The interplay between tumor microenvironment and cancer that causes chemoresistance remains unclear. By analyzing public available microarray datasets, we identified that periostin (POSTN) was overexpressed in cancer stroma in epithelial ovarian cancer (EOC) patients. Immunohistochemistry analysis showed overexpression of stromal POSTN is a powerful independent poor prognostic predictor for EOC patients. Furthermore, patients with high levels of stromal POSTN tend to have higher percentage of cisplatin resistance compared to those with low levels of stromal POSTN. Moreover, we found POSTN treatment can induce cisplatin resistant and activate AKT pathway in A2780 cells in vitro. Inhibition of AKT activity by AKT inhibitor MK-2206 abolished POSTN-induced AKT activation and cisplatin resistance in vitro. Taken together, we found high POSTN expression in cancer microenvironment is correlated with poor prognosis in EOC patients and associated with platinum resistance. The effect of POSTN in cancer stroma cells may activate AKT pathway in tumor and AKT inhibitor can be beneficial to augment the efficacy of existing cancer therapeutics.

There is an urgent need for innovative therapies against ovarian cancer, one of the leading causes of death from gynecological cancers in the United States. Immunotherapy employing Toll-like receptor (TLR) ligands, such as CpG oligodeoxynucleotides (CpG-ODN), may serve as a potentially promising approach in the control of ovarian tumors. The CpG-ODN requires intracellular delivery into the endosomal compartment, where it can bind to TLR9 in order to activate the immune system. In the current study, we aim to investigate whether the antimicrobial polypeptide from the cathelicidin family, LL-37, could enhance the immunostimulatory effects of CpG-ODN by increasing the uptake of CpG-ODN into the immune cells, thus enhancing the antitumor effects against ovarian cancer. We found that treatment with the combination of CpG-ODN and LL-37 generated significantly better therapeutic antitumor effects and enhanced survival in murine ovarian tumor-bearing mice compared with treatment with CpG-ODN or LL-37 alone. We also observed that treatment with the combination of CpG-ODN and LL-37 enhanced proliferation and activation of natural killer (NK) cells, but not CD4(+) or CD8(+) T cells, in the peritoneal cavity. Furthermore, in vivo antibody depletion experiments indicated that peritoneal NK cells played a critical role in the observed antitumor effects. Thus, our data suggest that the combination of CpG-ODN with LL-37 peptide may lead to the control of ovarian tumors through the activation of innate immunity.

Endometrial stromal tumors are rare uterine tumors (<1%). Four main categories include endometrial stromal nodule, low-grade endometrial stromal sarcoma (LG-ESS), high-grade endometrial stromal sarcoma (HG-ESS), and uterine undifferentiated sarcoma (UUS). This review is a series of articles discussing the uterine sarcomas. LG-ESS, a hormone-dependent tumor harboring chromosomal rearrangement, is an indolent tumor with a favorable prognosis, but characterized by late recurrences even in patients with Stage I disease, suggesting the requirement of a long-term follow-up. Patients with HG-ESS, based on the identification of YWHAE-NUTM2A/B (YWHAE-FAM22A/B) gene fusion, typically present with advanced stage diseases and frequently have recurrences, usually within a few years after initial surgery. UUS is, a high-grade sarcoma, extremely rare, lacking a specific line of differentiation, which is a diagnosis of exclusion (the wastebasket category, which fails to fulfill the morphological and immunohistochemical criteria of translocation-positive ESS). Surgery is the main strategy in the management of uterine sarcoma. Due to rarity, complex biological characteristics, and unknown etiology and risk factors of uterine sarcomas, the role of adjuvant therapy is not clear. Only LG-ESS might respond to progestins or aromatase inhibitors.

Uterine sarcomas account for 3-7% of all uterine cancers. Because of their rarity, unknown etiology, and highly divergent genetic aberration, there is a lack of consensus on risk factors for occurrence and predictive poor outcomes as well as optimal therapeutic choices. Tumor types according to the World Health Organization classification include leiomyosarcoma, endometrial stroma sarcoma, and undifferentiated sarcoma. Staging is done using the 2014 Federation International Gynecology and Obstetrics and 2010 American Joint Committee on Cancer tumor, lymph node, and metastases systems. Tumor grade can be classified based on the French Federation of Cancer Centers Sarcoma Group system or the Broder's system that incorporates tumor differentiation, mitotic count, and tumor necrosis. This review is a series of articles discussing uterine sarcoma, and this is Part I, which focuses on one of the subtypes of uterine sarcomas-uterine leiomyosarcoma. The clinical characteristics, diagnosis, outcome, and recent advances are summarized in this article.

Amplification and overexpression of the MYC oncogene in tumor cells, including ovarian cancer cells, correlates with poor responses to chemotherapy. As MYC is not directly targetable, we have analyzed molecular pathways downstream of MYC to identify potential therapeutic targets. Here we report that ovarian cancer cells overexpressing glutaminase (GLS), a target of MYC and a key enzyme in glutaminolysis, are intrinsically resistant to platinum-based chemotherapy and are enriched with intracellular antioxidant glutathione. Deprivation of glutamine by glutamine-withdrawal, GLS knockdown, or exposure to the GLS inhibitor CB-839 resulted in robust induction of reactive oxygen species in high GLS-expressing but not in low GLS-expressing ovarian cancer cells. Treatment with CB-839 rendered GLShigh cells vulnerable to the poly(ADP-ribose) polymerase (PARP) inhibitor, olaparib, and prolonged survival in tumor-bearing mice. These findings suggest consideration of applying a combined therapy of GLS inhibitor and PARP inhibitor to treat chemoresistant ovarian cancers, especially those with high GLS expression. Significance: Targeting glutaminase disturbs redox homeostasis and nucleotide synthesis and causes replication stress in cancer cells, representing an exploitable vulnerability for the development of effective therapeutics.

Background: It is important to develop innovative therapies for advanced stage cancers in addition to the conventional therapies including chemotherapy, radiation and surgery. Antigenspecific immunotherapy has emerged as a novel alternate therapy for advanced stage cancers, which may be employed in conjunction with conventional therapies.

Therapeutic human papillomavirus (HPV) vaccines targeting E6 and/or E7 antigens represent an opportunity to control HPV-associated lesions. We have previously generated several therapeutic DNA vaccines targeting HPV-16 E7 antigen and generated significant antitumor effects. Since regulatory T cells (Tregs) play an important role in suppressing immune responses against tumors by immunotherapy, such as DNA vaccines, we tested if the therapeutic effects of a DNA vaccine encoding E7 linked to heat shock protein 70 (Hsp70) can be improved by a strategy to deplete Tregs using a anti-CD25 monoclonal antibody (PC61) in vaccinated mice. We found that administration of PC61 prior to vaccination with E7/Hsp70 DNA was capable of generating higher levels of E7-specific CD8+ T cells compared to the control antibody, leading to significantly improved therapeutic and long-term protective antitumor effects against an E7-expressing tumor, TC-1. Thus, a strategy to deplete CD4+CD25+ Tregs in conjunction with therapeutic tumor antigen-specific DNA vaccine may represent a potentially promising approach to control tumor. The clinical implications of our study are discussed.

Primary fallopian tube carcinoma (PFTC) is a rare gynecological malignancy with the following characteristics: its preoperative diagnosis is easy to miss or delay because of a lack of specific symptoms and signs; it is difficult to distinguish from serous epithelial ovarian cancer or primary peritoneal serous carcinoma during or even after operation because they have the same histopathological features; and there is uncertainty regarding the optimal management because of the lack of available standard guidelines. All of these factors contribute to the major challenge of undertaking a comprehensive study of this disease. To improve our understanding of this rare disease, the domestic data were summarized first. We searched PubMed on this topic, using the term "primary fallopian tube tumor and Taiwan" (from January 1, 1990 to November 3, 2013) and identified 15 published articles, but only 11 studies focused on the outcome of patients with PFTC in Taiwan. These limited data were not enough to increase our knowledge in dealing with this disease; therefore, the addition of large series or published review articles addressing this topic was needed. According to these reports, we concluded: (1) the main type of PFTC was serous type, often poorly differentiated; (2) the diagnosis of PFTC is frequently missed or delayed; (3) PFTC is often of an earlier International Federation of Gynecology and Obstetrics (FIGO) stage than is epithelial ovarian cancer (EOC), because of the appearance of earlier but nonspecific symptoms or signs, such as abdominal pain, vaginal bleeding, and watery discharge or mass; (4) the most important clinicopathological prognostic factor was FIGO stage; (5) the therapeutic strategy is still uncertain, but is often based on the guidelines for treating EOC. An intensive surgical effort such as a complete surgical resection or optimal cytoreduction surgery with a minimal residual tumor followed by a platinum-paclitaxel combination chemotherapy with/without targeted therapy (for example, antiangiogenesis agents) may provide the best possibility of disease-free or overall survival.