Quiescent Ovarian Cancer Cells Secrete Follistatin to Induce Chemotherapy Resistance in Surrounding Cells in Response to Chemotherapy.

PURPOSE: We recently reported that the transcription factor NFATC4, in response to chemotherapy, drives cellular quiescence to increase ovarian cancer chemoresistance. The goal of this work was to better understand the mechanisms of NFATC4-driven ovarian cancer chemoresistance. EXPERIMENTAL DESIGN: We used RNA sequencing to identify NFATC4-mediated differential gene expression. CRISPR-Cas9 and FST (follistatin)-neutralizing antibodies were used to assess impact of loss of FST function on cell proliferation and chemoresistance. ELISA was used to quantify FST induction in patient samples and in vitro in response to chemotherapy. RESULTS: We found that NFATC4 upregulates FST mRNA and protein expression predominantly in quiescent cells and FST is further upregulated following chemotherapy treatment. FST acts in at least a paracrine manner to induce a p-ATF2-dependent quiescent phenotype and chemoresistance in non-quiescent cells. Consistent with this, CRISPR knockout (KO) of FST in ovarian cancer cells or antibody-mediated neutralization of FST sensitizes ovarian cancer cells to chemotherapy treatment. Similarly, CRISPR KO of FST in tumors increased chemotherapy-mediated tumor eradication in an otherwise chemotherapy-resistant tumor model. Suggesting a role for FST in chemoresistance in patients, FST protein in the abdominal fluid of patients with ovarian cancer significantly increases within 24 hours of chemotherapy exposure. FST levels decline to baseline levels in patients no longer receiving chemotherapy with no evidence of disease. Furthermore, elevated FST expression in patient tumors is correlated with poor progression-free, post-progression-free, and overall survival. CONCLUSIONS: FST is a novel therapeutic target to improve ovarian cancer response to chemotherapy and potentially reduce recurrence rates.

NFATC4 promotes quiescence and chemotherapy resistance in ovarian cancer.

Development of chemotherapy resistance is a major problem in ovarian cancer. One understudied mechanism of chemoresistance is the induction of quiescence, a reversible nonproliferative state. Unfortunately, little is known about regulators of quiescence. Here, we identify the master transcription factor nuclear factor of activated T cells cytoplasmic 4 (NFATC4) as a regulator of quiescence in ovarian cancer. NFATC4 is enriched in ovarian cancer stem-like cells and correlates with decreased proliferation and poor prognosis. Treatment of cancer cells with cisplatin resulted in NFATC4 nuclear translocation and activation of the NFATC4 pathway, while inhibition of the pathway increased chemotherapy response. Induction of NFATC4 activity resulted in a marked decrease in proliferation, G0 cell cycle arrest, and chemotherapy resistance, both in vitro and in vivo. Finally, NFATC4 drove a quiescent phenotype in part via downregulation of MYC. Together, these data identify NFATC4 as a driver of quiescence and a potential new target to combat chemoresistance in ovarian cancer.

Detection of Cytomegalovirus in Intestinal Tissue of Infants with Necrotizing Enterocolitis or Spontaneous Intestinal Perforation.

OBJECTIVE: To determine the frequency of detection of cytomegalovirus (CMV) in surgical or autopsy intestinal tissue from infants with necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP) of the small bowel. STUDY DESIGN: This was a retrospective cohort study of infants in the neonatal intensive care unit at Nationwide Children's Hospital, Columbus, Ohio, with NEC (Bell stage ≥2B) or SIP from 2000 to 2016. Paraffin-embedded surgical or autopsy intestinal tissues were examined for CMV by polymerase chain reaction (PCR) and immunohistochemistry (IHC), and clinical characteristics of CMV-positive vs CMV-negative cases were compared. RESULTS: CMV was detected by PCR or IHC in 7 (4%) of 178 infants with surgical or autopsy- confirmed NEC (n = 6) or SIP (n = 1). Among 143 NEC cases (123 surgical, 20 autopsy), CMV was detected in 6 (4%): 4 (2 surgical, 2 autopsy) by both PCR and IHC, and 2 (surgical) by PCR only. Among 35 SIP cases (32 surgical, 3 autopsy), 1 (3%) surgical case was positive, by PCR only. CMV-associated NEC cases had lower median gestational age (24 vs 28 weeks; P = .02), birth weight (649 vs 1121 g; P = .04), and platelet count (16 000/mm3 vs 50 000/mm3; P = .018) compared with CMV-negative cases, respectively. No association was found with receipt of maternal milk, age at NEC diagnosis, male sex, cholestasis, or mortality. CONCLUSIONS: CMV was detected in intestinal tissue from 4% of NEC or SIP cases (NEC, 4%; SIP, 3%). Lower gestational age, lower birth weight, and thrombocytopenia were significantly associated with detection of CMV in NEC or SIP cases.

Trypanosoma cruzi Detection in Colombian Patients with a Diagnosis of Esophageal Achalasia.

Achalasia is a motility disorder of the esophagus that might be secondary to a chronic Trypanosoma cruzi infection. Several studies have investigated esophageal achalasia in patients with Chagas disease (CD) in Latin America, but no related studies have been performed in Colombia. The goals of the present study were to determine the presence of anti-T. cruzi antibodies in patients with esophageal achalasia who visited a referral hospital in Bogotá, Colombia, and to detect the presence of the parasite and its discrete typing units (DTUs). This cross-sectional study was conducted in adult patients (18-65 years old) who were previously diagnosed with esophageal achalasia and from whom blood was drawn to assess antibodies against T. cruzi using four different serological tests. Trypanosoma cruzi DNA was detected by conventional polymerase chain reaction (cPCR) and quantitative polymerase chain reaction (qPCR). In total, 38 patients, with an average age of 46.6 years (standard deviation of ±16.2) and comprising 16 men and 22 women, were enrolled. Five (13.15%) patients were found to be positive for anti-T. cruzi antibodies by indirect immunofluorescence assay (IFA), and two patients who were negative according to IFA were reactive by both enzyme-linked immunosorbent assay and immunoblot (5.3%). Parasite DNA was detected in two of these seven patients by cPCR and in one of these by qPCR. The parasite DTU obtained was TcI. In summary, this study identified T. cruzi in Colombian patients with esophageal achalasia, indicating that digestive compromise could also be present in patients with chronic CD.