Here, we show that this vulnerability is conserved in non-small cell lung cancer (NSCLC), where SMARCA4 loss also results in reduced cyclin D1 expression and selective sensitivity to CDK4/6 inhibitors.
Notably, through Western blot analysis, we found that HJURP suppression remarkably decreased β-catenin, cyclin D1 and c-myc expression level in NSCLC cell lines.
For this purpose, expression levels of TCEAL7 and CCND1 genes were investigated in 50 patients with non-small cell lung cancer by quantitative real time polymerase chain reaction (qRT-PCR).
We found that the co-occurrence of early TP53 mutations in ALK+ NSCLC can lead to chromosomal instability: 24% of TP53-mutated patients showed amplifications of known cancer genes such as MYC (14%), CCND1 (10%), TERT (5%), BIRC2 (5%), ORAOV1 (5%), and YAP1 (5%).
In conclusion, a set of differentially expressed microRNAs in NSCLC was identified and the CCND1 gene was determined as the potential prognostic biomarkers for NSCLC, providing useful information for discovery of future therapeutic targets and candidates in the clinical management of NSCLC.
Additionally, western blot analysis identified that CTD inhibited the phosphatidylinositol 3-kinase (PI3K)/RAC serine/threonine protein kinase (Akt)/mechanistic target of rapamycin (mTOR) signaling pathway in NSCLC, demonstrating that the levels of phosphorylated (p-)Akt, p-mTOR, phosphorylated ribosomal p70S6 protein kinase (p-p70-S6K) and cyclin D1 were significantly decreased following treatment with CTD.
<i>Methods<b>:</b></i> In this study, expression levels of the EMSY and CCND1 genes were investigated in 85 patients with non small cell lung cancer by Real Time PCR.
DISC1 expression was negatively associated with phosphorylated (p-) GSK3β, but positively correlated with a more invasive tumor phenotype and predicted poor NSCLC patient prognosis. siRNA-mediated DISC1 silencing increased p-GSK3β expression and decreased expression of β-catenin and Cyclin D1, while DISC1 upregulation produced the opposite results.
TFPI2AS1 knockdown increased NSCLC cell proliferation and migration, which was associated with enhanced G1/S transition and downregulation of cyclin D1 and cyclin-dependent kinases 2 (CDK2), while TFPI2AS1 overexpression had the opposite effect.
Furthermore, we verified that CCND1 and USP28 were direct targets of miR-3940-5p and also found that the effects of NSCLC cell proliferation and apoptosis by miR-3940-5p were attenuated by overexpression of CCND1 or USP28.
Here, NKX2-1-binding motifs were identified in the <i>cyclin D1</i> promoter, but it has not been clarified whether NKX2-1 is involved in cyclin D1 expression in NSCLC.
Importantly, a positive correlation between the expression of FXR and cyclin D1 was confirmed in NSCLC samples, and patients with high expression of both FXR and cyclin D1 had the worst prognosis.
A correlation between KIF3A loss and a poorer NSCLC prognosis as well as β-catenin and cyclin D1 upregulation further suggests that KIF3A suppresses Wnt/β-catenin signalling and tumourigenesis in NSCLC.
We retrospectively analyzed the expression of β-catenin and cyclin D1 using immunohistochemistry in formalin-fixed paraffin-embedded tissues from 576 patients with early-stage NSCLC.
Furthermore, siRNA-mediated downregulation of CCND1 or CCND2 yielded the same effects on proliferation and cell cycle arrest as miR-146a-5p upregulation did in the NSCLC cell lines.