Background: Ovarian cancer (OC) is the most common type of gynecological malignant tumors with poor prognosis. The spen paralogue and orthologue C-terminal domain containing 1 (SPOCD1) is a newly identified molecule that has been indicated to discriminate progressive in human solid tumors. However, the role of SPOCD1 in OC remains unknown. Methods: The expression of SPOCD1 in OC and non-cancerous tissue was detected by Realtime polymerase chain reaction and immunohistochemical staining. The expression of SPOCD1 in OC cells (SKOV3 and CAOV3) was also detected by immunohistochemical staining. The effect of SPOCD1 on cell proliferation was analyzed by Cell Counting Kit 8 and colony formation assay, and cell migration was analyzed by transwell assay. Apoptosis was analyzed by flow cytometry. The protein expression of SPOCD1, PTEN, PI3K, p-AKT, and mTOR in OC cells was measured by Western blot. Results: SPOCD1 expression was significantly upregulated in OC tissues compared with non-cancerous tissues (P<0.01), and was positively correlated to FIGO stage and tumor grade of OC. Also, SPOCD1 was significantly expressed in nucleus and cytoplasm of SKOV3 and CAOV3 cells. Kaplan-Meier analysis indicated that patients with high SPOCD1 expression had shorter overall survival (HR =1.512, 95%CI: 1.321-2.793, P=0.031) and progression-free survival (HR =1.875, 95%CI: 1.435-3.157, P=0.028). SPOCD1 was upregulated in OC SKOV3 and CAOV3 cells. Further investigation revealed that downregulation of SPOCD1 inhibited the SKOV3 and CAOV3 cells proliferation and migration. In addition, the deficit of SPOCD1 increased the apoptosis in SKOV3 and CAOV3 cells. PI3K/AKT pathway was inhibited by knockdown of SPOCD1 in SKOV3 and CAOV3 cells. Conclusions: Our data suggest that SPOCD1 may act as a carcinogenesis factor by activating the PI3K/AKT pathway to restrained cell apoptosis in OC.

Background The filamentous fungus Trichoderma reesei is extensively used for the industrial-scale cellulase production. It has been well known that the transcription factor Xyr1 plays an important role in the regulatory network controlling cellulase gene expression. However, the role of Xyr1 in the regulation of cellulase expression has not been comprehensively elucidated, which hinders further improvement of lignocellulolytic enzyme production. Results Here, the expression dosage of xyr1 was tailored in T. reesei by differentially overexpressing the xyr1 gene under the control of three strong promoters (Pegl2, Pcbh1, and Pcdna1), and the transcript abundance of xyr1 was elevated 5.8-, 12.6-, and 47.2-fold, respectively. We found expression of cellulase genes was significantly increased in the Pegl2-driven xyr1 overexpression strain QE2X, whereas relatively low in the Pcbh1- and Pcdna1-driven overexpression strains. We also found that the Pegl2-driven overexpression of xyr1 caused a more significant opening of chromatin in the core promoter region of the prominent cellulase genes. Furthermore, the cellulase activity showed a 3.2-fold increase in the strain QE2X, while insignificant improvement in the Pcbh1- and Pcdna1-driven strains. Finally, the saccharification efficiency toward acid-pretreated corncob residues containing high-content lignin by the crude enzyme from QE2X was increased by 57.2% compared to that from the parental strain. Moreover, LC–MS/MS and RT-qPCR analysis revealed that expression of accessory proteins (Cip1, Cip2, Swo1, and LPMOs) was greatly improved in QE2X, which partly explained the promoting effect of the Pegl2-driven overexpression on enzymatic hydrolysis of lignocellulose biomass. Conclusions Our results underpin that the precise tailoring expression of xyr1 is essential for highly efficient cellulase synthesis, which provide new insights into the role of Xyr1 in regulating cellulase expression in T. reesei. Moreover, these results also provides a prospective strategy for strain improvement to enhance the lignocellulolytic enzyme production for use in biorefinery applications.

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