Cardiac tamponade during pembrolizumab treatment in a patient with ovarian cancer: a case report.

We present the case of a 39-year-old woman with platinum-resistant ovarian cancer who was treated with pembrolizumab. After five cycles of pembrolizumab treatment, she suddenly developed cardiac tamponade with a pleural effusion. The malignant pericardial and pleural effusion had increased, while the other malignant lesions had diminished in size. After pericardial and pleural drainage, no re-accumulation occurred. Pembrolizumab was continued and the patient did not have tumor progression for > 20 months. In some patients with pembrolizumab-induced cardiac tamponade, continuation of pembrolizumab treatment may be possible if other lesions decrease in size and the pericardial effusion can be controlled after drainage.

SNP55, a new functional polymorphism of MDM2-P2 promoter, contributes to allele-specific expression of MDM2 in endometrial cancers.

BACKGROUND: The functional single nucleotide polymorphism (SNP) in the MDM2 promoter region, SNP309, is known to be associated with various diseases, particularly cancer. Although many studies have been performed to demonstrate the mechanism of allele-specific expression (ASE) on SNP309, they have only utilized in vitro techniques. It is unknown whether ASE of MDM2 is ascribed solely to SNP309, in vivo. METHODS: We attempted to evaluate ASE of MDM2 in vivo using post-labeling followed by automated capillary electrophoresis under single-strand conformation polymorphism conditions. For measuring a quantitative difference, we utilized the SNPs on the exons of MDM2 as markers, the status of which was heterozygous in a large population. To address the cause of ASE beyond 20%, we confirmed sequences of both MDM2-3'UTR and promoter regions. We assessed the SNP which might be the cause of ASE using biomolecular interaction analysis and luciferase assay. RESULTS: ASE beyond 20% was detected in endometrial cancers, but not in cancer-free endometria samples only when an SNP rs1690916 was used as a marker. We suspected that this ASE in endometrial cancer was caused by the sequence heterogeneity in the MDM2-P2 promoter, and found a new functional polymorphism, which we labelled SNP55. There was no difference between cancer-free endometria and endometrial cancer samples neither for SNP55 genotype frequencies nor allele frequencies, and so, SNP55 alone does not affect endometrial cancer risk. The SNP55 status affected the DNA binding affinity of transcription factor Sp1 and nuclear factor kappa-B (NFκB). Transcriptional activity of the P2 promoter containing SNP55C was suppressed by NFκB p50 homodimers, but that of SNP55T was not. Only ASE-positive endometrial cancer samples displayed nuclear localization of NFκB p50. CONCLUSIONS: Our findings suggest that both the SNP55 status and the NFκB p50 activity are important in the transcriptional regulation of MDM2 in endometrial cancers.

Association of MDM2 SNP309 and TP53 Arg72Pro polymorphisms with risk of endometrial cancer.

The incidence of endometrial cancer, a common gynecological malignancy, is increasing in Japan. We have previously shown that the ER/MDM2/p53/p21 pathway plays an important role in endometrial carcinogenesis. In the present study, we investigated the effects of germline single nucleotide polymorphisms in murine double minute 2 (MDM2) SNP309, TP53 Arg72Pro, ESR1 PvuII and XbaI, and p21 codon 31 on endometrial cancer risk. We evaluated these polymorphisms in DNA samples from 125 endometrial cancer cases and 200 controls using polymerase chain reaction-based restriction fragment length polymorphism. The association of each genetic polymorphism with endometrial cancer was examined by the odds ratio and 95% confidence interval, which were obtained using logistic regression analysis. The SNP309 GG genotype non-significantly increased the risk of endometrial cancer. The 95% confidence interval for the GG genotype vs. the TT genotype of MDM2 SNP309 was 1.76 (0.93-3.30). Endometrial cancer was not associated with tested SNP genotypes for TP53, ESR1 and p21. The combination of SNP309 GG + TG and TP53 codon 72 Arg/Arg significantly increased endometrial cancer risk. The adjusted OR was 2.53 (95% confidence interval, 1.03-6.21) and P for the interaction was 0.04. This result was supported by in vitro data showing that endometrial cancer cell lines with the SNP309 G allele failed to show growth inhibition by treatment with RITA, which reduces p53-MDM2 binding. The presence of the SNP309 G allele and TP53 codon 72 Arg/Arg genotype is associated with an increased risk of endometrial cancer in Japanese women.

A novel anti-human HB-EGF monoclonal antibody with multiple antitumor mechanisms against ovarian cancer cells.

PURPOSE: Heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) is a member of the EGF family and plays a pivotal role in tumor progression in ovarian cancer. We developed an anti-HB-EGF monoclonal antibody (mAb) and investigated its antitumor activities in vitro and in vivo to evaluate its potential as a therapeutic antibody against ovarian cancer. EXPERIMENTAL DESIGN: We prepared mAbs from HB-EGF null mice immunized with recombinant human soluble HB-EGF and evaluated their binding and neutralizing activity against HB-EGF. Next, we generated a mouse-human chimeric antibody and examined its in vitro and in vivo antitumor activities. RESULTS: Two murine anti-HB-EGF mAbs were developed, and one of them, KM3566, was revealed to have a high binding reactivity for membrane-anchored HB-EGF (pro-HB-EGF) expressed on the cell surface, as well as neutralizing activity against growth promoting activity of soluble HB-EGF. The mouse-human chimeric counterpart for KM3566 (cKM3566) induced dose-dependent antibody-dependent cellular cytotoxicity (ADCC) against cancer cells expressing HB-EGF in vitro, and significantly inhibited tumor growth in severe combined immunodeficient mice inoculated with MCAS or ES-2 human ovarian cancer cells. CONCLUSIONS: A novel anti-HB-EGF chimeric antibody, cKM3566, with two antitumor mechanisms, neutralization and ADCC, exhibits potent in vivo antitumor activity. These results indicate that cKM3566 is a promising antiovarian cancer therapeutic antibody.

Sodium butyrate inhibits the self-renewal capacity of endometrial tumor side-population cells by inducing a DNA damage response.

We previously isolated side-population (SP) cells from a human endometrial cancer cell line, Hec1, and determined that Hec1-SP cells have cancer stem-like cell features. In this study, we isolated SP cells and non-SP (NSP) cells derived from a rat endometrial cell line expressing human [(12)Val] KRAS (RK12V cells) and determined the SP phenotype. RK12V-SP cells showed self-renewal capacity, the potential to develop into stromal cells, reduced expression levels of differentiation markers, long-term proliferating capacity in cultures, and enhanced tumorigenicity, indicating that RK12V-SP cells have cancer stem-like cell features. RK12V-SP cells also display higher resistance to conventional chemotherapeutic drugs. In contrast, treatment with a histone deacetylases (HDAC) inhibitor, sodium butyrate (NaB), reduced self-renewal capacity and completely suppressed colony formation of RK12V-SP cells in a soft agar. The levels of intracellular reactive oxygen species (ROS) and the number of γH2AX foci were increased by NaB treatment of both RK12V-SP cells and RK12V-NSP cells. The expression levels of γH2AX, p21, p27, and phospho-p38 mitogen-activated protein kinase were enhanced in RK12V-SP cells compared with RK12V-NSP cells. These results imply that treatment with NaB induced production of intracellular ROS and DNA damage in both RK12V-SP and RK12V-NSP cells. Following NaB treatment, DNA damage response signals were enhanced more in RK12V-SP cells than in RK12V-NSP cells. This is the first article on an inhibitory effect of NaB on proliferation of endometrial cancer stem-like cells. HDAC inhibitors may represent an attractive antitumor therapy based upon their inhibitory effects on cancer stem-like cells.

Low-dose mithramycin exerts its anticancer effect via the p53 signaling pathway and synergizes with nutlin-3 in gynecologic cancers.

MDM2 is a direct negative regulator of p53. The p53-independent mdm2-P1 and p53-dependent mdm2-P2 promoters have been recently shown to harbor Sp1 binding sites. Mithramycin, an inhibitor of Sp1 DNA binding, has been used clinically to treat hypercalcemia and some types of neoplastic disorders. In this study, we investigated the mechanisms behind the anticancer effect of mithramycin. In gynecologic cancer cells expressing wild-type p53, mithramycin stabilized p53 and increased the expression of the p53 downstream target genes PUMA and p21, arrested the cell cycle, and induced apoptosis. This activation of the p53 signaling pathway was a specific effect of MTH at concentrations <50 nm. Mithramycin temporally decreased transcription of both the mdm2-P1 and -P2 promoters. This was followed by a subsequent increase of mdm2-P2 promoter activity by activated p53. Up-regulated MDM2 was in its active form, and consequently attenuated p53 activity. Although mithramycin activated p53 and suppressed the growth of human gynecologic cancer cell xenografts in mice, this was accompanied with a secondary up-regulation of MDM2. Combined treatment with mithramycin and nutlin-3, a drug that inhibits MDM2-p53 interaction, overcame a secondary up-regulation of MDM2 and synergistically inhibited cancer cell growth by inducing apoptosis through activation of the p53 signaling pathway. These observations provide a better understanding of the mechanisms of mithramycin activity, and suggest a potential role for combining mithramycin and nutlin-3 as a chemotherapeutic treatment for gynecologic cancers.

Endometrial cancer side-population cells show prominent migration and have a potential to differentiate into the mesenchymal cell lineage.

Cancer stem-like cell subpopulations, referred to as "side-population" (SP) cells, have been identified in several tumors based on their ability to efflux the fluorescent dye Hoechst 33342. Although SP cells have been identified in the normal human endometrium and endometrial cancer, little is known about their characteristics. In this study, we isolated and characterized the SP cells in human endometrial cancer cells and in rat endometrial cells expressing oncogenic human K-Ras protein. These SP cells showed i) reduction in the expression levels of differentiation markers; ii) long-term proliferative capacity of the cell cultures; iii) self-renewal capacity in vitro; iv) enhancement of migration, lamellipodia, and uropodia formation; and v) enhanced tumorigenicity. In nude mice, SP cells formed large, invasive tumors, which were composed of both tumor cells and stromal-like cells with enriched extracellular matrix. The expression levels of vimentin, alpha-smooth muscle actin, and collagen III were enhanced in SP tumors compared with the levels in non-SP tumors. In addition, analysis of microdissected samples and fluorescence in situ hybridization of Hec1-SP-tumors showed that the stromal-like cells with enriched extracellular matrix contained human DNA, confirming that the stromal-like cells were derived from the inoculated cells. Moreober, in a Matrigel assay, SP cells differentiated into alpha-smooth muscle actin-expressing cells. These findings demonstrate that SP cells have cancer stem-like cell features, including the potential to differentiate into the mesenchymal cell lineage.

[The etiology of gynecologic cancer].

The incidence of endometrial cancer and ovarian cancer has increased in Japan, during the last decade. On the other hand, the incidence of cervical cancer has declined until the middle of the 1990's. However, in recent years it has been increasing slightly. Change of Japanese women's lifestyle may contribute to the increase in gynecologic cancer incidence in Japan. Infection with high-risk oncogenic human papilloma viruses (HPV) play an important role in cervical carcinogenesis. Advances in understanding of the role of HPV in the etiology of cervical cancer have led to the development, evaluation and recommendation of HPV vaccines. Recently environmental factor and genetic factor related carcinogenesis and development have been investigated of gynecologic cancer. This review provides a summary of these studies about the etiology, the treatment and prevention against gynecologic cancer.

Estrogen deficiency accelerates murine autoimmune arthritis associated with receptor activator of nuclear factor-kappa B ligand-mediated osteoclastogenesis.

The aims of this study were to evaluate the in vivo effects of estrogen deficiency in MRL/lpr mice as a model for rheumatoid arthritis and to analyze the possible relationship between immune dysregulation and receptor activator of nuclear factor-kappaB ligand (RANKL)-mediated osteoclastogenesis. Experimental studies were performed in ovariectomized (Ovx)-MRL/lpr, Ovx-MRL+/+, sham-operated-MRL/lpr, and sham-operated-MRL+/+ mice. Severe autoimmune arthritis developed in younger Ovx-MRL/lpr mice until 24 wk of age, whereas these lesions were entirely recovered by pharmacological levels of estrogen administration. A significant elevation in serum rheumatoid factor, anti-double-stranded DNA, and anti-type II collagen was found in Ovx-MRL/lpr mice and recovered in mice that underwent estrogen administration. A high proportion of CD4(+) T cells bearing RANKL was found, and an enhanced expression of RANKL mRNA and an impaired osteoprotegerin mRNA was detected in the synovium. An increase in both osteoclast formation and bone resorption pits was found. These results indicate that estrogen deficiency may play a crucial role in acceleration of autoimmune arthritis associated with RANKL-mediated osteoclastogenesis in a murine model for rheumatoid arthritis.