Identification of novel SNPs in differentially expressed genes and its association with horn cancer of Bos indicus bullocks by next-generation sequencing

Understanding of molecular basis of histological graded horn cancer by transcriptome profiling

Horn cancer is most devastating and prominent cancer in Indian zebu cattle that affects socio-economic condition of small-scale farmers who depends on their cattle for farm work. Development in the field for genomics through next generation sequencing and bioinformatics advancement have helped to identify genes which have a role in horn cancer development. Histopathological examination of cancerous tissues of horn revealed myxomatous changes, well, moderate and poorly differentiated squamous cell carcinoma. Differential gene expression analysis showed 40, 11, 66 and 29 upregulated genes and 10, 14, 08 and 07 down-regulated genes in myxomatous, well, moderate and poorly differentiated squamous cell carcinoma as compared to normal. Significant differentially expressed genes are related to cell development, cell proliferation, cell-cell communication, cell signaling and angiogenesis which are linked to Akt pathway, mTOR pathway and Wnt pathway. Activity of these genes and related pathways have already been established about their role in development of cancer. Among the candidate genes; keratin family, keratin family related gene, chemokine signaling and cytokines signaling associated genes could be a prominent target for the development of stage specific prognosis marker after further detailed study at large sample population level. CSTA, PTN, SPP1 genes have upregulation in all stages of cancer and they have enrolled as biomarkers for horn cancer.

Molecular portrait of squamous cell carcinoma of the bovine horn evaluated by high-throughput targeted exome sequencing: a preliminary report

Background

Squamous Cell Carcinoma of horn, also known as horn cancer, is a prevailing type of cancer in cattles especially Bos indicus. It is one of the most prevalent disease in Indian bullocks often resulting in death and huge economic losses to farmers. Here, we have reported the use of targeted exome sequencing to identify variants present in horn cancer affected horn mucosa tissue and blood of the same animal to identify some of the prevalent markers of horn cancer.

Results

We have observed higher number of variants present in tissue as compared to blood as well as among cancer samples compared to samples from normal animals. Eighty six and 1437 cancer-specific variants were identified among the predicted variants in blood and tissue samples, respectively. Total 25 missense variants were observed distributed over 18 genes. KRT8 gene coding for Keratin8, one of the key constituents of horn, displayed 5 missense variants. Additionally, three other genes involved in apoptosis pathway and two genes involved in antigen presentation and processing also contained variants.

Conclusions

Several genes involved in various apoptotic pathways were found to contain non-synonymous mutations. Keratin8 coding for Keratin, a chief constituent of horn was observed to have the highest number of mutations. In all, we present a preliminary report of mutations observed in horn cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-020-02683-y.

p53 Gene Mutation in Blood of Zebu Cattle with Squamous Cell Carcinoma of the Horn

Horn cancer is one of the most important diseases in Zebu castrated male cattle. The objective of this study was to investigate the presence of p53 gene mutation in the blood of affected cattle and its value for early diagnosis and prognosis. The study was conducted on blood samples from 20 affected cattle and six healthy control cattle from Western India. Plasma samples were evaluated for the presence of p53 gene mutation using the polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) technique and the results were correlated with the stage of cancer. Five of the 20 cases had stage I neoplasms, nine stage II and six stage III, based on histopathological examination. PCR-SSCP analysis revealed an aberrant pattern of DNA migration on polyacrylamide gel electrophoresis of DNA extracts from blood samples of six animals with stage II and stage III cancer. No mutation was identified in blood from cattle with stage I cancer or from healthy control cattle. These results suggest that PCR-SSCP detection of p53 gene mutation in blood has potential diagnostic and prognostic value, and indicate the need for further large-scale investigation.