Evaluation of stored red blood cell quality after washing using immune indices.

Washed red blood cells (RBCs) can be used to treat immune-related diseases. However, whether the washing process changes the quality of RBCs and affects the curative effect of transfusion therapy remains unclear. We retrospectively analysed the clinical data of patients who received blood transfusion. The physiological and biochemical parameters of RBCs were tested on an automated haematology-biochemical analyser. CD47 and phosphatidylserine (PS) plasma membrane expression were analysed using flow cytometry. Morphological changes in RBCs were observed using scanning electron microscopy. The results showed that the curative effect on patients who received washed RBCs was weaker than that on those who received non-washed RBCs. Physiological and biochemical parameters of RBCs were not significantly different. RBC immune indices changed significantly after washing. The expression of "don't eat me" signals was weakened, whereas the intensity of "eat me" signals was enhanced. This study suggests that the current use of physiological and biochemical parameters as indicators to evaluate the quality of RBCs may not be comprehensive and that evaluation of the real status of RBCs requires other effective parameters. Immune molecules in RBCs are expected to become supplementary markers for evaluating RBC quality.

Cell Line-Specific Network Models of ER+ Breast Cancer Identify Potential PI3Kα Inhibitor Resistance Mechanisms and Drug Combinations.

Durable control of invasive solid tumors necessitates identifying therapeutic resistance mechanisms and effective drug combinations. In this work, we used a network-based mathematical model to identify sensitivity regulators and drug combinations for the PI3Kα inhibitor alpelisib in estrogen receptor positive (ER+) PIK3CA-mutant breast cancer. The model-predicted efficacious combination of alpelisib and BH3 mimetics, for example, MCL1 inhibitors, was experimentally validated in ER+ breast cancer cell lines. Consistent with the model, FOXO3 downregulation reduced sensitivity to alpelisib, revealing a novel potential resistance mechanism. Cell line-specific sensitivity to combinations of alpelisib and BH3 mimetics depended on which BCL2 family members were highly expressed. On the basis of these results, newly developed cell line-specific network models were able to recapitulate the observed differential response to alpelisib and BH3 mimetics. This approach illustrates how network-based mathematical models can contribute to overcoming the challenge of cancer drug resistance. SIGNIFICANCE: Network-based mathematical models of oncogenic signaling and experimental validation of its predictions can identify resistance mechanisms for targeted therapies, as this study demonstrates for PI3Kα-specific inhibitors in breast cancer.

Acquired FGFR and FGF Alterations Confer Resistance to Estrogen Receptor (ER) Targeted Therapy in ER+ Metastatic Breast Cancer.

PURPOSE: To identify clinically relevant mechanisms of resistance to ER-directed therapies in ER+ breast cancer. EXPERIMENTAL DESIGN: We conducted a genome-scale functional screen spanning 10,135 genes to investigate genes whose overexpression confer resistance to selective estrogen receptor degraders. In parallel, we performed whole-exome sequencing in paired pretreatment and postresistance biopsies from 60 patients with ER+ metastatic breast cancer who had developed resistance to ER-targeted therapy. Furthermore, we performed experiments to validate resistance genes/pathways and to identify drug combinations to overcome resistance. RESULTS: Pathway analysis of candidate resistance genes demonstrated that the FGFR, ERBB, insulin receptor, and MAPK pathways represented key modalities of resistance. The FGFR pathway was altered via FGFR1, FGFR2, or FGF3 amplifications or FGFR2 mutations in 24 (40%) of the postresistance biopsies. In 12 of the 24 postresistance tumors exhibiting FGFR/FGF alterations, these alterations were acquired or enriched under the selective pressure of ER-directed therapy. In vitro experiments in ER+ breast cancer cells confirmed that FGFR/FGF alterations led to fulvestrant resistance as well as cross-resistance to the CDK4/6 inhibitor palbociclib. RNA sequencing of resistant cell lines demonstrated that FGFR/FGF induced resistance through ER reprogramming and activation of the MAPK pathway. The resistance phenotypes were reversed by FGFR inhibitors, a MEK inhibitor, and/or a SHP2 inhibitor. CONCLUSIONS: Our results suggest that FGFR pathway is a distinct mechanism of acquired resistance to ER-directed therapy that can be overcome by FGFR and/or MAPK pathway inhibitors.

The Genomic Landscape of Intrinsic and Acquired Resistance to Cyclin-Dependent Kinase 4/6 Inhibitors in Patients with Hormone Receptor-Positive Metastatic Breast Cancer.

Mechanisms driving resistance to cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in hormone receptor-positive (HR+) breast cancer have not been clearly defined. Whole-exome sequencing of 59 tumors with CDK4/6i exposure revealed multiple candidate resistance mechanisms including RB1 loss, activating alterations in AKT1, RAS, AURKA, CCNE2, ERBB2, and FGFR2, and loss of estrogen receptor expression. In vitro experiments confirmed that these alterations conferred CDK4/6i resistance. Cancer cells cultured to resistance with CDK4/6i also acquired RB1, KRAS, AURKA, or CCNE2 alterations, which conferred sensitivity to AURKA, ERK, or CHEK1 inhibition. Three of these activating alterations-in AKT1, RAS, and AURKA-have not, to our knowledge, been previously demonstrated as mechanisms of resistance to CDK4/6i in breast cancer preclinically or in patient samples. Together, these eight mechanisms were present in 66% of resistant tumors profiled and may define therapeutic opportunities in patients. SIGNIFICANCE: We identified eight distinct mechanisms of resistance to CDK4/6i present in 66% of resistant tumors profiled. Most of these have a therapeutic strategy to overcome or prevent resistance in these tumors. Taken together, these findings have critical implications related to the potential utility of precision-based approaches to overcome resistance in many patients with HR+ metastatic breast cancer.This article is highlighted in the In This Issue feature, p. 1079.

Headway and hurdles in the clinical development of dietary phytochemicals for cancer therapy and prevention: lessons learned from vitamin A derivatives.

Accumulating epidemiologic and preclinical evidence support the pharmacologic use of a variety of dietary chemicals for the prevention and treatment of cancer. However, it will be challenging to translate these findings into routine clinical practice since phytochemicals have pleiotropic biological activities that have to be balanced for optimal efficacy without unacceptable and potentially unanticipated toxicities. Correctly matching patient populations and settings with optimal, natural product-based phytochemical therapies will require a greater understanding of the specific mechanisms underlying the efficacy, toxicity, and resistance of each agent in a variety of normal, premalignant, and malignant settings. This, in turn, necessitates continued commitment from the basic research community to guide carefully designed and informed clinical trials. The most developed class of anticancer phytochemicals consists of the derivatives of vitamin A called retinoids. Unlike other natural product chemicals currently under study, the retinoids have been extensively tested in humans. Over 30 years of clinical investigation has resulted in several disappointments, but there were some spectacular successes where certain retinoid-based protocols are now FDA-approved standard of care therapies to treat specific malignancies. Furthermore, retinoids are one of the most evaluated pharmacologic agents in the ultra-challenging setting of interventional cancer prevention. This review will summarize the development of retinoids in cancer therapy and prevention with an emphasis on currently proposed mechanisms mediating their efficacy, toxicity, and resistance.

Serine/threonine kinase 17A is a novel candidate for therapeutic targeting in glioblastoma.

STK17A is a relatively uncharacterized member of the death-associated protein family of serine/threonine kinases which have previously been associated with cell death and apoptosis. Our prior work established that STK17A is a novel p53 target gene that is induced by a variety of DNA damaging agents in a p53-dependent manner. In this study we have uncovered an additional, unanticipated role for STK17A as a candidate promoter of cell proliferation and survival in glioblastoma (GBM). Unexpectedly, it was found that STK17A is highly overexpressed in a grade-dependent manner in gliomas compared to normal brain and other cancer cell types with the highest level of expression in GBM. Knockdown of STK17A in GBM cells results in a dramatic alteration in cell shape that is associated with decreased proliferation, clonogenicity, migration, invasion and anchorage independent colony formation. STK17A knockdown also sensitizes GBM cells to genotoxic stress. STK17A overexpression is associated with a significant survival disadvantage among patients with glioma which is independent of age, molecular phenotype, IDH1 mutation, PTEN loss, and alterations in the p53 pathway and partially independent of grade. In summary, we demonstrate that STK17A provides a proliferative and survival advantage to GBM cells and is a potential target to be exploited therapeutically in patients with glioma.

Serine/threonine kinase 17A is a novel p53 target gene and modulator of cisplatin toxicity and reactive oxygen species in testicular cancer cells.

Testicular cancer is highly curable with cisplatin-based therapy, and testicular cancer-derived human embryonal carcinoma (EC) cells undergo a p53-dominant transcriptional response to cisplatin. In this study, we have discovered that a poorly characterized member of the death-associated protein family of serine/threonine kinases, STK17A (also called DRAK1), is a novel p53 target gene. Cisplatin-mediated induction of STK17A in the EC cell line NT2/D1 was prevented with p53 siRNA. Furthermore, STK17A was induced with cisplatin in HCT116 and MCF10A cells but to a much lesser extent in isogenic p53-suppressed cells. A functional p53 response element that binds endogenous p53 in a cisplatin-dependent manner was identified 5 kb upstream of the first coding exon of STK17A. STK17A is not present in the mouse genome, but the closely related gene STK17B is induced with cisplatin in mouse NIH3T3 cells, although this induction is p53-independent. Interestingly, in human cells containing both STK17A and STK17B, only STK17A is induced with cisplatin. Knockdown of STK17A conferred resistance to cisplatin-induced growth suppression and apoptotic cell death in EC cells. This was associated with the up-regulation of detoxifying and antioxidant genes, including metallothioneins MT1H, MT1M, and MT1X that have previously been implicated in cisplatin resistance. In addition, knockdown of STK17A resulted in decreased cellular reactive oxygen species, whereas STK17A overexpression increased reactive oxygen species. In summary, we have identified STK17A as a novel direct target of p53 and a modulator of cisplatin toxicity and reactive oxygen species in testicular cancer cells.