Clinical Performance of Friend Leukemia Virus Integration 1 Methylation as a Biomarker for Colorectal Carcinoma

Objectives Accumulating evidence supports the reliability of molecular biomarkers and cancer, the current situation is lacking. This present study was aimed to investigate clinical performance of friend leukemia virus integration 1 (FLI1) methylation as a biomarker for colorectal cancer (CRC). Methods The datasets of UALCAN, GEPIA, cBioPortal, STRING, TIMER2.0, GEO, and KOBAS were utilized in this present study. In order to testify the methylation function of FLI1 in CRC, we studied 6 CRC cell lines and 20 pairs of tumor tissues. The transcriptional levels of FLI1 were tested by reverse transcription PCR quantitatively and western blot. Cell viability, transwell assays and plate clone assay were utilized to assess the cell function. Results FLI1 was up-regulated in the GBM, KIRC, LAML, etc. Meanwhile, it was down-regulated in BLCA, BRCA, CESC, etc (p<0.05). The CPTAC dataset showed higher total protein in the primary tissues of KIRC, lower protein in the BRCA, OV, LUAD, UCEC than normal tissues(p<0.05). Highly expressed FLI1 was linked to poor prognosis of overall survival (OS) in LGG, UVM (p<0.05). Low expression of FLI1 was associated with short OS in KIRC, LUAD, SKCM (p<0.05). Compared with normal tissues, the methylation level of FLI1 was increased in BRCA, CESC, CHOL, COAD, etc (p<0.05). In the contrary, it was decreased in KIRP, PCPG obviously (p<0.05). Moreover, it showed a reduced phosphorylation for selected probes (BRCA: NP_002008.2:S39, NP_002008.2:S3241; OV: NP_002008.2:S39; LUAD: NP_002008.2:S79, NP_002008.2:S3241; all p<0.05). Meanwhile, it showed an enhanced phosphorylation level of FLI1 in KIRC for selected probes (NP_002008.2:S241, p<0.05). Besides, a statistical negative correlation was found between FLI1 and Treg cells, neutrophils, monocytes, macrophages, NK cells, cancer-associated fibroblasts, and common immune checkpoint gene levels (p<0.05). Besides, in vivo experience showed that 5-Aza-2’-deoxycytidine diminished FLI1 methylation level and restored transcriptional levels (p>0.05) in CRC. In vitro experiments demonstrated that the proliferation, colony formation, invasion and migration of CRC cells were inhibited by FLI1 overexpression through FMNL1 (p<0.05). Conclusions This present study offers a comprehensive understanding of FLI1 in carcinomas with oncogenesis and immunotherapeutic implications. Moreover, FLI1 reduced the proliferation, colony formation, invasion and migration of CRC by FMNL1.

Successful Radical Pneumonectomy for a Primitive Neuroendodermal Tumor in the Lung: A Case Report and Review of the Literature

Peripheral primitive neuroendodermal tumors (PNETs) and Ewing's sarcoma belong to the Ewing family of tumors and are small round-cell malignancies originating from spinal cord cells. These tumors account for 5% of all small round-cell malignant neoplasms. PNETs that arise from the lung parenchyma without pleural or chest wall involvement are very rare. We report a case of an adult female with a large pulmonary PNET who had given birth just 1 month prior to the diagnosis. She had cough and expectoration for 6 months, and the preoperative examination showed no metastases. Thus, we performed radical pneumonectomy and lymph node dissection. The patient recovered well without surgical complications and was discharged 7 days after the surgery. Postoperative pathology confirmed that the tumor was a small round-cell malignancy, and the tumor cells were positive for CD99, Friend leukemia virus integration 1 (FLI-1), and neuron-specific enolase (NSE), which was consistent with the diagnosis of a PNET. For primary large pulmonary PNETs, radical pneumonectomy may be a safe surgical method, worthy of further application in clinical practice.

What can we learn from Fli1-deficient mice, new animal models of systemic sclerosis?

Systemic sclerosis is a complex multifactorial disease characterized by autoimmunity, vasculopathy, and selective organ fibrosis. A series of genetic and epidemiological studies have demonstrated that environmental influences play a central role in the onset of systemic sclerosis, while genetic factors determine the susceptibility to and the severity of this disease. Therefore, the identification of predisposing factors related to environmental influences would provide us with an informative clue to better understand the pathological process of this disease. Based on this concept, the deficiency of transcription factor Friend leukemia virus integration 1, which is epigenetically suppressed in systemic sclerosis, seems to be a potential candidate acting as the predisposing factor of this disease. Indeed, Fli1-mutated mice serve as a set of useful disease models to disclose the complex pathology of systemic sclerosis. This article overviews the recent advancement in systemic sclerosis animal models associated with Friend leukemia virus integration 1 deficiency.

Epithelial Fli1 deficiency drives systemic autoimmunity and fibrosis: Possible roles in scleroderma

Systemic sclerosis (SSc), or scleroderma, is a multisystem autoimmune disorder characterized by vasculopathy and fibrosis in the skin and internal organs, most frequently in the esophagus and lungs. Hitherto, studies on SSc pathogenesis centered on immune cells, vascular cells, and fibroblasts. Although dysregulated keratinocytes in SSc have been recently reported, the contribution of epithelial cells to pathogenesis remains unexplored. In this study, we demonstrated the induction of SSc-like molecular phenotype in keratinocytes by gene silencing of transcription factor Friend leukemia virus integration 1 (Fli1), the deficiency of which is implicated in SSc pathogenesis. Keratin 14–expressing epithelial cell–specific Fli1 knockout mice spontaneously developed dermal and esophageal fibrosis with epithelial activation. Furthermore, they developed remarkable autoimmunity with interstitial lung disease derived from thymic defects with down-regulation of autoimmune regulator (Aire). Importantly, Fli1 directly regulated Aire expression in epithelial cells. Collectively, epithelial Fli1 deficiency might be involved in the systemic autoimmunity and selective organ fibrosis in SSc. This study uncovers unidentified roles of dysregulated epithelial cells in SSc pathogenesis.