MMSET/WHSC1 enhances DNA damage repair leading to an increase in resistance to chemotherapeutic agents.

MMSET/WHSC1 is a histone methyltransferase (HMT) overexpressed in t(4;14)+ multiple myeloma (MM) patients, believed to be the driving factor in the pathogenesis of this MM subtype. MMSET overexpression in MM leads to an increase in histone 3 lysine 36 dimethylation (H3K36me2), and a decrease in histone 3 lysine 27 trimethylation (H3K27me3), as well as changes in proliferation, gene expression and chromatin accessibility. Prior work linked methylation of histones to the ability of cells to undergo DNA damage repair. In addition, t(4;14)+ patients frequently relapse after regimens that include DNA damage-inducing agents, suggesting that MMSET may play a role in DNA damage repair and response. In U2OS cells, we found that MMSET is required for efficient non-homologous end joining as well as homologous recombination. Loss of MMSET led to loss of expression of several DNA repair proteins, as well as decreased recruitment of DNA repair proteins to sites of DNA double-strand breaks (DSBs). By using genetically matched MM cell lines that had either high (pathological) or low (physiological) expression of MMSET, we found that MMSET-high cells had increased damage at baseline. Upon addition of a DNA-damaging agent, MMSET-high cells repaired DNA damage at an enhanced rate and continued to proliferate, whereas MMSET-low cells accumulated DNA damage and entered cell cycle arrest. In a murine xenograft model using t(4;14)+ KMS11 MM cells harboring an inducible MMSET shRNA, depletion of MMSET enhanced the efficacy of chemotherapy, inhibiting tumor growth and extending survival. These findings help explain the poorer prognosis of t(4;14) MM and further validate MMSET as a potential therapeutic target in MM and other cancers.

Development of DES-associated clear-cell carcinoma: the importance of regular screening.

Because the rate of malignancies in young women exposed in utero to diethylstilbesterol (DES) is low, appropriate population screening methods have not been established. A case is presented that is believed to represent the first reported instance of a DES-exposed daughter who developed clear cell adenocarcinoma of the vagina after initially negative examinations. The patient was followed with Papanicolaou smears, pelvic examinations, and colposcopy every 6 months for 2 years prior to the discovery of malignancy. Initially negative, Papanicolaou smears successfully predicted the presence of an early adenocarcinoma. Palpation aided by colposcopy allowed directed biopsy of the small asymptomatic lesion. This case underscores the necessity for frequent vaginal cytologic smears and pelvic examinations at intervals no greater than 6 months. Colposcopy is indicated to direct biopsies when an abnormal cytologic smears is reported or when abnormal bleeding or discharge occurs. Biopsy of any palpable lesion is mandatory.

PIP: The value of frequent routine screening of in utero diethylstilbestrol-exposed women has not been established because of lack of documented reports of patients with initially negative examinations who later developed malignancy. LB, a 19-year-old nulligravida with a history of drug exposure in utero, was 1st evaluated for vaginal adenosis at age 15. The patient was followed with Papanicolaou (Pap) smears, pelvic examination, and colposcopy every 6 months for 2 years before malignancy was discovered. After initially negative Pap smears, the patient's smears were classified as Class III 2 years later, and she was referred to the hospital where colposcopy revealed a cervical collar and extensive columnar ectopy covering the entire cervix. A transformation zone, extending onto the upper third of the vagina, showed epithelial and vascular changes characteristic of immature squamous metaplasia. A directed biopsy (aided by palpation) of the area uncovered a clear cell carcinoma. Reactive hyperplasia was present in multiple lymph nodes, and surgery (radical hysterectomy, total vaginectomy, and vaginal reconstruction) was performed. At 24 weeks postoperation, the patient was sexually active and orgasmic, and 1 year postoperation was clinically free of disease, asymptommatic, and enrolled in college, where follow-up continues. This case underscores the necessity for frequent vaginal cytologic smears and pelvic examinations at intervals no greater than 6 months. Biopsy of any palpable lesion is mandatory.

Psychosocial-sexual issues.

The female breast is discussed in terms of cultural, psychosocial, and sexual aspects. These elements are significant in medical and surgical management of breast disease and have relevance in the resulting quality of life for female patients.

Practical aspects of full-time liaison psychiatry in gynecology.

A full-time liason psychiatrist can work within a department of obstetrics and gynecology. The full-time position described here includes administrative, clinical, teaching and research aspects within a general hospital affiliated with a medical school. The liason role can be established within a department outside psychiatry where medical and psychologic treatment can be rendered to patients simultaneously and the mediating role between psychiatry and medicine is truly a viable phenomenon.

Psychosocial issues in breast disease.

The awareness of cultural and psychosocial factors and attitudes toward the breast and the inclusion of these factors in the total care of the patient facilitates management of breast disease to the benefit of the patient, her family, the medical staff, and, ultimately, to society as a whole.

Ovarian carcinoma: management of stress in patients and physicians.

A discussion of the management of ovarian cancer invariably involves the problems of death and dying faced by the patient, her family, and her physician. This paper attempts to deal with the general fears, anxieties, and problems of terminality, and also places attention on specific issues involved in living with the ongoing disease and its treatments. Focus is on the effects of the disease on the woman's self-image, on her family and relationships, on life outside the hospital, and on her relationship with her attending physician. Specific problems relating to the periods of (1) diagnosis, (2) operative management and treatment, and (3) terminality are discussed. Understanding the psychosocial realities of the patient provides the physician with added insights into methods to assist the patient in adaptation and coping with this ultimately fatal disease.

Development and validation of a competitive AKT serine/threonine kinase fluorescence polarization assay using a product-specific anti-phospho-serine antibody.

A competitive fluorescence polarization (FP) assay has been developed for the serine/threonine kinase, AKT. The FP assay has been formatted in a 384-well microtiter plate and automated using a pipeting workstation with performance suitable for high-throughput screening. The assay design utilizes a fluorescent phosphorylated peptide complexed to a product-specific anti-phospho-serine antibody. When unlabeled substrate is phosphorylated, by the kinase, the product competes with the fluorescent phosphorylated peptide for the antibody. The fluorescent phosphorylated peptide is then released from the antibody into solution resulting in a loss in polarization signal. Seven fluorescent phosphorylated peptides and 19 antibodies were evaluated for this assay. RARTSpSFAEPGK-Fl peptide and anti-phospho-GSK-3alpha Ser21 antibody gave the best affinity and change in polarization signal. The apparent kinetic constants were calculated for the FP assay and were consistent with reported values. The FP assay was validated with known inhibitors and the results compared to a radioactive Flashplate transfer assay, utilizing [(33)P]ATP and a biotinylated substrate, also developed in our laboratory. The IC(50) values generated were comparable between the two methods suggesting the competitive FP assay and Flashplate assay have similar sensitivities and abilities to identify inhibitors during screening.