Background
Adrenocortical carcinoma (ACC) is a rare and aggressive malignant cancer in the adrenal cortex with poor prognosis. Though previous research has attempted to elucidate the progression of ACC, its molecular mechanism remains poorly understood.
Methods
Gene transcripts per million (TPM) data were downloaded from the UCSC Xena database, which included ACC (The Cancer Genome Atlas, n = 77) and normal samples (Genotype Tissue Expression, n = 128). We used weighted gene co-expression network analysis to identify gene connections. Overall survival (OS) was determined using the univariate Cox model. A protein–protein interaction (PPI) network was constructed by the search tool for the retrieval of interacting genes.
Results
To determine the critical genes involved in ACC progression, we obtained 2,953 significantly differentially expressed genes and nine modules. Among them, the blue module demonstrated significant correlation with the “Stage” of ACC. Enrichment analysis revealed that genes in the blue module were mainly enriched in cell division, cell cycle, and DNA replication. Combined with the PPI and co-expression networks, we identified four hub genes (i.e., TOP2A, TTK, CHEK1, and CENPA) that were highly expressed in ACC and negatively correlated with OS. Thus, these identified genes may play important roles in the progression of ACC and serve as potential biomarkers for future diagnosis.
By analyzing 4987 cancer transcriptomes from The Cancer Genome Atlas (TCGA), we identified that excision repair cross-complementation group 6 like (ERCC6L), a newly discovered DNA helicase, is highly expressed in 12 solid cancers. However, its role and mechanism in tumorigenesis are largely unknown. In this study, we found that ERCC6L silencing by small interring RNA (siRNA) or short hairpin RNA (shRNA) significantly inhibited the proliferation of breast (MCF-7, MDA-MB-231) and kidney cancer cells (786-0). Furthermore, ERCC6L silencing induced cell cycle arrest at G0/G1 phase without affecting apoptosis. We then performed RNA sequencing (RNA-seq) analysis after ERCC6L silencing and identified that RAB31 was markedly downregulated at both the transcriptional and translational levels. Its downstream protein, phosphorylated MAPK and CDK2 were also inhibited by ERCC6L silencing. The xenograft experiment showed that silencing of ERCC6L strikingly inhibited tumor growth from the 7th day after xenograft in nude mice. In addition, higher ERCC6L expression was found to be significantly associated with worse clinical survival in breast and kidney cancers. In conclusion, our results suggest that ERCC6L may stimulates cancer cell proliferation by promoting cell cycle through a way of RAB31-MAPK-CDK2, and it could be a potential biomarker for cancer prognosis and target for cancer treatment.
Centenarians (CENs) are excellent subjects to study the mechanisms of human longevity and healthy aging. Here, we analyzed the transcriptomes of 76 centenarians, 54 centenarian-children, and 41 spouses of centenarian-children by RNA sequencing and found that, among the significantly differentially expressed genes (SDEGs) exhibited by CENs, the autophagy-lysosomal pathway is significantly up-regulated. Overexpression of several genes from this pathway, CTSB, ATP6V0C, ATG4D, and WIPI1, could promote autophagy and delay senescence in cultured IMR-90 cells, while overexpression of the Drosophila homolog of WIPI1, Atg18a, extended the life span in transgenic flies. Interestingly, the enhanced autophagylysosomal activity could be partially passed on to their offspring, as manifested by their higher levels of both autophagyencoding genes and serum beclin 1 (BECN1). In light of the normal age-related decline of autophagy-lysosomal functions, these findings provide a compelling explanation for achieving longevity in, at least, female CENs, given the gender bias in our collected samples, and suggest that the enhanced waste-cleaning activity via autophagy may serve as a conserved mechanism to prolong the life span from Drosophila to humans.
Heterogeneity in transcriptional data hampers the identification of differentially expressed genes (DEGs) and understanding of cancer, essentially because current methods rely on cross-sample normalization and/or distribution assumption—both sensitive to heterogeneous values. Here, we developed a new method, Cross-Value Association Analysis (CVAA), which overcomes the limitation and is more robust to heterogeneous data than the other methods. Applying CVAA to a more complex pan-cancer dataset containing 5,540 transcriptomes discovered numerous new DEGs and many previously rarely explored pathways/processes; some of them were validated, both in vitro and in vivo, to be crucial in tumorigenesis, e.g., alcohol metabolism (ADH1B), chromosome remodeling (NCAPH) and complement system (Adipsin). Together, we present a sharper tool to navigate large-scale expression data and gain new mechanistic insights into tumorigenesis.
DNA replication is precisely regulated in cells and its dysregulation can trigger tumorigenesis. Here we identified that the TOPBP1 interacting checkpoint and replication regulator (
TICRR
) mRNA level was universally and highly expressed in 15 solid cancer types. Depletion of
TICRR
significantly inhibited tumor cell growth, colony formation and migration
in vitro
, and strikingly inhibited tumor growth in the xenograft model. We reveal that knockdown of
TICRR
inhibited not only the initiation but also the fork progression of DNA replication. Suppression of DNA synthesis by
TICRR
silencing caused DNA damage accumulation, subsequently activated the ATM/CHK2 dependent p53 signaling, and finally induced cell cycle arrest and apoptosis at least in p53-wild cancer cells. Further, we show that a higher
TICRR
level was associated with poorer overall survival (OS) and disease free survival (DFS) in multiple cancer types. In conclusion, our study shows that
TICRR
is involved in tumorigenesis by regulating DNA replication, acting as a common biomarker for cancer prognosis and could be a promising target for drug-development and cancer treatment.
Centenarians are a good healthy aging model. Interestingly, centenarians’ offspring are prone to achieve longevity. Here we recruited 60 longevity families and investigated the blood biochemical indexes of family members to seek candidate factors associated with familial longevity. First, associations of blood indexes with age were tested. Second, associations of blood parameters in centenarians (CEN) with their first generation of offspring (F1) and F1 spouses (F1SP) were analyzed. Third, genes involved in regulating target factors were investigated. We found that total cholesterol (TC) and triglyceride (TG) increased with age (20–80 years), but decreased in CEN. Similarly, blood urea nitrogen (BUN) and blood creatinine (BCr) increased with age (20–80 years), but were maintained on a plateau in CEN. Importantly, we first revealed dual changes in blood pressure, i.e., decreased diastolic blood pressure but increased systolic blood pressure in CEN, which associated with altered CST3 expression. Genetic analysis revealed a significant association of blood uric acid (BUA) and BCr in CEN with F1 but not with F1SP, suggesting they may be heritable traits. Taken together, our results suggest serum lipids, kidney function and especially diastolic pressure rather than systolic pressure were improved in CEN or their offspring, suggesting these factors may play an important role in familial longevity.
Responses of plant traits to climate changes are complex, which could be mirrored by the investigations of herbarium specimens. By examining specimens of Rosa and Cotoneaster species collected since 1920s in Hengduan Mountains, we analyzed the changes of flowering phenology and flower size in the past century when climate changes were considered to be intensified. We found that flowering phenology of Rosa showed no significant change, but flowering phenology of Cotoneaster was delayed in recent years. Flower size of Rosa species showed a marginally significant decrease over the past century. The results suggested that responses of flowering time to global changes and pollinator mediated selection on floral traits might be more complex than what were expected. Our results indicated that future researches based on investigations of herbarium specimens should be carried out on multiple plant species with different flower structures and life histories to better understand the effects of climate changes on plant traits.
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