Iori Kisu

Pathological Steps of Cancer-Related Lymphedema: Histological Changes in the Collecting Lymphatic Vessels after Lymphadenectomy

Introduction To date, an electron microscopy study of the collecting lymphatic vessels has not been conducted to examine the early stages of lymphedema. However, such histological studies could be useful for elucidating the mechanism of lymphedema onset. The aim of this study was to clarify the changes occurring in collecting lymphatic vessels after lymphadenectomy. Methods The study was conducted on 114 specimens from 37 patients who developed lymphedema of the lower limbs after receiving surgical treatment for gynecologic cancers and who consulted the University of Tokyo Hospital and affiliated hospitals from April 2009 to March 2011. Lymphatic vessels that were not needed for lymphatico venous anastomosis surgery were trimmed and subsequently examined using electron microscopy and light microscopy. Results Based on macroscopic findings, the histochemical changes in the collecting lymphatic vessels were defined as follows: normal, ectasis, contraction, and sclerosis type (NECST). In the ectasis type, an increase in endolymphatic pressure was accompanied by a flattening of the lymphatic vessel endothelial cells. In the contraction type, smooth muscle cells were transformed into synthetic cells and promoted the growth of collagen fibers. In the sclerosis type, fibrous elements accounted for the majority of the components, the lymphatic vessels lost their transport and concentrating abilities, and the lumen was either narrowed or completely obstructed. Conclusions The increase in pressure inside the collecting lymphatic vessels after lymphadenectomy was accompanied by histological changes that began before the onset of lymphedema.

Uterine autotransplantation in cynomolgus macaques: the first case of pregnancy and delivery

BACKGROUND For women with congenital uterine infertility, or for those who have undergone hysterectomy, uterine transplantation is one of the potential treatments to regain fertility. In this study, we utilized a primate model of uterine transplantation, and evaluated the patency of our microsurgical anastomoses, and the perfusion of the transplanted uterus. METHODS Two female cynomolgus monkeys underwent surgery. We anastomosed two arteries and one vein in Case 1 and two arteries and two veins in Case 2. The arteries used were the uterine arteries and the anastomosis was done to the external iliac artery. We used one of the ovarian veins in both animals, but resected the ovary from the Fallopian tube. Uterine arterial blood flow and uterine size were determined by intraoperative indocyanine green (ICG) angiography and ultrasonography. The biopsy of the uterine cervix was performed after surgery. RESULTS ICG angiography showed that the unilateral uterine artery perfused the bilateral uterine bodies and cervix. In Case 1, ICG angiography showed the occlusion of one of the anastomosed arteries during the operation and the uterus appeared atrophied 2 months after operation. In Case 2, the transplanted uterus survived and normal menstruation occurred. The animal achieved a natural pregnancy and was delivered by the Caeserean section due to early separation of the placenta. The newborn suffered fetal distress. CONCLUSIONS These results show the anastomosis of at least the bilateral uterine arteries and the unilateral ovarian vein is required for uterus transplantation. This is the first report of a natural pregnancy in a primate following uterine autotransplantation.

MicroRNA in cervical cancer: OncomiRs and tumor suppressor miRs in diagnosis and treatment

Cervical cancer is a female-specific disease with a high incidence and mortality. MicroRNAs (miRNAs) are implicated in posttranscriptional regulation of gene expression and in the pathogenic mechanisms of cancer, suggesting their importance in diagnosis and treatment. miRNAs may have roles in the pathogenesis of cervical cancer based on the increases or decreases in several specific miRNAs found in patients with this disease. The miRNAs implicated in cervical cancer are miR-21, miR-126, and miR-143, and clinical application of these miRNAs for diagnosis and treatment is under investigation. Methods for diagnosis of cervical cancer include analysis of changes in the levels of specific miRNAs in serum and determination of aberrant hypermethylation of miRNAs. Supplementation of miR-143 or inhibition of miR-21 activity in vivo may be therapeutic strategy for cervical cancer. Previous approaches to development of siRNA as a drug have provided information for establishment of therapy based on these approaches, and an anti-miR-21 inhibitor has been developed. miRNAs also have effects on drug resistance and may be useful in combination therapy with other drugs.

Uterus autotransplantation in cynomolgus macaques: intraoperative evaluation of uterine blood flow using indocyanine green

BACKGROUND Uterus transplantation may be the only theoretical option for some women, for example, those with congenital uterine infertility or who have undergone hysterectomy. In this study, we evaluated the intra- and post-operative blood flow conditions of vascular anastomosed regions and the blood-perfused area of the transplanted uterus in a cynomolgus macaque model of uterus autotransplantation. METHODS Female cynomolgus monkeys (n = 6) underwent surgery: the first two animals were used to study the pelvic vascular anatomy and the remaining four animals were used for uterus autotransplantation. We used indocyanine green (ICG) fluorescent angiography during surgery to assess blood perfusion in the vascular anastomosed region and uterine area. After surgery, the uterine size, presence or absence of the endometrium and blood flow rates in the uterine artery and vein were evaluated using Doppler ultrasonography. RESULTS; Uterine arterial and venous anastomoses succeeded in all four animals that underwent autotransplantation. Intraoperative ICG fluorescence angiography showed favorable blood flow in the vascular anastomosed regions and the entire uterus received a sufficient blood supply from a single uterine artery. Favorable blood flow in the uterine artery and vein immediately after surgery was shown by Doppler ultrasonography. Ultimately, three out of four animals died within 3 months following surgery because of reduced feeding and loss of body strength. CONCLUSIONS ICG fluorescence angiography can be used for simple evaluation of real-time blood flow conditions in the anastomosed uterine artery, vein and uterine area and can facilitate the success rate of uterus transplantation.

Application of MicroRNA in Diagnosis and Treatment of Ovarian Cancer

Ovarian cancer has a poor prognosis because early detection is difficult and recurrent ovarian cancer is usually drug-resistant. The morbidity and mortality of ovarian cancer are high worldwide and new methods of diagnosis and therapy are needed. MicroRNAs (miRNAs) are posttranscriptional regulators of gene expression that are involved in carcinogenesis, metastasis, and invasion. Thus, miRNAs are likely to be useful as diagnostic and prognostic biomarkers and for cancer therapy. Many miRNAs have altered expression in ovarian cancer compared to normal ovarian tissues and these changes may be useful for diagnosis and treatment. For example, deficiencies of enzymes including Dicer and Drosha that are required for miRNA biogenesis may be adverse prognostic factors; miRNAs such as miR-214 and miR-31, which are involved in drug resistance, and the miR-200 family, which is implicated in metastasis, may serve as biomarkers; and transfection of downregulated miRNAs and inhibition of upregulated miRNAs may be effective for treatment of ovarian cancer. Chemotherapy targeting epigenetic mechanisms associated with miRNAs may also be effective to reverse gene silencing.

Analysis of candidate target genes for mononucleotide repeat mutation in microsatellite instability-high (MSI-H) endometrial cancer.

Microsatellite instability (MSI) is an indicator of DNA instability and is caused by abnormalities in DNA mismatch repair (MMR) genes such as hMLH1, hMSH2 and hMSH6. MSI occurs frequently in endometrial cancer (in approximately 30% of cases), and accumulation of gene mutations due to MSI may therefore have a major role in the mechanism of malignant transformation. However, a responsible target gene has not been identified in endometrial cancer. In this study, we analyzed mutations in 11 cancer-related genes with mononucleotide repeats susceptible to MSI in a coding region [hMSH3 (A8), hMSH6 (C8), TGF-beta RII (A10), MBD4 (A10), BAX (G8), PTEN (A6 in exon 7), HDAC2 (A9), EPHB2 (A9), Caspase-5 (A10), TCF-4 (A9) and Axin2 (G7)] in 22 patients with MSI-H sporadic endometrial cancer. Mutations in hMSH6 (C8) and TGF-beta RII (A10) were found most frequently, at rates of 36.3% (8/22) each. Mutations of BAX (G8) and TCF-4 (A9), which are common in MSI-positive colorectal cancer, occurred at rates of 22.7 and 0%, respectively, which suggests that the MSI target gene may differ between endometrial and colorectal cancers. Mutations in hMSH6 (C8) were correlated with reduced protein expression (p=0.042) and patients with these mutations had significantly more mutations in mononucleotide repeats in other cancer-related genes compared to patients without hMSH6 (C8) mutations (p=0.042). This suggests the possibility of a novel cascade in carcinogenesis of endometrial cancer in which MSI mutates hMSH6 (C8), increases gene instability, and leads to accumulation of mutations in other cancer-related genes. To our knowledge, this is the first report to show that hMSH6 (C8) has an important role as an MSI target gene in sporadic endometrial cancer.

Epigenetics and genetics in endometrial cancer: new carcinogenic mechanisms and relationship with clinical practice

Endometrial cancer is the seventh most common cancer worldwide among females. An increased incidence and a younger age of patients are also predicted to occur, and therefore elucidation of the pathological mechanisms is important. However, several aspects of the mechanism of carcinogenesis in the endometrium remain unclear. Associations with genetic mutations of cancer-related genes have been shown, but these do not provide a complete explanation. Therefore, epigenetic mechanisms have been examined. Silencing of genes by DNA hypermethylation, hereditary epimutation of DNA mismatch repair genes and regulation of gene expression by miRNAs may underlie carcinogenesis in endometrial cancer. New therapies include targeting epigenetic changes using histone deacetylase inhibitors. Some cases of endometrial cancer may also be hereditary. Thus, patients with Lynch syndrome which is a hereditary disease, have a higher risk for developing endometrial cancer than the general population. Identification of such disease-related genes may contribute to early detection and prevention of endometrial cancer.

Epimutation and cancer: a new carcinogenic mechanism of Lynch syndrome (Review)

Epimutation is defined as abnormal transcriptional repression of active genes and/or abnormal activation of usually repressed genes caused by errors in epigenetic gene repression. Epimutation arises in somatic cells and the germline, and constitutional epimutation may also occur. Epimutation is the first step of tumorigenesis and can be a direct cause of carcinogenesis. Cancers associated with epimutation include Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC), chronic lymphocytic leukemia, breast cancer and ovarian cancer. Epimutation has been shown for many tumor suppressor genes, including RB, VHL, hMLH1, APC and BRCA1, in sporadic cancers. Methylation has recently been shown in DNA from normal tissues and peripheral blood in cases of sporadic colorectal cancer and many studies show constitutive epimutation in cancers. Epimutation of DNA mismatch repair (MMR) genes (BRCA1, hMLH1 and hMSH2) involved in development familial cancers has also been found. These results have led to a focus on epimutation as a novel oncogenic mechanism.

Uterus allotransplantation in cynomolgus macaque: A preliminary experience with non‐human primate models

Uterine transplantation (UTx) is a potential option for child‐bearing in women with uterine infertility. Recovery of uterine function after allogeneic UTx in non‐human primates has not been reported. The objective of this study is to establish the functional uterine transplant model in non‐human primates.

Risks for Donors in Uterus Transplantation

Uterus transplantation (UTx) is an alternative to gestational surrogacy and adoption for patients with absolute uterine infertility. Studies have been conducted in animals, and UTx is now within the reach of clinical application in humans. Procedures in humans have been published, but many medical, ethical, and social problems and risks of UTx require discussion prior to widespread clinical application, from the perspectives of donors, recipients, families, and newborns. In this article, we summarize the burdens and risks of UTx, with a focus on donors who provide the uterus.