Role of Alpha-Smooth Muscle Actin and Fibroblast Activation Protein Alpha in Ovarian Neoplasms

Cutaneous Metastasis of Ovarian Cancer on 68 Ga-FAPI PET/CT

ABSTRACT

Ovarian cancer with cutaneous metastases is quite rare. We report the findings of cutaneous metastases from ovarian cancer on 68 Ga-FAPI PET/CT imaging. A 53-year-old woman with cutaneous metastases from ovarian cancer was enrolled in 68 Ga-FAPI PET/CT clinical trial. The images showed intense FAPI activity in the known cutaneous metastases.

Fibroblast activation protein: Pivoting cancer/chemotherapeutic insight towards heart failure

An important mechanism for cancer progression is degradation of the extracellular matrix (ECM) which is accompanied by the emergence and proliferation of an activated fibroblast, termed the cancer associated fibroblast (CAF). More specifically, an enzyme pathway identified to be amplified with local cancer progression and proliferation of the CAF, is fibroblast activation protein (FAP). The development and progression of heart failure (HF) irrespective of the etiology is associated with left ventricular (LV) remodeling and changes in ECM structure and function. As with cancer, HF progression is associated with a change in LV myocardial fibroblast growth and function, and expresses a protein signature not dissimilar to the CAF. The overall goal of this review is to put forward the postulate that scientific discoveries regarding FAP in cancer as well as the development of specific chemotherapeutics could be pivoted to target the emergence of FAP in the activated fibroblast subtype and thus hold translationally relevant diagnostic and therapeutic targets in HF.

FAP is critical for ovarian cancer cell survival by sustaining NF-κB activation through recruitment of PRKDC in lipid rafts

Fibroblast activation protein (FAP) is tumor-specific and plays an important role in tumorigenecity. However, agents against its enzymatic activity or extracellular presence were unsuccessful in the clinic for undefined reasons. Here we show that FAP expression is higher in advanced ovarian cancer and is only detected in invasive ovarian cancer cells. Silencing FAP induces apoptosis and FAP's enzymatic activity is dispensable for cell survival. To elucidate the cause of apoptosis, we find that NF-κB activity is diminished when FAP is depleted and BIRC5 (survivin) acts downstream of FAP-NF-κB axis to promote cell survival. To uncover the link between FAP and NF-κB activation, we reveal that PRKDC (DNA-PK, DNA-dependent protein kinase) forms complex with FAP and is required for NF-κB activation and cell survival. Remarkably, FAP-PRKDC interaction occurs only in lipid rafts, and depleting FAP prevents lipid raft localization of PRKDC. Given the known ability of PRKDC to direct NF-κB activation, these results suggest that FAP recruits PRKDC in lipid rafts for NF-κB activation. FAP's non-enzymatic role and functioning from lipid rafts for cell survival also offer an explanation on the failure of past FAP-targeted therapies. Finally, we demonstrate that EpCAM aptamer-delivered FAP siRNA impeded intraperitoneal xenograft development of ovary tumors.

Pre-diagnosis meat intake and cooking method and ovarian cancer survival: results from the Ovarian Cancer Follow-Up Study (OOPS)

Objectives: The relationships between pre-diagnosis meat intake and ovarian cancer (OC) survival were limited and controversial. To date, no study has taken account of cooking methods. Thus, we aimed to firstly clarify these associations based on the Ovarian Cancer Follow-Up Study. Methods: This prospective cohort study, including 853 OC patients between 2015 and 2020, was conducted to examine the aforementioned associations. All women completed a food frequency questionnaire. Deaths were ascertained up to March 31, 2021 via medical records and active follow-up. We used the Cox proportional hazards model to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). Results: During the median follow-up of 37.17 months, 130 women died. Pre-diagnosis fish and seafood intake was associated with better survival (HR_{T3 vs. T1} = 0.46, 95% CI = 0.26-0.82, p trend <0.05), whereas processed red meat (HR = 1.54, 95% CI = 1.04-2.26) and a high frequency of fried fish intake (HR = 1.49, 95% CI = 1.03-2.16) were associated with worse survival than consuming none. After considering the interaction of cooking methods, we found that compared with the lowest tertile of fish and seafood intake and almost no fried fish cooking, women with the highest tertile of intake and almost no fried fish cooking had better survival (HR = 0.35, 95% CI = 0.13-0.92). Additionally, compared with the lowest tertile of fish and seafood intake and almost no baked fish cooking, women with the lowest tertile of intake and consuming baked fish had worse survival (HR = 3.75, 95% CI = 1.53-9.15). Conclusions: Pre-diagnosis fish and seafood intake was associated with better OC survival, whereas processed red meat intake was associated with worse survival. Cooking methods, especially for fried or baked fish, may play interaction effects with fish intake on OC survival.

Research Progress on Dipeptidyl Peptidase Family: Structure, Function and Xenobiotic Metabolism

Prolyl-specific peptidases or proteases, including Dipeptidyl Peptidase 2, 4, 6, 8, 9, 10, Fibroblast Activation Protein, prolyl endopeptidase and prolyl carboxypeptidase, belong to the dipeptidyl peptidase family. In human physiology and anatomy, they have homology amino acid sequences, similarities in structure, but play distinct functions and roles. Some of them also play important roles in the metabolism of drugs containing endogenous peptides, xenobiotics containing peptides, and exogenous peptides. The major functions of these peptidases in both the metabolism of human health and bioactive peptides are of significant importance in the development of effective inhibitors to control the metabolism of endogenous bioactive peptides. The structural characteristics, distribution of tissue, endogenous substrates, and biological functions were summarized in this review. Furthermore, the xenobiotics metabolism of the dipeptidyl peptidase family is illustrated. All the evidence and information summarized in this review would be very useful for researchers to extend the understanding of the proteins of these families and offer advice and assistance in physiology and pathology studies.

Colorectal cancer cell intrinsic fibroblast activation protein alpha binds to Enolase1 and activates NF-κB pathway to promote metastasis

Fibroblast activation protein alpha (FAP) is a marker of cancer-associated fibroblast, which is also expressed in cancer epithelial cells. However, the role of FAP in colorectal cancer (CRC) cells remains to be elucidated. Here we investigate the expression pattern of FAP in CRC tissues and cells to prove that FAP is upregulated in CRC cells. Loss- of and gain-of-function assays identified FAP promotes migration and invasion instead of an effect on cell proliferation. Microarray assays are adopted to identify the different expressed genes after FAP knockdown and gene set enrichment analysis (GSEA) is used to exploit the involved signaling pathway. Our works reveal FAP exerts a function dependent on NF-κB signaling pathway and FAP expression is associated with NF-κB signaling pathway in clinical samples. Our work shows FAP is secreted by CRC cells and soluble FAP could promote metastasis. To investigate the mechanism of FAP influencing the NF-κB signaling pathway, LC/MS is performed to identify the proteins interacting with FAP. We find that FAP binds to ENO1 and activates NF-κB signaling pathway dependent on ENO1. Blocking ENO1 could partially reverse the pro-metastatic effect mediated by FAP. We also provide evidences that both FAP and ENO1 are associated with CRC stages, and high levels of FAP and ENO1 predict a poor survival in CRC patients. In summary, our work could provide a novel mechanism of FAP in CRC cells and a potential strategy for treatment of metastatic CRC.

The Role of Stroma in Ovarian Cancer

Background: Ovarian cancer is one of the gynecological malignancies responsible for thousands of deaths in women worldwide. Malignant solid tumors are formed by malignant cells and stroma that influence each other, where different types of cells in the stromal environment can be recruited by malignant cells to promote tumor growth and facilitate metastasis. The chronic inflammatory response is increasingly accepted in its relation to the pathophysiology of the onset and development of tumors, sustained cell proliferation in an environment rich in inflammatory cells, growth factors, activated stroma and DNA damage agents may increase the risk to develop a neoplasm.Methods: A search for the following keywords was performed in the PubMed database; "Ovarian cancer", "stroma", "tumor-associated macrophages", "cancer-associated fibroblasts", "cytokines", "angiogenesis", "epithelial-mesenchymal transition", and "extracellular matrix".Results: The articles identified were published in English between 1971 and 2018. A total of 154 articles were selected for further analysis. Conclusion: We consider ovarian cancer as a heterogeneous disease, not only in the sense that different histological or molecular subtypes may be behind the same clinical result, but also that multiple cell types besides cancer cells, like other non-cellular components, need to be mobilized and coordinated to support tumor survival, growth, invasion and progression.