The role of myeloid-derived suppressor cells in endometrial cancer displaying systemic inflammatory response: clinical and preclinical investigations

Systemic inflammatory responses including thrombocytosis, leukocytosis, or neutrophilia have gained attention as prognostic indicators in patients with various solid malignancies.current study, we aimed to investigate the clinical implications and underlying biological mechanism of the systemic inflammatory response in endometrial cancer. Clinical data from 900 patients with endometrial cancer were analyzed to investigate the association between pretreatment leukocytosis, thrombocytosis, and treatment outcome. Clinical samples, endometrial cancer cell lines, and a mouse model of endometrial cancer were used to examine the mechanisms responsible for systemic inflammatory response in endometrial cancer, focusing on the role of tumor-derived granulocyte colony-stimulating factor (G-CSF) and MDSCs. Then, we showed that pretreatment concurrent leukocytosis and thrombocytosis is associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. In vitro and in vivo experiments revealed that tumor-derived G-CSF and G-CSF-mediated IL-6 production from the tumor microenvironment are involved in the development of leukocytosis and thrombocytosis in patients with endometrial cancer. Moreover, increased tumor-infiltrating MDSCs induced by tumor-derived G-CSF, MDSC-mediated T cell suppression, and MDSC-mediated cancer stem cell induction are responsible for progression and chemoresistance in this type of endometrial cancer. MDSC depletion using an anti-Gr-1 neutralizing antibody or inhibition of MDSC activity by celecoxib inhibited tumor growth and enhanced chemosensitivity in endometrial cancer displaying concurrent leukocytosis and thrombocytosis. In conclusion, Pretreatment concurrent leukocytosis and thrombocytosis are associated with significantly shorter survival and decreased chemosensitivity among patients with endometrial cancer. Combining MDSC-targeting treatments with current standard chemotherapies might have therapeutic efficacy for these patients.

Synthesis and Glycan-Protein Interaction Studies of Se-Sialosides by 77Se NMR

To expand the potential of Se-carbohydrates for multifunctional mimicry of sugars, herein we addressed the synthesis of the highly challenging and biologically significant Se-glycosides of sialic acid (Se-sialosides). An α-sialyl selenolate anion generated in situ smoothly reacted with electrophiles to give α-Se-sialosides as single stereoisomers. A Se-sialoside was sequentially incorporated with selenium, producing a triseleno-sialoside. This molecule was used as a ⁷⁷Se NMR-active handle for studying glycan-protein interaction, revealing different binding profiles of sialic acid binding proteins.

Pre-treatment prognostic nutritional index is superior to platelet count in predicting disease-specific survival in patients with epithelial ovarian cancer

OBJECTIVE

Both pre-treatment prognostic nutritional index and platelet count were reported to be independent prognostic factors in epithelial ovarian cancer patients. However, their relationship has not been investigated. The aim of this study was to investigate the association between the pre-treatment prognostic nutritional index and platelet count, and to compare their utility as prognostic indicators for patients with epithelial ovarian cancer.

METHODS

Clinical data from epithelial ovarian cancer patients treated between April 2007 and March 2016 were collected and retrospectively reviewed. The association between the pre-treatment prognostic nutritional index and platelet count was evaluated using Spearman's rank correlation coefficient. After determining the cut-off values for the pre-treatment platelet count and prognostic nutritional index for predicting disease-specific survival by time-dependent receiver operating characteristic (ROC) curve analysis, we compared the clinical utility of platelet counts and the prognostic nutritional index.

RESULTS

A total of 308 patients were included in the analysis. Median age was 57 (range 16-81) years. The International Federation of Gynecology and Obstetrics (FIGO) clinical stage at initial diagnosis was stage I in 137 patients (44.5%), stage II in 27 patients (8.8%), stage III in 96 patients (31.2%), and stage IV in 48 patients (15.6%). Most patients (37.7%) had serous adenocarcinoma. Of the 295 patients who underwent primary or interval debulking surgery, optimal debulking was performed in 240 patients (77.9%). Decresed pre-treatment prognostic nutritional index was correlated with increased pre-treatment platelet count (p<0.0001), and when compared, the prognostic nutritional index had a significantly greater area under the ROC curve value than the platelet count for predicting disease-specific survival (0.8348 vs 0.6413, p=0.0007). An elevated platelet count was significantly associated with a shorter disease-specific survival in epithelial ovarian cancer patients (p<0.0001). However, when the prognostic nutritional index was adjusted, an elevated platelet count did not provide any prognostic information (lower prognostic nutritional index, p=0.45; higher prognostic nutritional index, p=0.77).

CONCLUSIONS

The pre-treatment prognostic nutritional index was superior to the platelet count for predicting disease-specific survival for epithelial ovarian cancer patients. Although pre-treatment thrombocytosis was reported to be an independent poor prognostic factor in epithelial ovarian cancer patients, it generally reflects a lower prognostic nutritional index, and did not provide any prognostic information when the prognostic nutritional index was adjusted.

Constrained sialic acid donors enable selective synthesis of α-glycosides

Sialic acid is a sugar residue present in many biologically significant glycans of mammals, commonly as a terminal α-glycoside. The chemical structure of sialic acid, which features an anomeric center with carboxyl and methylene substituents, poses a challenge for synthesis of the α-glycoside, thus impeding biological and therapeutic studies on sialic acid–containing glycans. We present a robust method for the selective α-glycosidation of sialic acid using macrobicyclized sialic acid donors as synthetic equivalents of structurally constrained oxocarbenium ions to impart stereoselectivity. We demonstrate the power of our method by showcasing broad substrate scope and applicability in the preparation of diverse sialic acid–containing architectures.

Estrogen stimulates female cancer progression by inducing myeloid-derived suppressive cells: investigations on pregnant and non-pregnant experimental models

Objective

To investigate the clinical implications of 17β-estradiol (E2) in estrogen receptor α (ERα)-negative female cancer progression as well as the underlying biological mechanisms.

Methods

Clinical data from 306 locally-advanced cervical cancer (stage IIB-IVA) patients were analyzed in order to investigate the relationships between age, serum E2 levels, and treatment outcomes. Clinical samples, ERα-negative cervical and breast cancer cell lines, and mouse xenograft models of cervical and breast cancers were employed in order to elucidate the mechanisms responsible for the E2- and pregnancy-mediated progression of cervical and breast cancers, with a focus on the role of myeloid-derived suppressor cells (MDSC).

Results

Younger patients with elevated E2 levels showed significantly shorter progression-free survival (P = 0.040) and overall survival (P = 0.039). The exogenous E2 treatment stimulated the mobilization of MDSC from bone marrow and directly augmented their suppressive activities, leading to the progression of ERα-negative cervical and breast cancers. The co-administration of an anti-Gr-1 neutralizing antibody with E2 prevented the E2-mediated induction of MDSC, and attenuated E2-mediated tumor growth in cervical and breast cancer xenografts. Significantly increased MDSC numbers and enhanced tumor growth were observed during pregnancy in mice with cervical or breast cancer. Significantly increased MDSC numbers were also observed during pregnancy in cervical cancer patients.

Conclusions

E2 facilitates the progression of ERα-negative cervical or breast cancer under non-pregnant and pregnant conditions by inducing MDSC. MDSC inhibition therapy may have therapeutic efficacy in premenopausal or pregnant female cancer patients.

A phase II study of irinotecan combined with S-1 in patients with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy

OBJECTIVES

We conducted a phase II study to investigate the efficacy and toxicities of irinotecan plus oral S-1 in patients with advanced or recurrent uterine cervical cancer.

METHODS

Patients with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy were enrolled. Irinotecan (150 mg/m²) was administered intravenously over the course of 90 min on day 1, and S-1 (80 mg/m²) was given orally in two divided doses from days 1 to 14 of a 21 day cycle. The primary endpoint of this phase II study was response rate. Secondary endpoints included safety, progression free survival, and overall survival.

RESULTS

A total of 19 patients were enrolled and treated. The response rate was 29.4%. Grade 3-4 hematologic toxicities were observed in three patients (15.7%). The only grade 3-4 non-hematologic toxicity observed was grade 3 diarrhea. The median progression free survival and overall survival were 3 months and 9 months, respectively.

CONCLUSION

S-1 plus irinotecan in a 3 weekly setting is safe and active in women with advanced or recurrent cervical cancer previously treated with platinum based chemotherapy. Future corroborative clinical studies are warranted.

Radiotherapy for isolated recurrent epithelial ovarian cancer: A single institutional experience

AIM

To evaluate the efficacy and toxicity of external beam radiotherapy (RT) for isolated recurrent epithelial ovarian cancer (EOC).

METHODS

Twenty-four isolated recurrent EOC patients treated with RT at Osaka University Hospital between January 2000 and January 2017 were included in the current study. Data regarding the primary or recurrent diseases, follow-up findings, and efficacy or toxicities of RT were collected and retrospectively analyzed. Survival rates were calculated using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

Their median age was 59 years. Most patients had International Federation of Gynecology and Obstetrics stage III-IV diseases at the initial diagnosis. Histologically, serous adenocarcinoma was predominant, followed by clear cell adenocarcinoma. All patients had received at least one regimen of platinum-based chemotherapy; 8 were platinum-sensitive relapse and the others were platinum-resistant. Lymph nodes were the most common sites of recurrence, and the median tumor size was 25.5 mm. The median total dose of RT administered was 54 Gy, with a median daily dose of 2 Gy. RT was well-tolerated, and no patients experienced Grade 3/4 toxicities. The in-field overall response rate was 58.3% (14/24), the median regression rate was -40.2% (range: -100 to 0) and the median survival period after RT was 17 months. The 1-year survival and local progression-free survival rates after RT were 66.7% and 45.8%, respectively.

CONCLUSION

RT showed significant antitumor effect against isolated recurrent EOC without causing severe toxicities. Prospective studies with sufficient statistical power are warranted to further evaluate the role of RT in this patient population.

Sialyl LewisX mimic-decorated liposomes for anti-angiogenic everolimus delivery to E-selectin expressing endothelial cells

In this study, we developed novel E-selectin-targeting liposomes, i.e., 3′-(1-carboxy)ethyl sialyl LewisX (3′-CE sLeX) mimic liposomes, for targeted delivery of everolimus (EVE) in anti-angiogenic therapy. We investigated the uptake and efficacy of these E-selectin targeting liposomes in inflammatory cytokine-treated human umbilical vein endothelial cells (HUVECs). The uptake of EVE in 3′-CE sLeX mimic liposomes increased steadily and almost caught up with the uptake of plain EVE at 3 h, which was higher than that in PEGylated liposomes (PEG-liposomes). Inhibition of uptake by anti-E-selectin antibody suggested involvement of E-selectin-mediated endocytotic processes. Migration in cells treated with EVE/3′-CE sLeX mimic liposomes was suppressed by more than half when compared to the control. This treatment was also seen to significantly inhibit the formation of capillary tubes and networks. In addition, Thr389 phosphorylation of pS6 kinase, as a marker of mTOR activity, was remarkably suppressed to less than endogenous levels by EVE/3′-CE sLeX mimic liposomes. In conclusion, the present study demonstrated that EVE/3′-CE sLeX mimic liposomes were intracellularly taken up by E-selectin and prompted anti-angiogenic effects of EVE involved in the mTOR signaling pathway. However, moderate retention of EVE in the liposomes might limit the targeting ability of 3′-CE sLeX mimic liposomes.

Novel E-selectin-targeting liposomes deliver everolimus to E-selectin expressing endothelial cells and accelerate its anti-angiogenic effect.

Myeloid-derived suppressor cells and their role in gynecological malignancies

Myeloid-derived suppressor cells are a heterogeneous population of immature myeloid cells that exhibit immunosuppressive activity (they block the proliferation and activity of both T cells and natural killer cells). In addition to their role in suppressing immune responses, myeloid-derived suppressor cells directly stimulate tumor cell proliferation, metastasis, and angiogenesis. In the area of gynecological cancer, increased numbers of circulating myeloid-derived suppressor cells or tumor-infiltrating myeloid-derived suppressor cells have been detected, and the increased frequencies of myeloid-derived suppressor cells are associated with a poor prognosis. Thus, the successful myeloid-derived suppressor cells depletion may hold the key to maximizing existing anti-cancer therapies and improving the prognosis of gynecological cancer. In this review, we summarize current knowledge regarding myeloid-derived suppressor cells biology, clinical significance of myeloid-derived suppressor cells, and the potential myeloid-derived suppressor cells–targeting strategies in gynecological cancer.

The Highly Metastatic Nature of Uterine Cervical/Endometrial Cancer Displaying Tumor-Related Leukocytosis: Clinical and Preclinical Investigations

Purpose: The aim of this study was to investigate the metastatic potential of uterine cervical and endometrial cancer displaying tumor-related leukocytosis (TRL).Experimental Design: Clinical data on uterine cervical (N = 732) and endometrial cancer (N = 900) were collected, and the metastatic potential of TRL-positive cancer was evaluated in univariate and multivariate analyses. Tumor and blood samples obtained from patients with cervical cancer, cervical cancer cell lines, and a mouse model of cervical cancer were used to examine the mechanisms underlying the highly metastatic nature of TRL-positive cancer, focusing on tumor-derived G-CSF and the myeloid-derived suppressor cell (MDSC)-mediated premetastatic niche.Results: Pretreatment TRL was significantly associated with visceral organ metastasis in patients with uterine cervical or endometrial cancer. The patients with TRL-positive cervical cancer displayed upregulated tumor G-CSF expression, elevated G-CSF levels, and increased MDSC frequencies in the peripheral blood compared with the TRL-negative patients. In vitro and in vivo investigations revealed that MDSCs produced in response to tumor-derived G-CSF are involved in premetastatic niche formation, which promotes visceral organ metastasis of TRL-positive cancer. The depletion of MDSCs attenuated this premetastatic niche formation and effectively inhibited the visceral organ metastasis of TRL-positive cancer.Conclusions: Uterine cervical/endometrial cancer displaying TRL is a distinct clinical entity with high metastatic potential. Tumor-derived G-CSF and the MDSC-mediated premetastatic niche are responsible for the highly metastatic nature of this type of cancer. MDSC-targeting therapy might represent a potential strategy for combating metastasis derived from TRL-positive uterine cancer. Clin Cancer Res; 24(16); 4018-29. ©2018 AACR.

PM01183 inhibits myeloid-derived suppressor cells in vitro and in vivo

AIM

To evaluate the ability of PM01183 to eliminate myeloid-derived suppressor cells (MDSCs).

MATERIALS & METHODS

The effect of PM01183 on MDSCs, NK cells and CD8⁺ T cells was examined in vitro and in vivo. The mechanism by which PM01183 depletes MDSCs was also investigated.

RESULTS

PM01183 reduced the number of MDSCs by inducing apoptosis and attenuated the MDSC-mediated suppression of CD8⁺ T cells by inhibiting arginase-1 production, whereas no significant effect on CD8⁺ T or NK cells was noted. The inhibitory effect of PM01183 on MDSC was mediated by the attenuation of STAT3 phosphorylation. The inhibitory effect of PM01183 on MDSCs was greater than those of existing anticancer agents.

CONCLUSION

PM01183 exhibits strong inhibitory effects on MDSCs.

Comparison of clinical utilities of the platelet count and platelet-lymphocyte ratio for predicting survival in patients with cervical cancer: a single institutional study and literature review

Objective

To compare the clinical utilities of the platelet count and platelet-lymphocyte ratio (PLR) for predicting survival in patients with cervical cancer.

Results

Multivariate analyses demonstrated that thrombocytosis and elevated PLR were found to be independent prognostic factors for progression-free survival (PFS, P = 0.0077, P = 0.044) and overall survival (OS, P = 0.025, P = 0.019) in separate Multivariate analyses. In the ROC analysis, the platelet count showed a significantly greater area under the ROC curve (AUC) value than that of PLR for predicting patient recurrence (0.5941 versus 0.5331, p = 0.018) and survival (0.6139 versus 0.5468, p = 0.029). In patients without thrombocytosis, elevated PLR correlated with shorter survival (PFS, P = 0.041; OS, P = 0.017). In contrast, PLR in patients with thrombocytosis did not provide prognostic information. We divided patients into 3 prognostic groups using platelet counts and PLR: high-risk (thrombocytosis with any PLR); intermediate-risk (elevated PLR without thrombocytosis); low-risk (none of the above), which allowed for individualized and accurate survival estimates.

Materials and Methods

The baseline characteristics and clinical outcomes of cervical cancer patients were identified. Patients were grouped according to their pretreatment platelet counts or PLR, and clinicopathological characteristics and patient survival were then compared between these groups. The clinical utilities of the platelet count and PLR were compared using a time-dependent receiver operating characteristic (ROC) analysis.

Conclusions

Pretreatment thrombocytosis and elevated PLR were identified as independent predictors in cervical cancer patients. Platelet counts were superior to PLR for predicting the prognosis of uterine cervical cancer patients. Our prognostic model consisting of platelet counts and PLR offers individualized survival estimates.

Development of new ganglioside probes and unraveling of raft domain structure by single-molecule imaging

Gangliosides are involved in a variety of biological roles and are a component of lipid rafts found in cell plasma membranes (PMs). Gangliosides are especially abundant in neuronal PMs and are essential to their physiological functions. However, the dynamic behaviors of gangliosides have not been investigated in living cells due to a lack of fluorescent probes that behave like their parental molecules. We have recently developed, using an entirely chemical method, four new ganglioside probes (GM1, GM2, GM3, and GD1b) that act similarly to their parental molecules in terms of raft partitioning and binding affinity. Using single fluorescent-molecule imaging, we have found that ganglioside probes dynamically enter and leave rafts featuring CD59, a GPI-anchored protein. This occurs both before and after stimulation. The residency time of our ganglioside probes in rafts with CD59 oligomers was 48ms, after stimulation. The residency times in CD59 homodimer and monomer rafts were 40ms and 12ms, respectively. In this review, we introduce an entirely chemical-based ganglioside analog synthesis method and describe its application in single-molecule imaging and for the study of the dynamic behavior of gangliosides in cell PMs. Finally, we discuss how raft domains are formed, both before and after receptor engagement. This article is part of a Special Issue entitled Neuro-glycoscience, edited by Kenji Kadomatsu and Hiroshi Kitagawa.

Syntheses of Fluorescent Gangliosides for the Studies of Raft Domains

Gangliosides, glycosphingolipids containing one or more sialic acids in the glycan chain, are involved in various important biological processes in cell plasma membranes (PMs). However, the behaviors and functions of gangliosides are poorly understood, primarily because of the lack of fluorescent analogs that are equivalent to native gangliosides that can be used as chemical and physical probes. In this study, we developed entirely chemical methods to synthesize fluorescent gangliosides (GM3, GM2, GM1, and GD1b) in which the glycan components are site-specifically labeled with various fluorescent dyes. The functional evaluations of the synthesized fluorescent gangliosides demonstrated the great influence of fluorescent dye on the physical properties of gangliosides in PMs and revealed the fluorescent ganglioside analogs which show similar behaviors to the native gangliosides.

Rare Primary Adenocarcinoma of the Broad Ligament: Report of Two Cases and a Literature Review

Malignant primary tumors arising in the uterine broad ligament are extremely rare, and only 26 cases have been reported to date. We describe 2 new cases of primary adenocarcinoma of the broad ligament, and we review the previous literature on such rare tumors. In Case 1, a 71-year-old woman presented with a 2-month history of increased yellow vaginal discharge and lower abdominal pain during bowel movement. Transvaginal sonography revealed a 6.5 cm mass located on the dorsum of the uterus and a 7.0 cm mass (with cystic and solid parts) near the right adnexa. We postoperatively diagnosed the mass as a high-grade serous carcinoma of the broad ligament (pT3cNXM0). The patient is currently receiving adjuvant chemotherapy with paclitaxel and carboplatin. In Case 2, during a complete medical checkup a 43-year-old woman was found to have a pelvic mass indicative of leiomyoma. Transvaginal sonography revealed a 3.8 cm mass located on the dorsum of the uterus. Following surgery, we diagnosed the mass as a clear cell adenocarcinoma of the broad ligament (pT2bN1M0). This patient is also now receiving adjuvant chemotherapy with paclitaxel and carboplatin.