Bone Marrow Quality Index: A Predictor of Acute Graft-versus-Host Disease in Hematopoietic Stem Cell Transplantation for Thalassemia.

Bone marrow (BM) continues to be the preferred source of stem cells in allogenic transplantation for nonmalignant disorders. Granulocyte colony-stimulating factor (G-CSF)-primed BM is associated with low rates of acute graft-versus-host disease (aGVHD) and allows reduced collection volumes while ensuring speedy engraftment. However, variability in BM harvest quality is a concern. This study evaluated the utility of a novel indicator, the Bone Marrow Quality Index (BMQI), to predict aGVHD. We analyzed 184 consecutive first matched related donor bone marrow transplants for thalassemia using G-CSF-primed bone marrow over 6 years from March 2017 to April 2023 across 2 centers in India. BMQI was defined as the ratio of the G-CSF-primed BM WBC count to the peripheral blood WBC count within 24 hours of harvest. European Society for Blood and Marrow Transplantation criteria were used to grade aGVHD. The log-rank test was used to assess the impact of BMQI on aGVHD. The chi-square test was used to compare categorical data, and the Wilcoxon rank-sum test was used to compare the numerical data. A Cox proportional hazards model was used to investigate the association of BMQI vis-à-vis other factors on aGVHD. Of the 184 patients studied, 19 had a BMQI <.9, 18 had a BMQI between .9 and 1, and the remaining 147 had a BMQI >1. The rate of aGVHD grade II-IV was 37% in patients with a BMQI <.9 , 22% in those with BMQI .9 to 1, and 12% in those with BMQI >1 (P = .018). Patients with BMQI <.9 had a 3.1-fold greater chance (95% confidence interval [CI], .9 to 10.6) and those with BMQI .9 to 1 had a 2-fold greater chance (95% CI, .5 to 6.6) of developing aGVHD grade II-IV. BMQI was the significant predictor associated with aGVHD hazard (P = .014). BMQI appears to be the most relevant and controllable predictor of aGVHD. It is a novel, informative, and very simple indicator that could influence aGVHD prophylaxis decision making. Our indicator is accurately measurable, inexpensive, precise, and timely; furthermore, it does not involve any sophisticated equipment and thus may be widely applicable. Prior knowledge of poor BM quality may help intensify prophylaxis and monitoring for aGVHD, as well as trigger a review of collection procedures.

Do Weekly Surveillance Cultures Contribute to Antibiotic Stewardship and Correlate with Outcome of HSCT in Children? A Multicenter Real-World Experience of 5 Years from the Indian Subcontinent.

The utility of weekly rectal swab surveillance cultures (RSSCs) as a resource to identify gut colonization with extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli or Klebsiella pneumoniae carbapenemase (KPC)-producing organisms and guide empirical antibiotic therapy in hematopoietic stem cell transplantation (HSCT) recipients continues to be a subject of interest. There is an urgent need to assess and justify modifications to empirical antibiotics based on regional epidemiology and patient groups. This study aimed to study the utility of weekly rectal swab surveillance cultures (RSSCs) to guide empirical antibiotic therapy and to examine the impact of gut colonization on transplantation outcomes. This retrospective analysis of 317 successive first HSCTs performed mainly for hemoglobinopathies was conducted in 3 pediatric bone marrow transplantation centers in the Indian subcontinent between April 2016 and April 2021. Transplantation, infection control, and febrile neutropenia management protocols were identical in the 3 centers. First-line antibiotics were chosen based on RCCS reports, with meropenem used for ESBL and high-dose meropenem with colistin used for carbapenemase-resistant colonization for first half of the study, with no adjustment made in the second half. Clinical response to antibiotics, long-term outcomes, antibiotic-resistant bacteremia, and acute graft-versus-host disease (GVHD) were analyzed. The log-rank test, chi-square, and Wilcoxon rank-sum tests were used to compare data using R Statistical software. Of the 871 weekly RSSCs done, 162 were positive for ESBL- or KPC-resistant organism. RCCSs were ESBL-positive in 106 patients (33%) and KPC-positive in 10 patients (3%). Among the 97 ESBL-positive patients for whom a antimicrobial susceptibility testing report was available, only 22 (25%) demonstrated clinical resistance to piperacillin-tazobactam (Pip-Taz). Among the 10 KPC-positive patients, only 4 (40%) demonstrated clinical resistance to Pip-Taz and 3 (30%) had clinical resistance to meropenem. Two-thirds of patients with ESBL-positive RSSC in whom first-line empirical antibiotics were used responded clinically. Even among the 15 patients who were resistant to first-line empirical antibiotics (Pip-Taz) on RSSC reports, 67% responded clinically to Pip-Taz. Twenty-seven of these patients (56%) never needed carbapenem therapy. Empirical Pip-Taz therapy in ESBL-positive patients did not prolong meropenem use within 100 days of transplantation (P = .18). All patients with a KPC-positive RSSC who received first-line empirical antibiotics responded clinically, including 4 who were resistant to Pip-Taz and 3 who were meropenem-resistant on RCCS. Comparing patients who were ESBL-positive, KPC-positive, and not positive for either showed no statistically significant differences in overall survival (OS) (P = .95), disease-free survival (DFS) (P = .45), transplantation-related mortality (TRM) (P = .97), graft rejection (P = .68), or rate of acute GVHD grade II-IV (P = .78). No statistically significant differences were seen between the ESBL-positive patients who received and those who did not receive higher-level empirical antibiotics in OS (P = .32), DFS (P = .64), TRM (P = .65), graft rejection (P = .46), acute GVHD grade II-IV (P = .26), or antibiotic-resistant bacteremia (P = .3). In the context of HSCT for nonmalignant hematologic disorders, choosing empiric antibiotic therapy based on RSSCs is not justified, even in regions with a high prevalence of antimicrobial resistance. Antimicrobial susceptibility testing reports in surveillance cultures did not correlate with in vivo clinical response. Colonization reported on weekly RSSCs showed no correlation with clinical outcomes. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Targeted Inhibition of ULK1 Promotes Apoptosis and Suppresses Tumor Growth and Metastasis in Neuroblastoma.

Neuroblastoma is the most common extracranial solid malignancy in the pediatric population, accounting for over 9% of all cancer-related deaths in children. Autophagy is a cell self-protective mechanism that promotes tumor cell growth and survival, making it an attractive target for treating cancer. However, the role of autophagy in neuroblastoma tumor growth and metastasis is largely undefined. Here we demonstrate that targeted inhibition of an essential autophagy kinase, unc-51 like autophagy kinase 1 (ULK1), with a recently developed small-molecule inhibitor of ULK1, SBI-0206965, significantly reduces cell growth and promotes apoptosis in SK-N-AS, SH-SY5Y, and SK-N-DZ neuroblastoma cell lines. Furthermore, inhibition of ULK1 by a dominant-negative mutant of ULK1 (dnULK1K46N) significantly reduces growth and metastatic disease and prolongs survival of mice bearing SK-N-AS xenograft tumors. We also show that SBI-0206965 sensitizes SK-N-AS cells to TRAIL treatment, but not to mTOR inhibitors (INK128, Torin1) or topoisomerase inhibitors (doxorubicin, topotecan). Collectively, these findings demonstrate that ULK1 is a viable drug target and suggest that inhibitors of ULK1 may provide a novel therapeutic option for the treatment of neuroblastoma. Mol Cancer Ther; 17(11); 2365-76. ©2018 AACR.

Selective Reversible Inhibition of Autophagy in Hypoxic Breast Cancer Cells Promotes Pulmonary Metastasis.

Autophagy influences how cancer cells respond to nutrient deprivation and hypoxic stress, two hallmarks of the tumor microenvironment (TME). In this study, we explored the impact of autophagy on the pathophysiology of breast cancer cells using a novel hypoxia-dependent, reversible dominant-negative strategy to regulate autophagy at the cellular level within the TME. Suppression of autophagy via hypoxia-induced expression of the kinase-dead unc-51-like autophagy-activating kinase (ULK1) mutant K46N increased lung metastases in MDA-MB-231 xenograft mouse models. Consistent with this effect, expressing a dominant-negative mutant of ULK1 or ATG4b or a ULK1-targeting shRNA facilitated cell migration in vitro Functional proteomic and transcriptome analysis revealed that loss of hypoxia-regulated autophagy promotes metastasis via induction of the fibronectin integrin signaling axis. Indeed, loss of ULK1 function increased fibronectin deposition in the hypoxic TME. Together, our results indicated that hypoxia-regulated autophagy suppresses metastasis in breast cancer by preventing tumor fibrosis. These results also suggest cautions in the development of autophagy-based strategies for cancer treatment. Cancer Res; 77(3); 646-57. ©2016 AACR.