DIMT1 overexpression correlates with progression and prognosis in gastric carcinoma

Fault-Tolerance Study on a Positive-Charged Cleft in 18S rRNA Methyltransferase DIMT1

Dimethyladenosine transferase 1 (DIMT1) is an RNA N6,6-dimethyladenosine (m26,6A) methyltransferase. DIMT1's role in pre-rRNA processing and ribosome biogenesis is critical for cell proliferation. Here, we investigated the minimal number of residues in a positively charged cleft on DIMT1 required for cell proliferation. We demonstrate that a minimum of four residues in the positively charged cleft must be mutated to alter DIMT1's RNA-binding ability. The variant (4mutA-DIMT1), which presents reduced RNA binding affinity, is diffuse in the nucleoplasm and nucleolus, in contrast with the primarily nucleolar localization of wild-type DIMT1. The aberrant cellular localization significantly impaired 4mutA-DIMT1's role in supporting cell proliferation, as shown in competition-based cell proliferation assays. These results identify the minimum region in DIMT1 to target for cell proliferation regulation.

Nucleophosmin 1 is a prognostic marker of gastrointestinal cancer and is associated with m6A and cuproptosis

Background: NPM1 is highly expressed in a variety of solid tumors and promotes tumor development. However, there are few comprehensive studies on NPM1 analysis in gastrointestinal cancer.

Methods: We used bioinformatics tools to study the expression difference of NPM1 between gastrointestinal cancer and control group, and analyzed the relationship between its expression level and the diagnosis, prognosis, functional signaling pathway, immune infiltration, m6A and cuproptosis related genes of gastrointestinal cancer. At the same time, the expression difference of NPM1 between esophageal carcinoma (ESCA) samples and control samples was verified by in vitro experiments.

Results: NPM1 was overexpressed in gastrointestinal cancer. In vitro experiments confirmed that the expression of NPM1 in ESCA samples was higher than that in normal samples. The expression of NPM1 has high accuracy in predicting the outcome of gastrointestinal cancer. The expression of NPM1 is closely related to the prognosis of multiple gastrointestinal cancers. Go and KEGG enrichment analysis showed that NPM1 co-expressed genes involved in a variety of biological functions. NPM1 expression is potentially associated with a variety of immune cell infiltration, m6A and cuproptosis related genes in gastrointestinal cancers.

Conclusion: NPM1 can be used as a diagnostic and prognostic marker of gastrointestinal cancer, which is related to the immune cell infiltration and the regulation of m6A and cuproptosis.

Identification and validation of a metabolism-related gene signature for the prognosis of colorectal cancer: a multicenter cohort study

OBJECTIVE

Cell metabolism plays a vital role in the proliferation, metastasis and sensitivity to chemotherapy drugs of colorectal cancer. The purpose of this multicenter cohort study is to investigate the potential genes indicating clinical outcomes in colorectal cancer patients.

METHODS

We analyzed gene expression profiles of colorectal cancer to identify differentially expressed genes then used these differentially expressed genes to construct prognostic signature based on the least absolute shrink-age and selection operator Cox regression model. In addition, the multi-gene signature was validated in independent datasets including our multicenter cohort. Finally, nomograms were set up to evaluate the prognosis of colorectal cancer patients.

RESULTS

Seventeen metabolism-related genes were determined in the least absolute shrink-age and selection operator model to construct signature, with area under receiver operating characteristic curve for relapse-free survival, 0.741, 0.755 and 0.732 at 1, 3 and 5 year, respectively. External validation datasets, GSE14333, GSE37892, GSE17538 and the Cancer Genome Atlas cohorts, were analyzed and stratified, indicating that the metabolism-related signature was reliable in discriminating high- and low-risk colorectal cancer patients. Area under receiver operating characteristic curves for relapse-free survival in our multicenter validation cohort were 0.801, 0.819 and 0.857 at 1, 3 and 5 year, respectively. Nomograms incorporating the genetic biomarkers and clinical pathological features were set up, which yielded good discrimination and calibration in the prediction of prognosis for colorectal cancer patients.

CONCLUSION

An original metabolism-related signature was developed as a predictive model for the prognosis of colorectal cancer patients. A nomogram based on the signature was advantageous to facilitate personalized counselling and treatment of colorectal cancer patients.

Inverse Molecular Docking Elucidating the Anticarcinogenic Potential of the Hop Natural Product Xanthohumol and Its Metabolites

Natural products from plants exert a promising potential to act as antioxidants, antimicrobials, anti-inflammatory, and anticarcinogenic agents. Xanthohumol, a natural compound from hops, is indeed known for its anticarcinogenic properties. Xanthohumol is converted into three metabolites: isoxanthohumol (non-enzymatically) as well as 8- and 6-prenylnaringenin (enzymatically). An inverse molecular docking approach was applied to xanthohumol and its three metabolites to discern their potential protein targets. The aim of our study was to disclose the potential protein targets of xanthohumol and its metabolites in order to expound on the potential anticarcinogenic mechanisms of xanthohumol based on the found target proteins. The investigated compounds were docked into the predicted binding sites of all human protein structures from the Protein Data Bank, and the best docking poses were examined. Top scoring human protein targets with successfully docked compounds were identified, and their experimental connection with the anticarcinogenic function or cancer was investigated. The obtained results were carefully checked against the existing experimental findings from the scientific literature as well as further validated using retrospective metrics. More than half of the human protein targets of xanthohumol with the highest docking scores have already been connected with the anticarcinogenic function, and four of them (including two important representatives of the matrix metalloproteinase family, MMP-2 and MMP-9) also have a known experimental correlation with xanthohumol. Another important protein target is acyl-protein thioesterase 2, to which xanthohumol, isoxanthohumol, and 6-prenylnaringenin were successfully docked with the lowest docking scores. Moreover, the results for the metabolites show that their most promising protein targets are connected with the anticarcinogenic function as well. We firmly believe that our study can help to elucidate the anticarcinogenic mechanisms of xanthohumol and its metabolites as after consumption, all four compounds can be simultaneously present in the organism.

MicroRNA-545-5p regulates apoptosis, migration and invasion of osteosarcoma by targeting dimethyladenosine transferase 1

The metastasis of osteosarcoma is a major threat to both adolescents and young adults. Identifying novel targets that may prevent osteosarcoma metastasis is critical in developing advanced clinical therapies for treating this cancer. The present study aimed to explore the mechanism of microRNA (miR)-545-5p in the metastasis of osteosarcoma. The present study identified miR-545-5p as a potential target that was downregulated in both osteosarcoma clinical samples and cell lines, and in the latter, ectopically expressed miR-545-5p caused apoptosis. In addition, miR-545-5p exerted inhibitory effects in osteosarcoma migration and invasion. Overexpression of miR-545-5p induced xenograft growth inhibition in vivo. In addition, miR-545-5p targeted dimethyladenosine transferase 1 (DIMT1), an oncogenic protein that facilitates osteosarcoma proliferation, migration and invasion. Taken together, the results of the present study suggest that miR-545-5p functions as a tumor suppressor in osteosarcoma that promotes apoptosis, while inhibiting migration and invasion by targeting DIMT1. Taken together, the results of the present study suggest two potential novel targets for osteosarcoma treatment and metastasis prevention.

Rare CNVs provide novel insights into the molecular basis of GH and IGF-1 insensitivity

OBJECTIVE

Copy number variation (CNV) has been associated with idiopathic short stature, small for gestational age and Silver-Russell syndrome (SRS). It has not been extensively investigated in growth hormone insensitivity (GHI; short stature, IGF-1 deficiency and normal/high GH) or previously in IGF-1 insensitivity (short stature, high/normal GH and IGF-1).

DESIGN AND METHODS

Array comparative genomic hybridisation was performed with ~60 000 probe oligonucleotide array in GHI (n = 53) and IGF-1 insensitivity (n = 10) subjects. Published literature, mouse models, DECIPHER CNV tracks, growth associated GWAS loci and pathway enrichment analyses were used to identify key biological pathways/novel candidate growth genes within the CNV regions.

RESULTS

Both cohorts were enriched for class 3-5 CNVs (7/53 (13%) GHI and 3/10 (30%) IGF-1 insensitivity patients). Interestingly, 6/10 (60%) CNV subjects had diagnostic/associated clinical features of SRS. 5/10 subjects (50%) had CNVs previously reported in suspected SRS: 1q21 (n = 2), 12q14 (n = 1) deletions and Xp22 (n = 1), Xq26 (n = 1) duplications. A novel 15q11 deletion, previously associated with growth failure but not SRS/GHI was identified. Bioinformatic analysis identified 45 novel candidate growth genes, 15 being associated with growth in GWAS. The WNT canonical pathway was enriched in the GHI cohort and CLOCK was identified as an upstream regulator in the IGF-1 insensitivity cohorts.

CONCLUSIONS

Our cohort was enriched for low frequency CNVs. Our study emphasises the importance of CNV testing in GHI and IGF-1 insensitivity patients, particularly GHI subjects with SRS features. Functional experimental evidence is now required to validate the novel candidate growth genes, interactions and biological pathways identified.