Single-cell sequencing highlights heterogeneity and malignant progression in actinic keratosis and cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most frequent of the keratinocyte-derived malignancies with actinic keratosis (AK) as a precancerous lesion. To comprehensively delineate the underlying mechanisms for the whole progression from normal skin to AK to invasive cSCC, we performed single-cell RNA sequencing (scRNA-seq) to acquire the transcriptomes of 138,982 cells from 13 samples of six patients including AK, squamous cell carcinoma in situ (SCCIS), cSCC, and their matched normal tissues, covering comprehensive clinical courses of cSCC. We identified diverse cell types, including important subtypes with different gene expression profiles and functions in major keratinocytes. In SCCIS, we discovered the malignant subtypes of basal cells with differential proliferative and migration potential. Differentially expressed genes (DEGs) analysis screened out multiple key driver genes including transcription factors along AK to cSCC progression. Immunohistochemistry (IHC)/immunofluorescence (IF) experiments and single-cell ATAC sequencing (scATAC-seq) data verified the expression changes of these genes. The functional experiments confirmed the important roles of these genes in regulating cell proliferation, apoptosis, migration, and invasion in cSCC tumor. Furthermore, we comprehensively described the tumor microenvironment (TME) landscape and potential keratinocyte-TME crosstalk in cSCC providing theoretical basis for immunotherapy. Together, our findings provide a valuable resource for deciphering the progression from AK to cSCC and identifying potential targets for anticancer treatment of cSCC.

Prediction of Small Molecule-MicroRNA Associations by Sparse Learning and Heterogeneous Graph Inference.

As microRNAs (miRNAs) have been reported to be a type of novel high-value small molecule (SM) drug targets for disease treatments, many researchers are engaged in the field of exploring new SM-miRNA associations. Nevertheless, because of the high cost, adopting traditional biological experiments constrains the efficiency of discovering new associations between SMs and miRNAs. Therefore, as an important auxiliary tool, reliable computational models will be of great help to reveal SM-miRNA associations. In this article, we developed a computational model of sparse learning and heterogeneous graph inference for small molecule-miRNA association prediction (SLHGISMMA). Initially, the sparse learning method (SLM) was implemented to decompose the SM-miRNA adjacency matrix. Then, we integrated the reacquired association information together with the similarity information of SMs and miRNAs into a heterogeneous graph to infer potential SM-miRNA associations. Here, the main innovation of SLHGISMMA lies in the introduction of SLM to eliminate noises of the original adjacency matrix to some extent, which plays an important role in performance improvement. In addition, to assess SLHGISMMA' performance, four different kinds of cross-validations were performed based on two datasets. As a result, based on dataset 1 (dataset 2), SLHGISMMA achieved area under the curves of 0.9273 (0.7774), 0.9365 (0.7973), 0.7703 (0.6556), and 0.9241 ± 0.0052 (0.7724 ± 0.0032) in global leave-one-out cross-validation (LOOCV), miRNA-fixed local LOOCV, SM-fixed local LOOCV, and 5-fold cross-validation, respectively. Moreover, in the case study on three important SMs via removing their known associations, the results showed that most of the top 50 predicted miRNAs were confirmed by the database SM2miR v1.0 or the experimental literature.

Computational models for lncRNA function prediction and functional similarity calculation.

From transcriptional noise to dark matter of biology, the rapidly changing view of long non-coding RNA (lncRNA) leads to deep understanding of human complex diseases induced by abnormal expression of lncRNAs. There is urgent need to discern potential functional roles of lncRNAs for further study of pathology, diagnosis, therapy, prognosis, prevention of human complex disease and disease biomarker detection at lncRNA level. Computational models are anticipated to be an effective way to combine current related databases for predicting most potential lncRNA functions and calculating lncRNA functional similarity on the large scale. In this review, we firstly illustrated the biological function of lncRNAs from five biological processes and briefly depicted the relationship between mutations or dysfunctions of lncRNAs and human complex diseases involving cancers, nervous system disorders and others. Then, 17 publicly available lncRNA function-related databases containing four types of functional information content were introduced. Based on these databases, dozens of developed computational models are emerging to help characterize the functional roles of lncRNAs. We therefore systematically described and classified both 16 lncRNA function prediction models and 9 lncRNA functional similarity calculation models into 8 types for highlighting their core algorithm and process. Finally, we concluded with discussions about the advantages and limitations of these computational models and future directions of lncRNA function prediction and functional similarity calculation. We believe that constructing systematic functional annotation systems is essential to strengthen the prediction accuracy of computational models, which will accelerate the identification process of novel lncRNA functions in the future.