. We investigated the correlation between MACC1 expression and the prognosis of glottic cancer. Paraffin-embedded, early-stage (I or II) glottic cancer specimens (n=52) were immunohistochemically analyzed to explore MACC1 expression. The clinical records associated with each case were also examined. Recurrence-free survival (RFS) was estimated using the Kaplan-Meier method, and between-group RFS differences were assessed using the log-rank test. The multivariate analyses were evaluated using the Cox's proportional-hazard model. Patients were treated with only radiotherapy (RT) (n=37, including 18 with T1 disease and 19 with T2 disease), or with chemoradiotherapy (CRT) (n=15, including 1 with T1 disease and 14 with T2 disease). Eleven patients demonstrated local recurrence and two patients experienced cervical lymph node recurrence. Tumor specimens were MACC1-positive in 9 of the 13 (69.2%) patients with local or neck recurrence, and 7 of the 11 (63.6%) patients with local recurrence. The RFS rate of patients who were treated with only RT was significantly lower than that of patients who were treated with CRT (P=0.0243). The RFS rate was significantly lower in cases with MACC1 expression than in those without MACC1 expression (P=0.0003). Multivariate analysis revealed that MACC1 expression was an independent risk factor of local recurrence (P=0.0016). MACC1 is an independent indicator of recurrence related to RFS in early-stage glottic cancer.

MiR-302 a/b/c suppresses tumor angiogenesis in hepatocellular carcinoma by targeting MACC1.

Hepatocellular carcinoma (HCC) is a hypervascularized tumor. Aberrant angiogenesis is the main cause, which results in cancer growth and progression. It has been showed that microRNA-302 cluster (miR-302) may be associated with angiogenesis. Here, we aimed to identify the role of miR-302a/b/c in the regulation of cell angiogenesis in HCC. MRNA expression of miR-302a/b/c and MACC1 was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The protein of MACC1 was measured using Western blot. Cells proliferation, migration, and invasion abilities were investigated via Cell Counting Kit-8 (CCK-8) assay or transwell assay, respectively. Tube formatting assays were used to explore the tube formation capacity. The interaction among miR-302a/b/c was analyzed by luciferase assay. The expression of miR-302a/b/c was greatly reduced while MACC1 expression, whether mRNA or protein was conspicuously elevated in HCC tissues and cells. Then, functional experiment results showed miR-302a/b/c overexpression and MACC1 down-regulation inhibited the proliferation, migration, invasion ability, and tube formation capacity of HUVECs. In addition, we detected that miR-302a/b/c directly targeted MACC1 and suppressed MACC1 expression, and miR-302a/b/c could suppress tumor angiogenesis in HCC by targeting MACC1. MiR-302a/b/c may function as a potential suppressor of tumor angiogenesis in HCC by targeting MACC1, indicating a promising target for HCC therapy.