Endogenous ether lipids differentially promote tumor aggressiveness by regulating the SK3 channel.

SK3 channels are potassium channels found to promote tumor aggressiveness. We have previously demonstrated that SK3 is regulated by synthetic ether lipids, but the role of endogenous ether lipids is unknown. Here, we have studied the role of endogenous alkyl- and alkenyl-ether lipids on SK3 channels and on the biology of cancer cells. Experiments revealed that the suppression of alkylglycerone phosphate synthase or plasmanylethanolamine desaturase 1, which are key enzymes for alkyl- and alkenyl-ether-lipid synthesis, respectively, decreased SK3 expression by increasing micro RNA (miR)-499 and miR-208 expression, leading to a decrease in SK3-dependent calcium entry, cell migration, and matrix metalloproteinase 9-dependent cell adhesion and invasion. We identified several ether lipids that promoted SK3 expression and found a differential role of alkyl- and alkenyl-ether lipids on SK3 activity. The expressions of alkylglycerone phosphate synthase, SK3, and miR were associated in clinical samples emphasizing the clinical consistency of our observations. To our knowledge, this is the first report showing that ether lipids differentially control tumor aggressiveness by regulating an ion channel. This insight provides new possibilities for therapeutic interventions, offering clinicians an opportunity to manipulate ion channel dysfunction by adjusting the composition of ether lipids.

Endocrine therapy in advanced high-grade ovarian cancer: real-life data from a multicenter study and a review of the literature.

BACKGROUND: In women, ovarian cancer is the eighth most frequent cancer in incidence and mortality. It is often diagnosed at advanced stages; relapses are frequent, with a poor prognosis. When platinum resistant, subsequent lines of chemotherapy are of limited effect and often poorly tolerated, leading to quality of life deterioration. Various studies suggest a hormonal role in ovarian carcinogenesis, with a rationale for endocrine therapy in these cancers. PATIENTS AND METHODS: This multicenter, retrospective study assessed the use of endocrine treatment for high-grade ovarian epithelial carcinomas treated between 2010 and 2020. RESULTS: Eighty-one patients with ovarian cancers were included. The median duration of platinum sensitivity was 29 months. We observed a 35% disease control rate with endocrine therapy, and 10% reported symptom improvement. For 19 patients (23.5%), the disease was stabilized for more than 6 months. Median overall survival from diagnosis was 62.6 months. Regarding endocrine therapy predictive factors of response, in a multivariate analysis, 3 factors were statistically significant in favoring progression-free survival: platinum sensitivity (P = .021), an R0 surgical resection (P = .020), and the indication for hormone therapy being maintenance therapy (P = .002). CONCLUSION: This study shows real-life data on endocrine therapy in ovarian cancer. As it is a low-cost treatment with many advantages such as its oral administration and its safety, it may be an option to consider. A perspective lies in the search for cofactors to aim as future therapeutic targets to improve the effectiveness of hormone treatment by means of combination therapy.

Contribution of the cadaveric recirculation system in the anatomical study of lymphatic drainage of the ovary: applications in the management of ovarian cancer.

PURPOSE: The present knowledge about lymphatic drainage of the ovary is based on carcinological studies, but it has only rarely been studied under physiological conditions. However, it is one of the preferential routes of dissemination in ovarian cancer, and understanding it is therefore vital for optimal carcinological management.Our purpose was to evaluate the feasibility of an innovative technique to study the lymphatic drainage territories of the ovary using a recirculation module on the cadaveric model. METHODS: We injected patent blue into the cortex of twenty "revascularised" cadaver ovaries with the Simlife recirculation model. We observed the migration of the dye live and described the drainage territories of each ovary. RESULTS: We observed a staining of the lymphatic vessels and migration of the dye in all the subjects, systematically ipsilateral to the injected ovary. We identified a staining of the lumbo-aortic territory in 65% of cases, with a preferential lateral-caval involvement (60%) for the right ovary and lateral-aortic territory (40%) for the left ovary. A common iliac involvement was observed in only 10% of cases. In 57% of cases, the staining of the lumbo-aortic territory was associated with a staining of the suspensory ligament. The pelvic territory was involved in 50% of cases, with an external iliac staining in 25% of cases and internal in 20%. CONCLUSION: Our study provides for a better understanding of lymphatic drainage of the ovary using a new detection method, and allows the possibility of improving the teaching for operators with a realistic model. Continuation of this work could lead to considering more targeted and thus less morbid lymph node sampling for lymph node staging in early-stage ovarian cancer.

Plasma membrane SK2 channel activity regulates migration and chemosensitivity of high-grade serous ovarian cancer cells.

No data are currently available on the functional role of small conductance Ca2+-activated K+ channels (SKCa) in ovarian cancer. Here, we characterized the role of SK2 (KCa2.2) in ovarian cancer cell migration and chemosensitivity. Using the selective non-cell-permeant SK2 inhibitor Lei-Dab7, we identified functional SK2 channels at the plasma membrane, regulating store-operated Ca2+ entry (SOCE) in both cell lines tested (COV504 and OVCAR3). Silencing KCNN2 with short interfering RNA (siRNA), or blocking SK2 activity with Lei-Dab7, decreased cell migration. The more robust effect of KCNN2 knockdown compared to Lei-Dab7 treatment suggested the involvement of functional intracellular SK2 channels in both cell lines. In cells treated with lysophosphatidic acid (LPA), an ovarian cancer biomarker of progression, SK2 channels are a key player of LPA pro-migratory activity but their role in SOCE is abolished. Concerning chemotherapy, SK2 inhibition increased chemoresistance to Taxol® and low KCNN2 mRNA expression was associated with the worst prognosis for progression-free survival in patients with serous ovarian cancer. The dual roles of SK2 mean that SK2 activators could be used as an adjuvant chemotherapy to potentiate treatment efficacy and SK2 inhibitors could be administrated as monotherapy to limit cancer cell dissemination.

Pilot Feasibility Study: 18 F-DPA-714 PET/CT Macrophage Imaging in Triple-Negative Breast Cancers (EITHICS).

ABSTRACT: Tumor-associated macrophages are targets of interest in triple-negative breast cancer (TNBC). The translocator protein 18 kDa (TSPO) is a sensitive marker for macrophages and holds potential relevance in TNBC stratification. This pilot prospective study (EITHICS, NCT04320030) aimed to assess the potential of TSPO PET/CT imaging using 18 F-DPA-714 in primary TNBC, compared with immunohistochemistry, autoradiography, and TSPO polymorphism. PATIENTS AND METHODS: Thirteen TNBC patients were included. They underwent TSPO genotyping (HAB, MAB, LAB), 18 F-FDG PET/CT, and breast MRI. Semiquantitative PET parameters were computed. VOIs were defined on the tumor lesion, healthy breast tissue, and pectoral muscle to obtain SUV, tumor-to-background ratio (TBR), and time-activity curves (TACs). Additionally, immunohistochemistry, 3 H-DPA-714, and 3 H-PK-11195 autoradiography were conducted. RESULTS: The majority of TNBC tumors (11/13, 84%) had a preponderance of M2-polarized macrophages with a median proportion of 82% (range, 44%-94%). 18 F-DPA-714 PET/CT clearly identified TNBC tumors with an excellent TBR. Three distinct patterns of 18 F-DPA-714 TACs were identified, categorized as "above muscular," "equal to muscular," and "below muscular" with reference to the muscular background. For the "above muscular" group (2 HAB and 2 MAB), "equal muscular" group (3 HAB, 3 MAB, and 1 LAB), and "below muscular" group (1 LAB and 1 MAB), tumor TACs showed a 18 F-DPA-714 accumulation slope of 1.35, 0.62, and 0.22, respectively, and a median SUV mean of 4.02 (2.09-5.31), 1.66 (0.93-3.07), and 0.61 (0.43-1.02). CONCLUSIONS: This study successfully demonstrated TNBC tumor targeting by 18 F-DPA-714 with an excellent TBR, allowing to stratify 3 patterns of uptake potentially influenced by the TSPO polymorphism status. Further studies in larger populations should be performed to evaluate the prognostic value of this new biomarker.

First external validity study of the Fagotti score in ovarian cancer.

Epithelial ovarian cancer is mostly discovered at the stage of peritoneal carcinosis. Complete cytoreductive surgery improves overall survival. The Fagotti score is a predictive score of resectability based on peritoneal laparoscopic exploratory. Our aim was to study the inter-observer concordance in an external validation of the Fagotti score. An observational, prospective, multicenter study was conducted using the Francogyn research network. The primary outcome was inter-observer concordance of the Fagotti score. 15 patients in which an ovarian mass was discovered were included. For each patient, the first exploratory laparoscopy before any treatment/chemotherapy was recorded. This bank of 15 videos was subject to blind review accompanied by a Fagotti score rating by 11 gynecological surgeons specializing in oncology. A total of 165 blind reviews were performed. Inter-observer concordance was very good for the Fagotti score with an intraclass correlation coefficient (ICC) of 0.83 [95% CI 0.71; 0.93]. Inter-observer concordance for the adjusted Fagotti score, which accounts for unexplorable areas with extensive carcinomatosis, resulted in an ICC of 0.64 [95% CI 0.46; 0.82]. According to the reviewers, the three least explorable parameters were mesentery involvement, stomach infiltration and liver damage. The ICC of the explorable Fagotti score, i.e. score with deletion of the parameters most often unexplored by laparoscopy, was 0.86 [0.75-0.94]. This study confirms the reproducibility of the Fagotti score during first assessment laparoscopies in cases of advanced ovarian cancer. The explorable Fagotti score has an equivalent or better inter-observer concordance than the Fagotti score.