Tubulin cofactor A functions as a novel positive regulator of ccRCC progression, invasion and metastasis

Abstract

Microtubules (Mts), which consist of a/b-tubulin heterodimers, are involved in cancer development and metastasis. Tubulin cofactor A (TBCA) plays crucial roles in modulating tubulin folding and a/b-tubulin heterodimer polymerization. Here, we identified the aberrant expression of TBCA in clear cell renal cell carcinoma (ccRCC) specimens as well as cell lines and revealed the function of TBCA as a novel positive regulator in ccRCC progression, invasion and metastasis. qRT-PCR, Western blot and immunohistochemistry assays confirmed that TBCA was significantly highly expressed in ccRCC specimens and cell lines compared to their corresponding normal kidney tissues and HKC. Accordingly, the influence of TBCA on cell proliferation, apoptosis and invasion/migration was detected through overexpression and knockdown of endogenous TBCA protein level in ccRCC cells via plasmids. Silencing of TBCA expression inhibited the proliferation of 786-O cells and Caki-1 cells and promoted the apoptosis of 786-O cells. Down-regulation of TBCA expression also reduced the invasion and migration ability of 786-O cells. Interestingly, overexpression of TBCA did not induce biocharacteristics that directly contrasted to those of TBCA knockdown. Importantly, exploration of the mechanism showed that TBCA could function via modulating cytoskeleton integration and influencing cell cycle progress. Furthermore, down-regulation of TBCA expression in 786-O and Caki-1 cells affected cytoskeleton integration and cell size, induced S/G2 cell cycle arrest and led to cyclineA/E and CDK2 aberrant expression. By investigating novel roles of TBCA in regulation of ccRCC cell progression, invasion and metastasis, our study identified that TBCA may be a potential molecular target for ccRCC therapy.Clear cell renal cell carcinoma (ccRCC) accounts for about 3% of all malignancies. It is the second leading cause of death among all types of urologic tumors. 1 At present, radical or partial nephrectomy is still the most effective treatment for local ccRCC. However, prognosis remains poor for advanced and metastatic ccRCCs because of low sensitivity to chemotherapy and radiotherapy. Recently, molecular targeted therapy has evolved rapidly with the clinical application of tumor-targeted agents such as sorafenib and sunitinib. Unfortunately, the risk of adverse events and disparate treatment outcomes limits the use of these agents. 2,3 Therefore, it is of great importance to find new molecular targets or markers to establish effective strategies for the treatment and early diagnosis of ccRCC.Recently, researchers established that cytoskeletal components including actin, microtubules and intermediate filaments play key roles in cancer development and metastasis. 4,5 Microtubules are a crucial structure for living cells and are involved in many biological functions, such as cell shape, polarity, cell motility, cell division, intracellular transport and cellular architecture. 6 It is composed of a heterodimer, one a-tubulin polypeptide and one b-tubulin polypeptide. A ...

FOXK2 suppresses the malignant phenotype and induces apoptosis through inhibition of EGFR in clear‐cell renal cell carcinoma

“…21,22 All human tissues and xenograft tumor tissues were fixed in 10% neutral formalin and embedded in paraffin. 21,22 All human tissues and xenograft tumor tissues were fixed in 10% neutral formalin and embedded in paraffin.…”

“…IHC assay was performed as previously described. 21,22 All human tissues and xenograft tumor tissues were fixed in 10% neutral formalin and embedded in paraffin. Sections (4 lm thick) were cut serially from paraffin-embedded blocks and mounted on APES-coated glass slides.…”

Concordant developmental expression profiles of orthologues in highly divergent Bilateria

“…We grouped the developmental stages from fertilized 218 egg to the adult body into coarse grained, yet comparable, phases: 'Blas- 219 toderm', 'Gastrulation and Organogenesis', 'Hatching to Larva' and 'Adult' 220 (separated by vertical lines in Fig 5). 221 For all three species, the set L 0 profiles roughly follow the shape of the 222 background profiles across embryogenesis, however at a higher expression 223 level ( Fig 5). In D. melanogaster, expression of bilaterian-specific proteins is 224 initially low, then rises until 'dorsal closure', after which it slighly decreases 225 again.…”

STIM1 phosphorylation triggered by epidermal growth factor mediates cell migration

“…Because the knocking-down of STIM1 has been successfully used to prevent cell migration and metastasis, we consider that the phosphorylation of STIM1 on its modulatory domain is an alternative, easily druggable, target. At the cellular level, migration and invasion are strongly dependent on microtubule dynamics [44], and therefore microtubule polymerization has been considered a significant target in cancer therapy to reduce or prevent metastasis [45]. Many agents such as eribulin, ixabepilone, or cabazitaxel, are currently being used in phase III clinical trials.…”