Purpose
A substantial amount of evidence demonstrates suggests that long non-coding RNAs (lncRNAs) play a key role in the progression of various malignancies, cervical squamous cell carcinoma (CSCC) ...included. In our study, we deeply investigated the role and molecular mechanism of lncRNA NPHS2-6 in CSCC.
Methods
The expression level of gene and protein expression were measured by qRT-PCR and western blot. To test the cell proliferation and cell metastasis ability, we carried out the CCK-8 experiment, clone formation assay, transwell assay and wound healing, respectively. The interactivity among NPHS2-6, miR-1323 and SMC1B were co demonstrated using the bioinformatics tool, dual-luciferase reporter system, and RNA pulldown assay. The subcutaneous tumor model of nude mice was established to verify the results of previous studies at the in vivo. NPHS2-6 was upregulated in CSCC tissues and cells.
Results
NPHS2-6 deficiency significantly inhibited CSCC cell growth and EMT in vitro. In addition, NPHS2-6 deficiency also inhibited the growth of CSCC xenograft tumors in mice in vivo. Importantly, NPHS2-6 was a competing endogenous RNA (ceRNA) to increases SMC1B levels by binding to miR-1323, leading to activate the PI3K/Akt pathway, thereby exacerbating tumorigenesis of CSCC.
Conclusions
In conclusion, NPHS2-6/miR-1323/SMC1B/PI3K/Akt signaling accelerates the progression of CSCC, providing a new direction for the treatment strategy of CSCC.
The eukaryotic structural maintenance of chromosomes (SMC) proteins are involved in key processes of chromosome structure and dynamics. SMC1β was identified as a component of the meiotic cohesin ...complex in vertebrates, which aids in keeping sister chromatids together prior to segregation in meiosis II and is involved in association of homologous chromosomes in meiosis I. The role of SMC1β in meiosis has primarily been studied in mice, where mutant male and female mice are infertile due to germ cell arrest at pachytene and metaphase II stages, respectively. Here, we investigate the function of zebrafish Smc1b to understand the role of this protein more broadly in vertebrates. We found that zebrafish
smc1b
is necessary for fertility and has important roles in meiosis, yet has no other apparent roles in development. Therefore,
smc1b
functions primarily in meiosis in both fish and mammals. In zebrafish, we showed that
smc1b
mutant spermatocytes initiated telomere clustering in leptotene, but failed to complete this process and progress into zygotene. Furthermore, mutant spermatocytes displayed a complete failure of synapsis between homologous chromosomes and homolog pairing only occurred at chromosome ends. Interestingly, meiotic DNA double strand breaks occurred in the absence of Smc1b despite failed pairing and synapsis. Overall, our findings point to an essential role of Smc1b in the leptotene to zygotene transition during zebrafish spermatogenesis. In addition, ovarian follicles failed to form in
smc1b
mutants, suggesting an essential role in female meiosis as well. Our results indicate that there are some key differences in Smc1b requirement in meiosis among vertebrates: while Smc1b is not required for homolog pairing and synapsis in mice, it is essential for these processes in zebrafish.
In this paper, we describe a novel spontaneous mutation of the Smc1b gene coding a cohesin component, which causes female and male sterility. We have discovered an ICR male mouse with a novel ...autosomal recessive gene that causes small gonads and sterility in both sexes. Mutant female and male mice homozygous for the novel sterility gene had normal body weights and showed normal mating behavior, but did not produce any offspring. Histological examination showed that Sertoli cells and spermatogonia were present in the testicular seminiferous tubules in 8-week-old mutant male mice, but no spermatids or spermatozoa were observed. Mutant females showed a markedly reduced number of oocytes with age. The novel sterility gene mapped between D15Mit105 (47.9 cM) and D15Mit171 (54.5 cM) on chromosome 15. Sequences of three candidate sterility genes, Dmc1, Mei1 and Smc1b, which are closely linked to these microsatellite markers, were compared between normal and mutant mice. The Dmc1 and Mei1 genes showed the same sequences in both normal and mutant mice, but the Smc1b gene had a deletion of 16 nucleotides in exon 5, in the mutant mice. We concluded that this deletion led to a frame-shift, which generated a stop codon at position 761 (amino acid 247) of the Smc1b cDNA in mutant mice.
Telomeres have crucial meiosis-specific roles in the orderly reduction of chromosome numbers and in ensuring the integrity of the genome during meiosis. One such role is the attachment of telomeres ...to trans-nuclear envelope protein complexes that connect telomeres to motor proteins in the cytoplasm. These trans-nuclear envelope connections between telomeres and cytoplasmic motor proteins permit the active movement of telomeres and chromosomes during the first meiotic prophase. Movements of chromosomes/telomeres facilitate the meiotic recombination process, and allow high fidelity pairing of homologous chromosomes. Pairing of homologous chromosomes is a prerequisite for their correct segregation during the first meiotic division. Although inner-nuclear envelope proteins, such as SUN1 and potentially SUN2, are known to bind and recruit meiotic telomeres, these proteins are not meiosis-specific, therefore cannot solely account for telomere-nuclear envelope attachment and/or for other meiosis-specific characteristics of telomeres in mammals.
We identify CCDC79, alternatively named TERB1, as a meiosis-specific protein that localizes to telomeres from leptotene to diplotene stages of the first meiotic prophase. CCDC79 and SUN1 associate with telomeres almost concurrently at the onset of prophase, indicating a possible role for CCDC79 in telomere-nuclear envelope interactions and/or telomere movements. Consistent with this scenario, CCDC79 is missing from most telomeres that fail to connect to SUN1 protein in spermatocytes lacking the meiosis-specific cohesin SMC1B. SMC1B-deficient spermatocytes display both reduced efficiency in telomere-nuclear envelope attachment and reduced stability of telomeres specifically during meiotic prophase. Importantly, CCDC79 associates with telomeres in SUN1-deficient spermatocytes, which strongly indicates that localization of CCDC79 to telomeres does not require telomere-nuclear envelope attachment.
CCDC79 is a meiosis-specific telomere associated protein. Based on our findings we propose that CCDC79 plays a role in meiosis-specific telomere functions. In particular, we favour the possibility that CCDC79 is involved in telomere-nuclear envelope attachment and/or the stabilization of meiotic telomeres. These conclusions are consistent with the findings of an independently initiated study that analysed CCDC79/TERB1 functions.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
