Transforming Acidic Coiled-coil-containing Protein 3 Research Articles

PI3K/HSCB axis facilitates FOG1 nuclear translocation to promote erythropoiesis and megakaryopoiesis.

Erythropoiesis and megakaryopoiesis are stringently regulated by signaling pathways. However, the precise molecular mechanisms through which signaling pathways regulate key transcription factors controlling erythropoiesis and megakaryopoiesis remain partially understood. Herein, we identified heat shock cognate B (HSCB), which is well known for its iron-sulfur cluster delivery function, as an indispensable protein for friend of GATA 1 (FOG1) nuclear translocation during erythropoiesis of K562 human erythroleukemia cells and cord-blood-derived human CD34+CD90+hematopoietic stem cells (HSCs), as well as during megakaryopoiesis of the CD34+CD90+HSCs. Mechanistically, HSCB could be phosphorylated by phosphoinositol-3-kinase (PI3K) to bind with and mediate the proteasomal degradation of transforming acidic coiled-coil containing protein 3 (TACC3), which otherwise detained FOG1 in the cytoplasm, thereby facilitating FOG1 nuclear translocation. Given that PI3K is activated during both erythropoiesis and megakaryopoiesis, and that FOG1 is a key transcription factor for these processes, our findings elucidate an important, previously unrecognized iron-sulfur cluster delivery independent function of HSCB in erythropoiesis and megakaryopoiesis.

PI3K/HSCB axis facilitates FOG1 nuclear translocation to promote erythropoiesis and megakaryopoiesis

Erythropoiesis and megakaryopoiesis are stringently regulated by signaling pathways. However, the precise molecular mechanisms through which signaling pathways regulate key transcription factors controlling erythropoiesis and megakaryopoiesis remain partially understood. Herein, we identified heat shock cognate B (HSCB), which is well known for its iron–sulfur cluster delivery function, as an indispensable protein for friend of GATA 1 (FOG1) nuclear translocation during erythropoiesis of K562 human erythroleukemia cells and cord-blood-derived human CD34+CD90+hematopoietic stem cells (HSCs), as well as during megakaryopoiesis of the CD34+CD90+HSCs. Mechanistically, HSCB could be phosphorylated by phosphoinositol-3-kinase (PI3K) to bind with and mediate the proteasomal degradation of transforming acidic coiled-coil containing protein 3 (TACC3), which otherwise detained FOG1 in the cytoplasm, thereby facilitating FOG1 nuclear translocation. Given that PI3K is activated during both erythropoiesis and megakaryopoiesis, and that FOG1 is a key transcription factor for these processes, our findings elucidate an important, previously unrecognized iron–sulfur cluster delivery independent function of HSCB in erythropoiesis and megakaryopoiesis.

Abstract 4757: Combining PARP inhibitor with TACC3 inhibition overcomes PARP inhibitor resistance in ovarian cancer

Abstract The treatment of ovarian cancer (OC) presents a significant challenge due to the emergence of resistance to poly (ADP-ribose) polymerase inhibitors (PARPi). Transforming acidic coiled coil containing protein 3 (TACC3) belongs to the TACC family, characterized by its coiled-coil domains. TACC3 plays a crucial role in cell division, particularly in the formation and stability of the mitotic spindle, which is essential for proper chromosome segregation. Mutations or changes in TACC3 have been associated with various cancers, making it an increasingly attractive target for anticancer therapy in recent years. Here, we demonstrated a significant upregulation of TACC3 in OC, correlating with adverse clinical outcomes. Notably, PARPi-resistant OC cells exhibited a marked sensitivity to TACC3 inhibition. This was evidenced by the induction of spindle defects and mitotic catastrophe in PARPi-resistant cells upon TACC3 suppression, achieved either genetically or pharmacologically. Moreover, we explored the therapeutic efficacy of combining TACC3 inhibitor with PARPi, specifically BO-264 with olaparib or niraparib. This combination exhibited a synergistic effect, markedly reducing cell viability in vitro and tumor growth in PARPi-resistant tumor xenograft models. Our study suggests a promising new method for treating ovarian cancer, especially for those resistant to current PARPi treatments, by simultaneously targeting TACC3 and PARPi, enhancing treatment efficacy and potentially improving patient outcomes. Citation Format: Yu Wu, Qilong Wang, Chaolin Deng, Mo Li, Yinan Xiao. Combining PARP inhibitor with TACC3 inhibition overcomes PARP inhibitor resistance in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4757.

Abstract 5269: Evaluation of mitotic spindle inhibitors as cell autonomous inflammatory stimulants in MYC overexpressing breast cancers

Abstract The oncogenic transcription factor MYC is overexpressed in most cancer types, including difficult to treat human malignancies such as receptor triple-negative breast cancers (TNBC). MYC overexpression induces aneuploidy and suppresses anticancer immunity. Elevated levels of MYC can induce mitotic spindle assembly defects and chromosomal instability (CIN) events, exemplified by an increase in cells with micronuclei. These defects are partially mitigated by concomitant upregulation of various mitotic spindle genes. Micronuclei result in cytosolic DNA which can activate cGAS-STING signaling, activating an interferon regulatory transcriptional program responsible for mounting an inflammatory immune response that potentially enhances immune cell recognition. We hypothesized that pharmacological inhibition of specific MYC deregulated mitotic spindle genes will further exacerbate mitotic defects in MYC high cells resulting in synthetic-lethal cell death and additional CIN to activate robust cGAS-STING activation. Interferon activation can increase surface expression of antigen presentation machinery, such as MHC-I, restoring the immunogenicity of MYC high cells. Here, we used mouse breast tumor cells in which MYC expression is conditionally expressed as well as human breast cancer cell lines with different levels of MYC expression. We assessed the anti-proliferative and cytotoxic effects of 9 mitotic small molecular inhibitors that affect spindle function. cGAS-STING activation in inhibitor treated and untreated samples was measured by immunoblotting for pathway proteins phosphorylated TBK1, total TBK1, and IFIT1. Differences in MHC-I cell surface expression was quantified using flow cytometry. Our findings revealed that inhibition of kinesin-like protein KIFC1 and transforming acidic coiled-coil-containing protein 3 (TACC3) induced greater levels of apoptosis in MYC high models. Moreover, inhibition of KIFC1 robustly triggered cGAS-STING activity in MYC high cells as evidenced by increased protein abundance of phospho-TBK1 and IFIT1 in a dose-dependent manner. In addition, sublethal KIFC1 inhibition resulted in increased levels of MHC-I surface expression in MYC high models. Our findings suggest that inhibition of MYC regulated mitotic spindle genes, specifically KIFC1, can serve to preferentially eliminate MYC overexpressing aggressive cancers. Furthermore, sublethal concentrations of a KIFC1 inhibitor can stimulate a tumor cell-intrinsic inflammatory-pathway. Future studies will determine if targeting KIFC1 can enhance the response of MYC high cancers to immunotherapy. Citation Format: Mauricio Jacobo, Andrei Goga. Evaluation of mitotic spindle inhibitors as cell autonomous inflammatory stimulants in MYC overexpressing breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5269.

Abstract LB_B04: Deciphering FGFR3-TACC3 oncogenic fusions

Abstract Chromosomal rearrangements of the fibroblast growth factor receptor (FGFR) genes that give rise to fusions are one of several mechanisms by which the FGF/FGFR signaling axis can become deregulated and result in enhanced signaling in cancer. We have previously identified truncation of exon (E) 18 of FGFR2 as a potent single-driver alteration in cancer, independently of the rearrangement (RE) partner. In contrast, the same does not appear to hold true for its E18-truncated ortholog FGFR3. We mined human oncogenomic datasets from Hartwig Medical Foundation (>2,500 WGS profiles) and Foundation Medicine (>200,000 hybrid-capture panel-seq profiles) for alterations affecting FGFR3. Examination of the structural variants affecting FGFR3 uncovered that 85% of all E18-truncating FGFR3 REs involved transforming acidic coiled-coil-containing protein 3 (TACC3) as the downstream fusion partner gene, while REs with intergenic regions and other known protein-encoding genes were much less frequent. Additionally, there was a clear predominance of self-interacting domains (95%) among all FGFR3 RE partners, with the coiled-coil domain being the most recurrent, suggesting enhanced receptor dimerization and downstream signaling capacity for the majority of the FGFR3 fusions. Our findings led to the generation of a compendium of FGFR3 structural variants which we then functionally tested. In vitro testing of mouse mammary epithelial cells expressing Fgfr3ΔE18-Tacc3E7-E16 fusion variants showed that both E18-truncation and a fusion partner were required for 3D outgrowth and signaling induction. In vivo evaluation of the oncogenic capacity of Fgfr3 variants using somatic delivery of lentiviruses to the mouse mammary gland via intraductal injection and lung via intratracheal injection found that Fgfr3ΔE18-Tacc3E7-E16 fusion variants rapidly induced mammary and lung tumor formation in wild-type and Wap-Cre;Cdh1F/F, and in wild-type and Trp53F/F mice, respectively. In contrast, Fgfr3full-length(FL), Fgfr3ΔE18 and Fgfr3FL–Tacc3E7-E16 were non-tumorigenic. Noteworthy, mammary tumors driven by Fgfr3ΔE18-Tacc3E7-E16 fusions were sensitive to the FGFR inhibitor AZD4547 during a drug intervention study. In summary, our findings show that E18-truncating FGFR3 alterations are recurrent across human cancers and, as opposed to FGFR2 E18-truncating alterations, FGFR3 appears to depend both on E18-truncation and an additional fusion partner with dimerizing capacity. Notably, TACC3 is the most recurrent 3’ fusion partner across all FGFR3 E18-truncating alterations, and somatic tumor modeling has shown that Fgfr3ΔE18-Tacc3 fusions drive mouse mammary and lung tumorigenesis, and are sensitive to FGFR targeted therapy. Citation Format: Julia Yemelyanenko, Jinhyuk Bhin, Sjoerd Klarenbeek, Ji-Ying Song, Catrin Lutz, Marieke van de Ven, Shridar Ganesan, Lodewyk F. A. Wessels, Daniel Zingg, Jos Jonkers. Deciphering FGFR3-TACC3 oncogenic fusions [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_B04.

Knockdown of TACC3 inhibits tumor cell proliferation and increases chemosensitivity in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant digestive tract tumor with limited clinical treatments. Transforming acidic coiled-coil-containing protein 3 (TACC3) is a component of the centrosome axis and a member of the TACC family, which affect mitosis and regulate chromosome stability and are involved in tumor development and progression. However, the role of TACC3 in PDAC remains elusive. In this study, by exploiting the TCGA database, we found that high TACC3 expression in PDAC is associated with poor prognosis. shRNA-mediated TACC3 knockdown caused S phase arrest of the cell cycle and inhibited proliferation in PDAC cell lines. Through RNA sequencing and protein co-immunoprecipitation combined with mass spectrometry, KIF11 was identified as a protein that interacts with TACC3. TACC3 stabilizes and regulates KIF11 protein expression levels in PDAC cells through physical interaction. Knockdown of TACC3 or KIF11 resulted in abnormal spindle formation during cell division both in vitro and in vivo. Pharmacological inhibition of TACC3 or KIF11 can suppress tumor cell proliferation and promote apoptosis. Our studies further demonstrated that high expression of TACC3 and KIF11 mediated the resistance of PDAC to gemcitabine, and deficiency of TACC3 or KIF11 increased the sensitivity of PDAC cells to chemotherapy. In conclusion, our study reveals the fundamental role of TACC3 expression in PDAC cell proliferation and chemoresistance, suggesting that TACC3 can be used as a molecular marker to evaluate the prognosis of PDAC.

TACC3 is an independent prognostic marker, and knockdown of TACC3 enhances the efficacy of CDK1 inhibitor RO3306 in liver cancer cells.

The drug resistance of single-target therapy has gradually become an intractable clinical problem. Combination therapy may be an effective treatment to overcome or postpone drug resistance in cancer. Herein, we discussed the synergistic effect of transforming acidic coiled-coil containing protein 3 (TACC3) suppression and cyclin-dependent kinase 1 (CDK1) in hepatocellular carcinoma (HCC). The Cancer Genome Atlas database and bioinformatics methods were implemented to analyze the expression of CDK1 and TACC3, and predict the biological function of TACC3-related genes in HCC. In addition, in vitro experiments, including cell counting kit 8, transwell and flow cytometry were utilized to evaluate cell proliferation, migration, invasion, cell cycle arrest and apoptosis of HCC cells. Our results demonstrated that TACC3 is an unfavorable and independent prognostic factor to predict poor overall survival (OS) in HCC patients. Genetic inhibition of TACC3 exhibited a remarkable antineoplastic activity of HCC cell lines. Bioinformatic prediction proposed that CDK1 may be the main regulator of TACC3-related genes in HCC. In vitro experimental measurements suggested that a combination of si-TACC3 and CDK1 inhibitor synergistically inhibited cell proliferation and migration, and induced G2 cell cycle arrest and apoptosis of HepG2 or MHCC97H cells. In conclusion, our results revealed a prospective dual-target, TACC3 and CDK1, therapeutic strategy to improve the treatment of HCC.

Transforming acidic coiled-coil containing protein 3 suppresses influenza A virus replication by impeding viral endosomal trafficking and nuclear import

Transforming acidic coiled-coil containing protein 3 (TACC3) is a motor spindle protein that plays an essential role in stabilization of the mitotic spindle. In this study, we show that the overexpression of TACC3 reduces the viral titers of multiple influenza A viruses (IAVs). In contrast, the downregulation of TACC3 increases IAVs propagation. Next, we map the target steps of TACC3 requirement to the early stages of viral replication. By confocal microscopy and nuclear plasma separation experiment, we reveal that overexpression of TACC3 results in a substantial decrease of IAV NP accumulation in the nuclei of infected cells. We further show that viral attachment and internalization are not affected by TACC3 overexpression and detect that the early and late endosomal trafficking of IAV in TACC3 overexpression cells is slower than negative control cells. These results suggest that TACC3 exerts an impaired effect on the endosomal trafficking and nuclear import of vRNP, thereby negatively regulating IAV replication. Moreover, the infection of different IAV subtypes decreases the expression level of TACC3 in turn. Consequently, we speculate that IAV ensures the generation of offspring virions by antagonizing the expression of inhibitory factor TACC3. Collectively, our results establish TACC3 as an important inhibitory factor for replication of the IAV, suggesting that TACC3 could be a potential target for the development of future antiviral compounds.

Targeting TACC3 represents a novel vulnerability in highly aggressive breast cancers with centrosome amplification

Centrosome amplification (CA) is a hallmark of cancer that is strongly associated with highly aggressive disease and worse clinical outcome. Clustering extra centrosomes is a major coping mechanism required for faithful mitosis of cancer cells with CA that would otherwise undergo mitotic catastrophe and cell death. However, its underlying molecular mechanisms have not been fully described. Furthermore, little is known about the processes and players triggering aggressiveness of cells with CA beyond mitosis. Here, we identified Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3) to be overexpressed in tumors with CA, and its high expression is associated with dramatically worse clinical outcome. We demonstrated, for the first time, that TACC3 forms distinct functional interactomes regulating different processes in mitosis and interphase to ensure proliferation and survival of cancer cells with CA. Mitotic TACC3 interacts with the Kinesin Family Member C1 (KIFC1) to cluster extra centrosomes for mitotic progression, and inhibition of this interaction leads to mitotic cell death via multipolar spindle formation. Interphase TACC3 interacts with the nucleosome remodeling and deacetylase (NuRD) complex (HDAC2 and MBD2) in nucleus to inhibit the expression of key tumor suppressors (e.g., p21, p16 and APAF1) driving G1/S progression, and its inhibition blocks these interactions and causes p53-independent G1 arrest and apoptosis. Notably, inducing CA by p53 loss/mutation increases the expression of TACC3 and KIFC1 via FOXM1 and renders cancer cells highly sensitive to TACC3 inhibition. Targeting TACC3 by guide RNAs or small molecule inhibitors strongly inhibits growth of organoids and breast cancer cell line- and patient-derived xenografts with CA by induction of multipolar spindles, mitotic and G1 arrest. Altogether, our results show that TACC3 is a multifunctional driver of highly aggressive breast tumors with CA and that targeting TACC3 is a promising approach to tackle this disease.

Abstract P4-08-20: Inhibition of TACC3 blocks the growth of highly aggressive breast cancers with centrosome amplification

Abstract Centrosome amplification (CA) is a hallmark of cancer that is strongly associated with highly aggressive disease and worse clinical outcome. Enhanced mitotic progression via clustering of extra centrosomes is a major coping mechanism utilized by cancer cells with CA that would otherwise undergo mitotic cell death due to formation of multipolar spindles. However, the underlying molecular mechanisms have largely been unexplored. Furthermore, mitosis-targeting inhibitors have mostly been unsuccessful in clinical settings with poor efficacy and severe side effects. Therefore, there is a dire need to uncover novel molecular mechanisms of CA-driven tumor growth and identify therapeutic targets playing key roles not only in mitosis, but also in interphase of cancer cells with CA to achieve durable anti-tumor effect with minimal toxicity. Here, we identified Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3) as a novel CA-directed dependency, driving highly aggressive cell growth by forming distinct functional interactomes during cell cycle progression. We demonstrated, for the first time, that TACC3 interacts with the Kinesin Family Member C1 (KIFC1) via its TACC domain in mitotic cells with CA to promote centrosome clustering (CC) and facilitate mitotic progression. On the other hand, TACC3 interacts with the members of the nucleosome remodeling and deacetylase (NuRD) complex (HDAC2 and MBD2) in the nucleus of interphase cells with CA, thereby suppressing the transcription of key tumor suppressors to facilitate G1/S progression and cell survival. Inhibiting TACC3 in mitotic cells blocks the formation of TACC3/KIFC1 complex, leading to formation of multipolar spindles and activation of spindle assembly checkpoint (SAC)/CDK1/p-Bcl2 axis that ultimately results in mitotic cell death; whereas TACC3 inhibition in interphase cells blocks TACC3/HDAC2/MBD2 complex, leading to enhanced transcription of cyclin-dependent kinase inhibitors (e.g., p21 and p16) and apoptosis regulators (e.g., APAF1), ultimately causing p53-independent G1 arrest and strong apoptosis. Notably, inducing CA by chemical (cytochalasin D) or genomic (PLK4 overexpression or p53 loss) modulations renders cancer cells highly sensitive to TACC3 inhibition, showing the dependency of cells with CA to TACC3. Targeting TACC3 by small molecule inhibitors or CrispR-CAS9-mediated knock-out significantly reduces colony formation ability, inhibits the growth of organoids of patient-derived xenografts (PDXs) with CA, and strongly inhibits tumor growth in breast cancer cell line xenografts and PDXs with CA. Notably, we demonstrated that high CA tumors express much higher levels of TACC3, and high TACC3 expression, in association with its downstream effectors, KIFC1, HDAC2 and MBD2, leads to drastically worse clinical outcome in cancer patients with CA. Altogether, our results show, for the first time, that TACC3 is a multifunctional driver of the growth of the highly aggressive breast tumors with CA and that targeting TACC3 is a promising approach to tackle this aggressive disease. Citation Format: Ozge Saatci, Ozge Akbulut, Metin Cetin, Vitali Sikirzhytski, Ozgur Sahin. Inhibition of TACC3 blocks the growth of highly aggressive breast cancers with centrosome amplification [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-08-20.

Immunohistochemical Study of The Expression of TACC3 in Colorectal Carcinoma and its Correlation with Other Pathological Prognostic Factors

BACKGROUND: Colorectal cancer (CRC) is the fourth most common cancer comprising nearly 10% of all cancer cases worldwide. Many tumor markers have been used to expect the prognosis of CRC. Transforming acidic coiled- coil-containing protein 3 (TACC3) is one of the TACC family proteins. Physiologically, TACC3 is an important protein in the process of cellular division as it plays a key role in the formation of the mitotic spindle. Pathologically, TACC3 expression was studied in CRC, being found to be a poor prognostic factor. AIM: The aim of the study was to study the expression of TACC3 and its relationship with other clinical and histopathological prognostic factors in patients with CRC. METHODS: This is an observational and immunohistochemical study on 45 resection specimens from 45 CRC cases. This study was conducted at the pathology departments of the Faculty of Medicine, Cairo University, and Faculty of Medicine, Fayoum University from July 2019 to February 2020 Tumor tissues were prepared as formalin- fixed and paraffin-embedded specimens. The paraffin blocks were sectioned at the 5 microns thickness. Then, the collected sections were stained with hematoxylin & eosin for histopathological revision and immune-histochemical staining for TACC3 proteins. RESULTS: The mean immunoreactivity score (IRS) for the TACC3 expression in our sample was 70 ± 89.91. TACC3 IRS score was significantly higher in those tumors with N2 stage (IRS = 175 ± 107.1; p = 0.02), and with Stage III tumors (IRS = 136.4 ± 93.5; p = 0.04). The other parameters showed no statistically significant relationship with IRS scores. CONCLUSION: Immunohistochemical expression of TACC3 would be valuable as a prognostic marker in cases of colorectal adenocarcinoma, where the expression was found to show stronger and more widespread expression in cases with higher stages. Furthermore, TACC3 should therefore be considered as a potential candidate for targeted therapy, where its blockade may hinder the tumor’s ability to proliferate and progress.

Bladder cancer course, four genetic high-risk variants, and histopathological findings.

Urinary bladder cancer, a smoking and occupation related disease, was subject of several genome-wide association studies (GWAS). However, studies on the course of the disease based on GWAS findings differentiating between muscle invasive bladder cancer (MIBC) and non-muscle invasive bladder cancer (NMIBC) are rare. Thus we investigated 4 single nucleotide polymorphisms (SNPs) detected in GWAS, related to the genes coding for TACC3 (transforming, acidic coiled-coil containing protein 3), for FGFR3 (fibroblast growth factor receptor 3), for PSCA (prostate stem cell antigen) and the genes coding for CBX6 (chromobox homolog 6) and APOBEC3A (apolipoprotein B mRNA editing enzyme, catalytic polypeptide-like 3A). This study is based on 712 bladder cancer patients and 875 controls from 3 different case control studies in Germany. The 4 SNPs of interest (PSCA rs2294008 and rs2978974, FGFR3-TACC3 rs798766, and CBX6-APOBEC3A rs1014971) were determined by real-time polymerase chain reaction. The distribution of the 4 SNPs does not vary significantly between cases and controls in the entire study group and in the 3 local subgroups, including two former highly industrialized areas and a region without such history. Also, no significant differences in the bladder cancer subgroups of MIBC and NMIBC were observed. The 4 investigated SNPs do not noticeably contribute differently to the bladder cancer risk for the bladder cancer subgroups of MIBC and NMIBC.

Tumor-augmenting Effect of Histone Methyltransferase WHSC1 on Colorectal Cancer Via Epigenetic Upregulation of TACC3 and PI3K/Akt Activation

Wolf-Hirschhorn syndrome candidate 1 (WHSC1) is a histone methyltransferase which is frequently expressed in an aberrant manner in tumors, but its specific roles and targets in colorectal cancer (CRC) remain unclear. Expression of WHSC1 in CRC tissues and cells was examined by RT-qPCR, immunohistochemistry and immunoblot assays. WHSC1 was knocked down in CRC cells to examine its effect on cell proliferation, invasiveness, migration, epithelial-mesenchymal transition (EMT) activity and apoptosis. The binding between WHSC1 and transforming acidic coiled-coil containing protein 3 (TACC3) was predicted using bioinformatics systems and subsequently validated. In addition, altered expression of TACC3 was introduced into CRC cells to perform functional assays. Stably transfected cells were injected into nude mice to induce xenograft tumors. WHSC1 was highly expressed in CRC tumor tissues and cells with a positive correlation with TACC3 concentration. Specific downregulation of WHSC1 in two CRC cell lines blocked cell proliferation, invasiveness, EMT and migration activity and promoted cell apoptosis. WHSC1 triggers H3K36me2 modification at the level of the TACC3 promoter to induce TACC3 activation. TACC3 suppression similarly blocked the malignant activity of CRC cells, whereas TACC3 restoration in cells counteracted the cancer-suppressive functions of WHSC1 silencing. TACC3 levels were correlated with increased phosphorylation of the PI3K/Akt signaling pathway in cells. Likewise, WHSC1 suppression blocked tumor growth in nude mice. The results of this study revealed TACC3 as a target of WHSC1 in CRC that is positively correlated with PI3K/Akt pathway activation and tumor development.

Discovery of novel analogs of KHS101 as transforming acidic coiled coil containing protein 3 (TACC3) inhibitors for the treatment of glioblastoma

Transforming acidic coiled coil containing protein 3 (TACC3) is emerging as an attractive anticancer target in recent years, however, few TACC3 small-molecular inhibitors have been reported up to now. In this study, fifteen compounds were designed and synthesized based on the lead compound KHS101 to find more potent TACC3 inhibitors. Among them, the most potent compound 7g exhibited about 10-folds more potent antiproliferative activities than KHS101 in various cancer cell lines. Two different protein-drug binding assays including DARTS, and CETSA revealed TACC3 as a biologically relevant target of compound 7g. In addition, compound 7g induced cell cycle arrest at the G2/M phase and induced cell apoptosis. Furthermore, compound 7g depolarized the MMP and induced ROS generation in a dose-dependent manner in U87 cells. More importantly, 7g reduced tumor weight by 72.7% in U87 xenograft model at a dose of 20 mg/kg/day without obvious toxicity. Altogether, compound 7g deserved further investigations as a novel, safe and efficacious TACC3 inhibitor for the treatment of GBM.

E2F1 promotes cell cycle progression by stabilizing spindle fiber in colorectal cancer cells

BackgroundE2F1 is a transcription factor that regulates cell cycle progression. It is highly expressed in most cancer cells and activates transcription of cell cycle-related kinases. Stathmin1 and transforming acidic coiled-coil-containing protein 3 (TACC3) are factors that enhance the stability of spindle fiber.MethodsThe E2F1-mediated transcription of transforming acidic coiled-coil-containing protein 3 (TACC3) and stathmin1 was examined using the Cancer Genome Atlas (TCGA) analysis, quantitative polymerase chain reaction (qPCR), immunoblotting, chromatin immunoprecipitation (ChIP), and luciferase reporter. Protein–protein interaction was studied using co-IP. The spindle structure was shown by immunofluorescence. Phenotype experiments were performed through MTS assay, flow cytometry, and tumor xenografts. Clinical colorectal cancer (CRC) specimens were analyzed based on immunohistochemistry.ResultsThe present study showed that E2F1 expression correlates positively with the expression levels of stathmin1 and TACC3 in colorectal cancer (CRC) tissues, and that E2F1 transactivates stathmin1 and TACC3 in CRC cells. Furthermore, protein kinase A (PKA)-mediated phosphorylation of stathmin1 at Ser16 is essential to the phosphorylation of TACC3 at Ser558, facilitating the assembly of TACC3/clathrin/α-tubulin complexes during spindle formation. Overexpression of Ser16-mutated stathmin1, as well as knockdown of stathmin1 or TACC3, lead to ectopic spindle poles including disorganized and multipolar spindles. Overexpression of wild-type but not Ser16-mutated stathmin1 promotes cell proliferation in vitro and tumor growth in vivo. Consistently, a high level of E2F1, stathmin1, or TACC3 not only associates with tumor size, lymph node metastasis, TNM stage, and distant metastasis, but predicts poor survival in CRC patients.ConclusionsE2F1 drives the cell cycle of CRC by promoting spindle assembly, in which E2F1-induced stathmin1 and TACC3 enhance the stability of spindle fiber.

Elevated expression of transforming acidic coiled-coil-containing protein 3 (TACC3) reflects aggressiveness of primary central nervous system lymphomas.

Transforming acidic coiled-coil-containing protein 3 (TACC3) plays an important role in centrosome/microtubule dynamics. Deregulation of centrosomes/microtubules causes mitotic spindle defects, leading to tumorigenesis. However, the correlation between TACC3 and primary central nervous system lymphomas (PCNSLs) is unknown. The present study investigated the association between the immunohistochemical expression of TACC3, p53, and Ki-67, and the clinical factors in 40 PCNSLs. We evaluated the staining of TACC3 based on the histoscore (H-score) that contains a semiquantitative evaluation of both the intensity of staining, and the percentage of positive cells. Expression level of each component was classified as low or high according to the median H-score value. Patients with PCNSLs were divided into groups depending on TACC3 expression levels (no expression and low expression, 18; high expression, 22). Disease-free survival and overall survival of patients with high TACC3 expression were significantly shorter (p < 0.01 and p < 0.05, respectively). These results suggest that elevated expression of TACC3 could reflects aggressiveness of primary central nervous system lymphomas.

High Expression of TACC3 Is Associated with the Poor Prognosis and Immune Infiltration in Lung Adenocarcinoma Patients.

Background Lung adenocarcinoma (LUAD) has been recognized as one of the commonest aggressive malignant tumors occurring in humans. The transforming acidic coiled-coil-containing protein 3 (TACC3) seems to be a probable prognostic marker and treatment target for non-small-cell lung cancer (NSCLC). Nevertheless, there exist no reports on the association between TACC3 and immunotherapy or other therapeutic interventions in LUAD. Methods Premised on the data accessed from The Cancer Genome Atlas- (TCGA-) LUAD, we carried out bioinformatics analysis. The TACC3 expression in LUAD was analyzed utilizing the GEPIA. A survival module was constructed to evaluate the effect of TACC3 on the survival of patients with LUAD. Logistic regression was undertaken to examine the relationship between TACC3 expression and clinical factors. Protein-protein interaction analysis was performed in the GeneMANIA database, and enrichment analysis and identification of predicted signaling pathways were performed using Gene Ontology and Kyoto Encyclopedia of Genes. Additionally, the Cox regression was used to assess the clinicopathologic features linked to the overall survival in TCGA patients. Lastly, we investigated the link between TACC3 and tumor-infiltrating immune cells (TIICs) through CIBERSORT and the “Correlation” module of GEPIA. The association between TACC3 gene expression and drug response was analyzed using the CellMiner database to predict drug sensitivity. Results The outcomes illustrated that TACC3 was upregulated and considerably correlated with dismal prognosis in LUAD patients. Moreover, the multivariate Cox regression analysis depicted TACC3 as an independent prognostic marker in LUAD patients. It was also revealed that the expression of TACC3 was related to clinical stage (P = 0.014), age (P = 0.002), and T classification (P ≤ 0.018). Moreover, we discovered that the expression of TACC3 was considerably linked to a wide range of TIICs, especially the T cells and NK cells. Single-cell results found that TACC3 was mainly expressed in the immune cells (especially tprolif cells) and malignant cells. TACC3 gene expression was positively correlated with TMB and MSI, and TACC3 may provide a prediction of the efficacy of immunotherapy. Moreover, the correlation analysis between TACC3 gene expression and immune checkpoint gene expression revealed that TACC3 may coordinate the activities of these ICP genes in different signal transduction pathways. TACC3 is related to biological progress (BP), cellular component (CC), and molecular function (MF). The pathways involved in the interaction network involving TACC3 include nonhomologous end-joining, RNA transport, pantothenate and CoA biosynthesis, homologous recombination, and nucleotide excision repair. Furthermore, we investigated the association between the expression of TACC3 and the use of antitumor drugs, and TACC3 was positively correlated with response to most drugs. Conclusion The findings from this research offer robust proof that the expression of TACC3 could be a prognostic marker correlated with TIICs in LUAD. TACC3 can also provide new ideas for immunotherapy as a potential therapeutic target.

TACC3 expression as a prognostic factor in aggressive types of adult T-cell leukemia/lymphoma patients.

Adult T-cell leukemia/lymphoma (ATLL) is a malignant peripheral T-cell neoplasm associated with human T-cell leukemia virus type-1 (HTLV-1). The acute and lymphoma subtypes are regarded as aggressive ATLLs, and the overall survival (OS) of patients remains poor. Transforming acidic coiled-coil-containing protein 3 (TACC3) regulates microtubules, which are associated with cancer-related proteins overexpressed in various cancers. Such a relationship has not been reported in hematopoietic tumors, including ATLL. We examined tissue microarrays of histological samples from 92 cases of aggressive ATLL and assessed clinical features, including TACC3 protein expression levels. Compared with TACC3-low, TACC3-high ATLL patients were significantly older (P<.001), with a tendency toward pleomorphic variant over other morphological classifications (P=.019). TACC3-high patients (median survival time [MST] 10.6months, confidence interval [CI] [6.27-15.6]) had poorer OS compared to TACC3-low patients (MST 20months, CI [9.43-38.5]) (P=.0168). Moreover, multivariate analysis on TACC3 expression levels suggests that TACC3-high is an independent significant prognostic factor (HR, 1.700; 95% CI, 1.037-2.753; P=.0355). Certain drugs that inhibit TACC3-overexpressing neoplastic cells are used clinically. Further studies might highlight a key role for TACC3 in the oncogenesis and progression of ATLL.

Functions of FGFR2 corrupted by translocations in intrahepatic cholangiocarcinoma

Cholangiocarcinoma, originating from the biliary duct, represents a subset of liver cancer. With about 8000 new cases of cholangiocarcinoma diagnosed annually in the U.S., these fall into three categories: intrahepatic, peri-hilar, and extrahepatic cholangiocarcinoma. Arising from the epithelium of the bile duct, intrahepatic cholangiocarcinoma (ICC) is a universally fatal malignancy with very few treatment options. The poor prognosis and lack of molecular targeted therapies highlights ICC as a critical unmet medical need. With advances in sequencing technology, numerous chromosomal translocations have been discovered as drivers in cancer initiation and progression. Particularly in ICC, chromosomal translocations involving Fibroblast Growth Factor Receptor 2 (FGFR2) have been frequently identified, resulting in the creation of oncogenic fusion proteins. At the N-terminus, these fusion proteins share a nearly-identical FGFR2 moiety retaining an intact kinase domain and, at the C-terminus, a dimerization/oligomerization domain provided by different partner genes, including: Periphilin 1 (PPHLN1), Bicaudal family RNA binding protein 1 (BICC1), Adenosylhomocysteinase Like 1 (AHCYL1), and Transforming Acidic Coiled-Coil Containing Protein 3 (TACC3). A number of pre-clinical and clinical trials have shown the effectiveness of FGFR inhibitors in treating FGFR2 fusion-positive ICC patients. However, the efficacy of these inhibitors may be short-lived due to acquired resistance. In this review, we provide an overview of FGFR2 fusions, comparing their structures and mechanism of dimerization, examining the importance of FGFR2 as a partner gene, as well as highlighting the significance of alternative splicing of FGFR2 in these fusion proteins. In addition, we discuss various therapeutic options and their associated potencies in targeting these translocation-induced ICCs.

The microtubule-associated protein HURP recruits the centrosomal protein TACC3 to regulate K-fiber formation and support chromosome congression

Kinetochore fibers (K-fibers) are microtubule bundles attached to chromosomes. Efficient K-fiber formation is required for chromosome congression, crucial for faithful chromosome segregation in cells. However, the mechanisms underlying K-fiber formation before chromosome biorientation remain unclear. Depletion of hepatoma up-regulated protein (HURP), a RanGTP-dependent microtubule-associated protein localized on K-fibers, has been shown to result in low-efficiency K-fiber formation. Therefore, here we sought to identify critical interaction partners of HURP that may modulate this function. Using co-immunoprecipitation and bimolecular fluorescence complementation assays, we determined that HURP interacts directly with the centrosomal protein transforming acidic coiled coil-containing protein 3 (TACC3), a centrosomal protein, both in vivo and in vitro through the HURP1-625 region. We found that HURP is important for TACC3 function during kinetochore microtubule assembly at the chromosome region in prometaphase. Moreover, HURP regulates stable lateral kinetochore attachment and chromosome congression in early mitosis by modulation of TACC3. These findings provide new insight into the coordinated regulation of K-fiber formation and chromosome congression in prometaphase by microtubule-associated proteins.