Single-Cell RNA Sequencing Reveals Transcriptional Changes in the Cartilage of Subchondral Insufficiency Fracture of the Knee.

Purpose: Subchondral insufficiency fracture of the knee (SIFK) is a common cause of knee joint pain that mainly afflicts the elderly. Until now, how a sudden insufficiency fracture of subchondral bone affects the transcriptomic profiles of cartilage in SIFK and OA patients are largely unknown. Methods: Single-cell RNA sequencing (scRNA-seq) was used to identify various cell subsets and evaluate transcriptomic differences in cartilage of SIFK and OA patients. In addition, the above findings were confirmed by histological evaluation and immunohistochemical (IHC) staining. Results: We found that the transcriptomic profiles of cartilage in the SIFK patient was completely different from those of normal and OA patients. Accordingly, several novel cell clusters with activation of hypoxia and endochondral ossification signaling were identified in the SIFK cartilage. Chondrocyte trajectories analysis and IHC staining revealed that transcription factors including TCF4 were found to be highly up-regulated during the occurrence of SIFK, which might drive the reactive formation of cartilage and fibrous tissue and the activation of endochondral ossification. Conclusion: This is the first report to elucidate the transcriptomic alterations and distinct cell type subpopulations in the cartilage of SIFK and OA by the use of scRNA-seq, which provides a new insight in the understanding of the initiation and progression of SIFK.

HLA-G impairs host immune response and predicts poor prognosis in pancreatic cancer.

Human leucocyte antigen G (HLA-G) was shown to be associated with immune suppression and unfavorable prognosis in multiple types of cancers. However, its expression in pancreatic cancer (PC) was less investigated. Particularly, its roles in PC remain unknown. The present study aimed to address the issues. Expression of HLA-G was detected by Western blot and tissue microarray-based immunohistochemical staining in 10 and 158 patients with PC, respectively. In addition, tumor infiltrating lymphocytes (TIL) labeled by CD3 staining, as a marker of host immune response, were counted. Finally, immunohistochemical HLA-G expression was linked to clinicopathologic variables, TIL number and overall survival. It was found that HLA-G was overexpressed in 4 out of 10 patients. For staining, HLA-G expression was much higher in tumor than in non-tumor tissues. Tumoral expression of HLA-G was closely associated with T stage. Intratumoral CD3-positive TIL in tumors with diffuse HLA-G expression was less than that in those with negative or local HLA-G expression, but no significant differences for stromal TIL were observed. Univariate analysis found that diffuse HLA-G expression in tumor tissues and low intratumoral CD3-positive TIL number were of predictive significance for poor overall survival of PC. Furthermore, HLA-G expression and intratumoral CD3-positive TIL number were identified, by multivariate Cox regression test, as independent prognostic factors. Our data suggest that HLA-G impairs host immune response and predicts poor prognosis in PC.

Changes in the Expression of Glucose-regulated Protein 78 in the Occurrence and Progression of Pancreatic Cancer in Mouse Models.

OBJECTIVE: To investigate the changes in the expression of glucose-regulated protein 78 (GRP78) in the occurrence and progression of pancreatic cancer in mouse models. METHODS: The mouse models of chronic pancreatitis,pancreatic intraepithelial neoplasia (PanIN), and pancreatic cancer were successfully established by dimethyl benzene and anthracene (DMBA) embedding in situ. GRP78 expression was detected in various stages by immunohistochemistry. RESULTS: Of these 60 mouse models, 18 mice (30%) died during the observation period. Two months after the embedding,the survived mice were sacrificed,and HE staining and IHC staining were performed. Among these mice, 9 (15%) developed chronic pancreatitis; 18 (30%) had PanIN [PanIN1,5 (8.3%);P anIN2,9 (15%); and PanIN 3,4 (6.7%)];15 (25%) developed pancreatic cancer. Immunohistochemistry showed that the expression of GRP78 in pancreatic cancer tissue was significantly higher than that in adjacent noncancerous duct cells (χ(2)=13.39,P =0.000). Also, GRP78 expression in pancreatic cancer tissue and high grade PanIN was significantly higher than that in low grade PanIN and chronic pancreatitis (χ(2)=17.84,P=0.000). CONCLUSION: The expression of GRP78 remarkably differs in different stages of pancreatic cancer and therefore is associated with the occurrence and progression of this disease.

Nuclear translocation of fibroblast growth factor receptor 3 and its significance in pancreatic cancer.

Nuclear translocation of fibroblast growth factor receptor 3 (FGFR3) was previously observed in some kinds of cancer. However, whether the phenomenon occurs in pancreatic cancer (PC), a malignancy with very dismal prognosis, remains unknown. In the present study, FGFR3 expression was firstly detected by Western blot and immunohistochemical staining in specimens of PC. Then, its correlations with clinicopathologic features and patient survival were evaluated. It was shown that FGFR3 was highly expressed in all the nuclear extracts, but in only one out of four whole tissue lysates, of tumor tissues, in contrast to those of non-tumor ones. Using immunohistochemistry, nuclear expression of FGFR3 was found to mainly locate in tumor cells, and was significantly associated with N stage. Furthermore, high FGFR3 nuclear expression was revealed to be associated with poor overall and disease-free survival in univariate analysis. For overall survival in the whole cohort and disease-free survival in patients with curative resection, high nuclear expression of FGFR3 was significant or marginally significant in multivariate analysis. However, its cytoplasmic expression was not related to clinical, pathologic variables and prognosis. These data suggest that nuclear translocation of FGFR3 is frequent and carries clinicopathologic as well as prognostic significances in PC.

Serum soluble ST2 is associated with ER-positive breast cancer.

BACKGROUND: ST2, a member of the interleukin (IL)-1receptor family, regulates Th1/Th2 immune responses in autoimmune and inflammatory conditions. However, the role of ST2 signaling in tumor growth and metastasis of breast cancers has not been investigated. This study investigated the possible role of soluble ST2 (sST2) in breast cancer. METHODS: The serum levels of IL-33, sST2, and vascular endothelial growth factor (VEGF) in 150 breast cancer patients and 90 healthy women were measured by enzyme-linked immunosorbent assay. Estrogen receptor(ER), progesterone receptor, human epithelial receptor (HER)-2, and cell cycle regulated protein Ki-67 were measured. Clinical stage, tumor size, lymph node metastasis, and histological type were also recorded. RESULTS: The serum levels of sST2, IL-33, and VEGF were significantly higher in breast cancer patients than in the control group (P < 0.05, each). Serum sST2 levels in ER-positive breast cancer patients were significantly associated with age, histological type, clinical stage, tumor size, and Ki-67 status (P < 0.05, each). Moreover, the serum levels of IL-33 and sST2 in breast cancers significantly correlated with VEGF levels (IL-33: r = 0.375, P < 0.0001; sST2: r = 0.164, P = 0.045). Serum levels of sST2, IL-33, and VEGF decreased after modified radical mastectomy in ER-positive breast cancers. Serum levels of IL-33, sST2, and VEGF and clinicopathological factors were not significantly correlated with disease-free survival and overall survival of ER-positive breast cancer women during follow-up. CONCLUSION: Serum sST2 levels in ER-positive breast cancer patients are significantly associated with factors that indicate poor prognosis.