The prognostic potential of coilin in association with p27 expression in pediatric acute lymphoblastic leukemia for disease relapse

UHMK1-dependent phosphorylation of Cajal body protein coilin alters 5-FU sensitivity in colon cancer cells

Resistance to 5-fluorouracil (5-FU) in chemotherapy and recurrence of colorectal tumors is a serious concern that impedes improvements to clinical outcomes. In the present study, we found that conditioned medium (CM) derived from 5-FU-resistant HCT-8/FU cells reduced 5-FU chemosensitivity in HCT-8 colon cancer cells, with corresponding changes to number and morphology of Cajal bodies (CBs) as observable nuclear structures. We found that U2AF homology motif kinase 1 (UHMK1) altered CB disassembly and reassembly and regulated the phosphorylation of coilin, a major component of CBs. This subsequently resulted in a large number of variations in RNA alternative splicing that affected cell survival following 5-FU treatment, induced changes in intracellular phenotype, and transmitted preadaptive signals to adjacent cells in the tumor microenvironment (TME). Our findings suggest that CBs may be useful for indicating drug sensitivity or resistance in tumor cells in response to stress signals. The results also suggest that UHMK1 may be an important factor for maintaining CB structure and morphology by regulating splicing events, especially following cellular exposure to cytotoxic drugs.

Suppression of TCAB1 expression induced cellular senescence by lessening proteasomal degradation of p21 in cancer cells

Background

TCAB1, a.k.a. WRAP53β or WDR79, is an important molecule for the maintenance of Cajal bodies and critically involved in telomere elongation and DNA repair. Upregulation of TCAB1 were discovered in a variety types of cancers. However, the function of TCAB1 in tumor cell senescence remains absent.

Methods

The TCAB1 knockdown cell lines were constructed. The expression levels of TCAB1, p21, p16 and p53 were detected by qRT-PCR and western blotting. Staining of senescence-associated β-galactosidase was used to detect senescent cells. The ubiquitination of the p21 was analysed by immunoprecipitation and in vivo ubiquitination assay. TCGA databases were employed to perform in silico analyses for the mRNA expression of TCAB1, p21, p16 and p53.

Results

Here, we discovered that knockdown of TCAB1 induced rapid progression of cellular senescence in A549, H1299 and HeLa cells. In exploiting the mechanism underlining the role of TCAB1 on senescence, we found a significant increase of p21 at the protein levels upon TCAB1 depletion, whereas the p21 mRNA expression was not altered. We verified that TCAB1 knockdown was able to shunt p21 from proteasomal degradation by regulating the ubiquitination of p21. In rescue assays, it was demonstrated that decreasing the expression of p21 or increasing the expression of TCAB1 were able to attenuate the cellular senescence process induced by TCAB1 silencing.

Conclusions

This study revealed the importance of TCAB1 for its biological functions in the regulation of cell senescence. Our results will be helpful to understand the mechanisms of senescence in cancer cells, which could provide clues for designing novel strategies for developing effective treatment regimens.

Propofol inhibits proliferation and cisplatin resistance in ovarian cancer cells through regulating the microRNA‑374a/forkhead box O1 signaling axis

Ovarian cancer is a prominent disease that demonstrates high incidence rates in women and often presents multidrug resistance. Propofol has been demonstrated to suppress the malignancy of various types of human cancer; however, the underlying molecular mechanisms of propofol in ovarian cancer remain largely unknown. The present study aimed to investigate whether and how propofol inhibits proliferation and cisplatin (DDP) resistance in ovarian cancer cells. Ovarian cancer cell viability was assessed by the Cell Counting kit-8 assay; apoptosis and cell cycle progression were determined by flow cytometry; the relative expression levels of microRNA (miR)-374a and forkhead box O1 (FOXO1) were analyzed using reverse transcription-quantitative PCR; the binding ability of miR-374a to FOXO1 was assessed by the dual-luciferase reporter assay; cellular sensitivity to DDP was detected using the MTT assay; and finally, the protein expression levels of FOXO1, p27, and Bcl-2-like-protein 11 (Bim) were analyzed by western blotting. Propofol reduced viability, promoted apoptosis and decreased miR-374a expression levels in A2780 cells. In addition, the viability of A2780/DDP cells in the propofol + DDP treatment group was significantly inhibited, and the apoptotic rate was increased. In addition, miR-374a overexpression increased cell viability and the proportion of cells in the S phase, and decreased the proportion of cells in the G0/G1 phase. Conversely, genetic knockdown of miR-374a exerted the opposite effects on cell viability and cell cycle progression. Moreover, miR-374a was demonstrated to bind to FOXO1. Propofol promoted the expression of FOXO1, p27 and Bim, induced cell cycle arrest and decreased ovarian cancer cell viability. In addition, treatment with propofol and DDP regulated FOXO1 and increased apoptosis of ovarian cancer cells. In conclusion, propofol downregulated miR-374a and modulated the FOXO1 pathway to reduce proliferation and DDP resistance in ovarian cancer cells.

An improved advanced fragment analysis-based classification and risk stratification of pediatric acute lymphoblastic leukemia

Background

Acute lymphoblastic leukemia (ALL) contains cytogenetically distinct subtypes that respond differently to cytotoxic drugs. Therefore, subtype classification is important and indispensable in ALL diagnosis. In our previous study, we identified some marker genes in childhood ALL by means of microarray technology and, furthermore, detected the relative expression levels of 57 marker genes and built a comparatively convenient and cost-effective classifier with a prediction accuracy as high as 94% based on the advanced fragment analysis (AFA) technique.

Methods

A more convenient improved AFA (iAFA) technique with one-step multiplex RT-PCR and an anti-contamination system was developed to detect 57 marker genes for ALL.

Results

The iAFA assay is much easier and more convenient to perform than the previous AFA assay and has a prediction accuracy of 95.29% in ALL subtypes. The anti-contamination system could effectively prevent the occurrence of lab DNA contamination. We also showed that marker gene expression profiles in pediatric ALL revealed 2 subgroups with different outcomes. Most ALL patients (95.8%) had a good-risk genetic profile, and only 4.2% of ALL patients had a poor-risk genetic profile, which predicted an event-free survival (EFS) of 93.6 ± 1.3% vs 18.8 ± 9.8% at 5 years, respectively (P < 0.001).

Conclusions

Compared to the previous AFA assay, the iAFA technique is more functional, time-saving and labor-saving. It could be a valuable clinical tool for the classification and risk stratification of pediatric ALL patients.

Long noncoding RNA GAS5 impairs the proliferation and invasion of endometrial carcinoma induced by high glucose via targeting miR-222-3p/p27

Long noncoding RNAs (lncRNAs) have been identified to be critical functional regulator in the human tumors, while the deepgoing mechanism by which lncRNAs modulates the endometrial carcinoma is still elusive. In this work, we found that lncRNA GAS5 was under-expressed in the endometrial carcinoma tissue specimens, especially these samples with type 2 diabetes mellitus. Besides, the aberrant under-expression of GAS5 was correlated with the advanced tumor stage as well as poor prognosis outcome. In cellular experiments, GAS5 was decreased in the cells exposed to the high glucose. Enforced GAS5 expression repressed the tumor phenotype of endometrial carcinoma cells, including proliferation and invasion. Molecular mechanism study further demonstrated that GAS5 functioned as a sponge for miR-222-3p, abrogating its ability of inhibiting p27 protein expression. In conclusion, these results confirmed the vital regulation of GAS5/miR-222-3p/p27 axis in the endometrial carcinoma tumorigenesis.

Understanding the evolutionary trend of intrinsically structural disorders in cancer relevant proteins as probed by Shannon entropy scoring and structure network analysis

BACKGROUND

Malignant diseases have become a threat for health care system. A panoply of biological processes is involved as the cause of these diseases. In order to unveil the mechanistic details of these diseased states, we analyzed protein families relevant to these diseases.

RESULTS

Our present study pivots around four apparently unrelated cancer types among which two are commonly occurring viz. Prostate Cancer, Breast Cancer and two relatively less frequent viz. Acute Lymphoblastic Leukemia and Lymphoma. Eight protein families were found to have implications for these cancer types. Our results strikingly reveal that some of the proteins with implications in the cancerous cellular states were showing the structural organization disparate from the signature of the family it constitutes. The sequences were further mapped onto respective structures and compared with the entropic profile. The structures reveal that entropic scores were able to reveal the inherent structural bias of these proteins with quantitative precision, otherwise unseen from other analysis. Subsequently, the betweenness centrality scoring of each residue from the structure network models was resorted to explore the changes in dependencies on residue owing to structural disorder.

CONCLUSION

These observations help to obtain the mechanistic changes resulting from the structural orchestration of protein structures. Finally, the hydropathy indexes were obtained to validate the sequence space observations using Shannon entropy and in-turn establishing the compatibility.