Jian Zheng

Single-cell transcriptomic analysis deciphers heterogenous cancer stem-like cells in colorectal cancer and their organ-specific metastasis

Objective Metastasis is the major cause of cancer death. However, what types of heterogenous cancer cells in primary tumour and how they metastasise to the target organs remain largely undiscovered. Design We performed single-cell RNA sequencing and spatial transcriptomic analysis in primary colorectal cancer (CRC) and metastases in the liver (lCRC) or ovary (oCRC). We also conducted immunofluorescence staining and functional experiments to examine the mechanism. Results Integrative analyses of epithelial cells reveal a stem-like cell cluster with high protein tyrosine phosphatase receptor type O ( PTPRO ) and achaete scute-like 2 ( ASCL2 ) expression as the metastatic culprit. This cell cluster comprising distinct subpopulations shows distinct liver or ovary metastatic preference. Population 1 (P1) cells with high delta-like ligand 4 (DLL4) and MAF bZIP transcription factor A (MAFA) expression are enriched in primary CRC and oCRC, thus may be associated with ovarian metastasis. P3 cells having a similar expression pattern as cholangiocytes are found mainly in primary CRC and lCRC, presuming to be likely the culprits that specifically metastasise to the liver. Stem-like cells interacted with cancer-associated fibroblasts and endothelial cells via the DLL4-NOTCH signalling pathway to metastasise from primary CRC to the ovary. In the oCRC microenvironment, myofibroblasts provide cancer cells with glutamine and perform a metabolic reprogramming, which may be essential for cancer cells to localise and develop in the ovary. Conclusion We uncover a mechanism for organ-specific CRC metastasis.

Detection of DKK-1 gene methylation in exfoliated cells of cervical squamous cell carcinoma and its relationship with high risk HPV infection

To detect the methylation of Dickkopf-associated protein 1 (DKK-1) gene promoter in cervical exfoliated cells and to study its clinical significance in cervical squamous cell carcinoma (CSCC) and its relationship with high-risk HPV infection. Methylation-specific PCR (MSP) was utilized to detect the methylation of DKK-1 gene promoter in cervical exfoliated cells from 40 patients with CSCC and 40 patients with chronic cervicitis in the Affiliated Hospital of Inner Mongolia Medical University. The methylation rate of DKK-1 gene promoter in different clinicopathological factors and its relationship with high-risk HPV infection was compared, and different detection methods were compared. The degree of methylation of DKK-1 gene promoter in CSCC group was significantly higher than that in cervicitis group (P  0.05). The one-year survival rate of CSCC patients with high-risk HPV positive and DKK-1 gene promoter methylation is relatively low, only 74.1%. The sensitivity, specificity and accuracy of DKK-1 gene methylation combined with high-risk HPV detection were 96.7%, 78.0% and 85.0%, respectively. Methylation of DKK-1 gene promoter in cervical exfoliated cells of patients with CSCC is related to high-risk HPV infection and different clinicopathological factors, but the degree of methylation of DKK-1 gene is not related to the type of high-risk HPV infection. It may become an indicator different from HPV typing detection, which may play a shunt role in suggesting whether further invasive cervical examination is needed and reduce cervical invasive examination and overtreatment. It may be related to the survival rate of patients, which can be used to estimate the development and prognosis of CSCC and may play a good role in early warning in follow-up monitoring of CSCC after treatment. DKK1 gene methylation combined with HPV detection can improve the sensitivity, specificity and accuracy of diagnosis, which may improve the detection rate of early CSCC and make up for the deficiency of HPV and TCT detection. That may become a non-invasive screening method for CSCC.