A Tumor Mitochondria Vaccine Protects against Experimental Renal Cell Carcinoma

Mitochondria provide energy for cells via oxidative phosphorylation. Reactive oxygen species, a byproduct of this mitochondrial respiration, can damage mitochondrial DNA (mtDNA), and somatic mtDNA mutations have been found in all colorectal, ovarian, breast, urinary bladder, kidney, lung, and pancreatic tumors studied. The resulting altered mitochondrial proteins or tumor-associated mitochondrial Ags (TAMAs) are potentially immunogenic, suggesting that they may be targetable Ags for cancer immunotherapy. In this article, we show that the RENCA tumor cell line harbors TAMAs that can drive an antitumor immune response. We generated a cellular tumor vaccine by pulsing dendritic cells with enriched mitochondrial proteins from RENCA cells. Our dendritic cell-based RENCA mitochondrial lysate vaccine elicited a cytotoxic T cell response in vivo and conferred durable protection against challenge with RENCA cells when used in a prophylactic or therapeutic setting. By sequencing mtDNA from RENCA cells, we identified two mutated molecules: COX1 and ND5. Peptide vaccines generated from mitochondrial-encoded COX1 but not from ND5 had therapeutic properties similar to RENCA mitochondrial protein preparation. Thus, TAMAs can elicit effective antitumor immune responses, potentially providing a new immunotherapeutic strategy to treat cancer

From the endometrium physiology to a comprehensive strategy for the discovery of ovarian cancer biomarkers

The development of comprehensive strategies for biomarker discovery of gynecological cancers is needed. The unique physiology of the female genital track revolves around ovulatory cycles ending by the proteolysis of the endometrium triggered by progesterone decline during the last part of the luteal phase. Building on the known link between incessant ovulation and ovarian cancer, we hypothesize that life-long menstruations could damage neighboring organs such as fallopian tubes, ovaries and peritoneum via endometrial secretions, and thus endometrium neighboring structures may have developed highly efficient protective strategies that could, in turn, be hijacked by cancer cells for survival and invasion. After literature review, we could classify the molecules involved in ovulation and menstruation pathways in three main categories: proteases, proteases inhibitors and cell-surface protectors. Strikingly, all validated biomarkers for ovarian cancers belong to at least one of these categories. We thus propose the development of comprehensive methods for identification of early diagnostic markers for gynecological cancers using systematical mapping and characterization of surface or soluble molecules belonging to physiological pathways linked to menstruation and differently expressed during luteal cycles

Advances in Immunotherapy in the Treatment of Ovarian Cancer

Objectives To get familiar with the different types of immunotherapy Discuss the limitations of checkpoint blocade in the treatment of ovarian cancer Understand the differences between CAR T cells and TCR T cells Introduce the concept of mutanome based individualized innumotherap

Convergence of Multiple Signaling Cascades at Glycogen Synthase Kinase 3: Edg Receptor-Mediated Phosphorylation and Inactivation by Lysophosphatidic Acid through a Protein Kinase C-Dependent Intracellular Pathway

Lysophosphatidic acid (LPA) is a natural phospholipid with multiple biological functions. We show here that LPA induces phosphorylation and inactivation of glycogen synthase kinase 3 (GSK-3), a multifunctional serine/threonine kinase. The effect of LPA can be reconstituted by expression of Edg-4 or Edg-7 in cells lacking LPA responses. Compared to insulin, LPA stimulates only modest phosphatidylinositol 3-kinase (PI3K)-dependent activation of protein kinase B (PKB/Akt) that does not correlate with the magnitude of GSK-3 phosphorylation induced by LPA. PI3K inhibitors block insulin- but not LPA-induced GSK-3 phosphorylation. In contrast, the effect of LPA, but not that of insulin or platelet-derived growth factor (PDGF), is sensitive to protein kinase C (PKC) inhibitors. Downregulation of endogenous PKC activity selectively reduces LPA-mediated GSK-3 phosphorylation. Furthermore, several PKC isotypes phosphorylate GSK-3 in vitro and in vivo. To confirm a specific role for PKC in regulation of GSK-3, we further studied signaling properties of PDGF receptor β subunit (PDGFRβ) in HEK293 cells lacking endogenous PDGF receptors. In clones expressing a PDGFRβ mutant wherein the residues that couple to PI3K and other signaling functions are mutated with the link to phospholipase Cγ (PLCγ) left intact, PDGF is fully capable of stimulating GSK-3 phosphorylation. The process is sensitive to PKC inhibitors in contrast to the response through the wild-type PDGFRβ. Therefore, growth factors, such as PDGF, which control GSK-3 mainly through the PI3K-PKB/Akt module, possess the ability to regulate GSK-3 through an alternative, redundant PLCγ-PKC pathway. LPA and potentially other natural ligands primarily utilize a PKC-dependent pathway to modulate GSK-3

Preoperative predictors that impact the survival and outcome of patients undergoing secondary cytoreduction for ovarian cancer

<p>This study aimed to examine the factors affecting feasibility of optimal and complete secondary cytoreductive surgery (SCRS) and to characterise the prognostic factors that correlate with improved survival in patients who underwent SCRS. This is a retrospective single-institutional cohort study of patients who underwent SCRS for recurrent epithelial ovarian cancer (EOC). One hundred and forty-eight patients met inclusion criteria. Platinum sensitivity was associated with complete cytoreduction at SCRS. Factors associated with suboptimal cytoreduction (SOC) were age >55 years, serous histology, largest tumour implant size >4 cm, and SOC at primary surgery. Overall survival analysis showed significantly longer survival with complete cytoreduction compared to optimal and SOC. Surgical outcome of SCRS was an independent predictor of survival regardless of the outcome of primary cytoreduction. Location of the largest implant, DFI and timing of chemotherapy also impact on survival.</p

Ovarian granulosa cell tumor characterization identifies FOXL2 as an immunotherapeutic target

Granulosa cell tumors (GCT) are rare ovarian malignancies. Due to the lack of effective treatment in late relapse, there is a clear unmet need for novel therapies. Forkhead Box L2 (FOXL2) is a protein mainly expressed in granulosa cells (GC) and therefore is a rational therapeutic target. Since we identified tumor infiltrating lymphocytes (TILs) as the main immune population within GCT, TILs from 11 GCT patients were expanded, and their phenotypes were interrogated to determine that T cells acquired late antigen-experienced phenotypes and lower levels of PD1 expression. Importantly, TILs maintained their functionality after ex vivo expansion as they vigorously reacted against autologous tumors (100% of patients) and against FOXL2 peptides (57.1% of patients). To validate the relevance of FOXL2 as a target for immune therapy, we developed a plasmid DNA vaccine (FoxL2–tetanus toxin; FoxL2-TT) by fusing Foxl2 cDNA with the immune-enhancing domain of TT. Mice immunization with FoxL2-TT controlled growth of FOXL2-expressing ovarian (BR5) and breast (4T1) cancers in a T cell–mediated manner. Combination of anti–PD-L1 with FoxL2-TT vaccination further reduced tumor progression and improved mouse survival without affecting the female reproductive system and pregnancy. Together, our results suggest that FOXL2 immune targeting can produce substantial long-term clinical benefits. Our study can serve as a foundation for trials testing immunotherapeutic approaches in patients with ovarian GCT