Clyde D. Ford

Histone deacetylase inhibitors induce G2-checkpoint arrest and apoptosis in cisplatinum-resistant ovarian cancer cells associated with overexpression of the Bcl-2–related protein Bad

Trichostatin A produces predominantly G1 cell-cycle blockade and differentiation of the cisplatinum-sensitive A2780 ovarian cancer cell line. Given the propensity of ovarian tumors to become resistant to cisplatinum, often leading to cross-resistance to other agents, we have extended these observations by examining how the emergence of resistant phenotypes in A2780 cells affects the actions of histone deacetylase (HDAC) inhibitors. Trichostatin A exposure (100 ng/mL, 24 hours) induced ultrastructural differentiation of the “intrinsically” cisplatinum-resistant A2780-9M subline, with the reappearance of intercellular junctions and lumina containing primitive microvilli. Similar trichostatin A exposure in the acquired resistance A2780CP cells produced minimal differentiation consisting of occasional weak intercellular junctions. Independent of the differences in trichostatin A–induced differentiation, in both resistant sublines trichostatin A produced a similar reduction in cell viability, by >90%, within 5 days of treatment. Diminished viability in both A2780-9M and CP cells was associated with the absence of cell cycle arrest in G1, resulting in predominant G2-checkpoint arrest accompanied by a 10- to 20-fold increase in Annexin V binding and the reemergence of apoptosis. Similar cell cycle arrests and apoptosis were also observed using other HDAC inhibitors and in other resistant ovarian cancer cell lines (OVCAR-3 and SK-OV-3). Trichostatin A–induced apoptosis in resistant cells is in sharp contrast to its effects on the parental cisplatinum-sensitive A2780 and normal MRC-5 fibroblast cell lines (predominant cycle arrest in G1 with no detectable apoptosis). Western immunoblot analysis indicated trichostatin A triggers apoptosis in resistant ovarian cancer cells via p53-independent activation of the intrinsic “mitochondrial” pathway, commensurate with induction of the Bcl-2–related protein Bad. These results suggest cisplatinum resistance alters the effects of HDAC inhibition through a shift in cell cycle arrest from the G1 to the G2 checkpoint and reactivation of the intrinsic mitochondrial apoptotic cascade.

Fecal microbiota transplantation for recurrent Clostridium difficile infection in hematopoietic stem cell transplant recipients.

Recurrent Clostridium difficile infection (CDI) is a consequence of intestinal dysbiosis and is particularly common following hematopoietic stem cell transplantation (HSCT). Fecal microbiota transplantation (FMT) is an effective method of treating CDI by correcting intestinal dysbiosis by passive transfer of healthy donor microflora. FMT has not been widely used in immunocompromised patients, including HSCT recipients, owing to concern for donor‐derived infection. Here, we describe initial results of an FMT program for CDI at a US HSCT center. Seven HSCT recipients underwent FMT between February 2015 and February 2016. Mean time post HSCT was 635 days (25–75 interquartile range [IQR] 38–791). Five of the patients (71.4%) were on immunosuppressive therapy at FMT; 4 had required long‐term suppressive oral vancomycin therapy because of immediate recurrence after antibiotic cessation. Stool donors underwent comprehensive health and behavioral screening and laboratory testing of serum and stool for 32 potential pathogens. FMT was administered via the naso‐jejunal route in 6 of the 7 patients. Mean follow‐up was 265 days (IQR 51–288). Minor post‐FMT adverse effects included self‐limited bloating and urgency. One patient was suspected of having post‐FMT small intestinal bacterial overgrowth. No serious adverse events were noted and all‐cause mortality was 0%. Six of 7 (85.7%) patients had no recurrence; 1 patient recurred at day 156 post FMT after taking an oral antibiotic and required repeat FMT, after which no recurrence has occurred. Diarrhea was improved in all patients and 1 patient with gastrointestinal graft‐versus‐host disease was able to taper off systemic immunosuppression after FMT. With careful donor selection and laboratory screening, FMT appears to be a safe and effective therapy for CDI in HSCT patients and may confer additional benefits. Larger studies are necessary to confirm safety and efficacy and explore other possible effects.

Natural killer cells in in utero diethylstilbesterol-exposed patients

The observations that limited neonatal diethylstilbesterol (DES) exposure in mice produces persistent natural killing defects and that natural killer (NK) cells have an origin early in gestation suggested the possibility that NK abnormalities may exist in in utero DES-exposed women. However, when compared to controls, these women showed slightly higher NK activity with no evidence of stimulation by accessory mononuclear cells. Altered natural killing cannot be invoked in this population as a contributing factor to increased cancer risk.

False-positive restaging PET scans involving the spleen in two patients with aggressive non-Hodgkin lymphoma.

We report 2 patients with aggressive non-Hodgkin lymphoma who had positive restaging PET scans limited to the spleen and no significant uptake in nodal areas of previously known disease. Examination of the resected spleens from both patients revealed extensive inflammation surrounding necrotic tumor with no evidence of viable lymphoma or active infection. It is suggested that close observation of such patients for evidence of progressive disease may be considered as opposed to immediate intervention.

The clinical impact of vancomycin‐resistant Enterococcus colonization and bloodstream infection in patients undergoing autologous transplantation

Although several studies have documented adverse outcomes for vancomycin‐resistant Enterococcus (VRE) colonization and infection in allogeneic hematopoietic stem cell transplantation (allo‐HSCT) recipients, data are inadequate for patients undergoing autologous (auto‐)HSCT.

Vancomycin-Resistant Enterococcus Colonization and Bacteremia and Hematopoietic Stem Cell Transplantation Outcomes

The association between pre-hematopoietic stem cell transplantation (HSCT) vancomycin-resistant Enterococcus (VRE) colonization, HSCT-associated VRE bacteremia, and HSCT mortality is disputed. We studied 161 consecutive patients with acute leukemia who underwent HSCT at our hospital between 2006 and 2014, of whom 109 also received leukemia induction/consolidation on our unit. All inpatients had weekly VRE stool surveillance. Pre-HSCT colonization was not associated with increases in HSCT mortality but did identify a subgroup of HSCT recipients with a higher risk for VRE bacteremia and possibly bacteremia from other organisms. The major risk factor for pre-HSCT colonization was the number of hospital inpatient days between initial admission for leukemia and HSCT. One-third of evaluable patients colonized before HSCT were VRE-culture negative on admission for HSCT; these patients had an increased risk for subsequent VRE stool surveillance positivity but not VRE bacteremia. Molecular typing of VRE isolates obtained before and after HSCT showed that VRE strains frequently change. Postengraftment VRE bacteremia was associated with a much higher mortality than pre-engraftment VRE bacteremia. Pre-engraftment bacteremia from any organism was associated with an alternative donor and resulted in an increase in hospital length of stay and cost. Mortality was similar for pre-engraftment VRE bacteremia and pre-engraftment bacteremia due to other organisms, but mortality associated with post-engraftment VRE bacteremia was higher and largely explained by associated severe graft-versus-host disease and relapsed leukemia. These data emphasize the importance of distinguishing between VRE colonization before HSCT and at HSCT, between pre-engraftment and postengraftment VRE bacteremia, and between VRE bacteremia and bacteremia from other organisms.

Room contamination, patient colonization pressure, and the risk of vancomycin-resistant Enterococcus colonization on a unit dedicated to the treatment of hematologic malignancies and hematopoietic stem cell transplantation

BACKGROUND Contaminated surfaces and colonization pressure are risk factors for vancomycin-resistant Enterococcus (VRE) colonization in intensive care units (ICUs). Whether these apply to modern units dedicated to the care of hematologic malignancies and hematopoietic stem cell transplant (HSCT) procedures is unknown. METHODS We reviewed the records of 780 consecutive admissions for acute leukemia, autologous HSCT, or allogeneic HSCT in which the patient was at risk for hospital-acquired VRE and underwent weekly surveillance. We also obtained staff and room cultures, observed staff behavior, and performed VRE molecular strain typing on selected isolates. RESULTS The overall rate of VRE colonization was 11.4 cases/1,000 patient days. Cultures of room surfaces revealed VRE isolates in 10% of terminally cleaned rooms. A prior VRE-colonized room occupant did not increase risk, and paired isolates from 20 patients and prior occupants were indistinguishable on molecular typing in only 1 pair. VRE colonization pressure was significantly associated with acquisition. Cultures of unit personnel and shared equipment were negative except for weighing scales. Observation of unit clinical personnel showed high compliance for hand sanitation and but less so for gowns. Conversely, ancillary staff showed poor compliance. CONCLUSIONS Transmission of VRE from room surfaces seems to be an infrequent event. Encouraging adherence to surveillance, disinfection, and contact isolation protocols may decrease VRE colonization rates.

Repurposing an Old Drug for a New Epidemic: Ursodeoxycholic Acid to Prevent Recurrent Clostridioides difficile Infection

Recurrent Clostridioides difficile infection (rCDI) may be mediated in part by secondary bile acids. Here we report salvage therapy with ursodeoxycholic acid (UDCA) to prevent rCDI in 16 high-risk patients. Patients on UDCA had a low observed recurrence rate (12.5%). Controlled trials are needed to confirm these observations.

A population-based study of patterns of care for ovarian cancer: Who is seen by a gynecologic oncologist and who is not?

This study presents a comparison of the outcomes of patients with epithelial ovarian cancer who did and did not receive care from a gynecologic oncologist. The medical records of 848 women, identified from the Utah CancerRegistry, who were diagnosed with epithelial ovarian cancer between 1992 and 1998 were reviewed for relevant clinical and social information. Nearly 80% of the women lived in one of the four metropolitan areas in Utah. A gynecologic oncologist was involved in the diagnosis or treatment of 39% of the women. This percentage increased over the 6 years of the study, from 33% in the first year to 47.5% in the final year. Women between the ages of 40 and 60 years and urban-dwelling women were more likely to have seen a gynecologic oncologist during the course of their disease (P <.01 for both) compared with those younger or older or who resided in rural areas. The majority of the patients were diagnosed with regional (N = 117) or distant (N = 455) stage disease, and 244 had local disease at the time of diagnosis. The stage was unknown in 32 patients, only 3 of whom were among those seen by a gynecologic oncologist. In the 455 patients with distant metastases, there was a statistically significant difference in the survival rates of women who did and did not have a gynecologic oncologist involved in their care (median survival, 26 and 16 months, respectively; P =.0012 unadjusted for age). For patients with local or regional disease (unadjusted for age), there was no statistically significant difference in survival. Patients who were older than 70 years at diagnosis had a significantly longer survival than those younger than 70 years (median survival, 25 and 13 months, respectively, P =.0092). When adjusted for age, survival was significantly longer for older women with distant disease who had seen a gynecologic oncologist compared with those who had not (median survival, 15 and 8 months, respectively; P =.0467).

Opposing effects of human peripheral blood lymphocytes on the growth of cultured leukemia cell lines

Abstract Natural killing of two human leukemia cell lines (K562 and Molt 4) in a soft-agar, clonagenic assay was shown to be the result of two opposite yet concurrent processes: target cell colony stimulation and inhibition. The stimulatory effect was demonstrable when the effector lymphocytes and target cells were separated in contiguous agar layers, suggesting mediation by a soluble factor. Similarly, stimulation occurred when the effector lymphocytes and target cells were combined at low effector-target cell ratios that do not favor direct cell contact. Target colony inhibition was found to be dominant when large E:T ratios were employed. Both target-effector binding and natural killing were significantly reduced in medium devoid of divalent cations.