NOTCH1 Signaling Promotes Human T-Cell Acute Lymphoblastic Leukemia Initiating Cell Regeneration in Supportive Niches

Leukemia initiating cells (LIC) contribute to therapeutic resistance through acquisition of mutations in signaling pathways, such as NOTCH1, that promote self-renewal and survival within supportive niches. Activating mutations in NOTCH1 occur commonly in T cell acute lymphoblastic leukemia (T-ALL) and have been implicated in therapeutic resistance. However, the cell type and context specific consequences of NOTCH1 activation, its role in human LIC regeneration, and sensitivity to NOTCH1 inhibition in hematopoietic microenvironments had not been elucidated.We established humanized bioluminescent T-ALL LIC mouse models transplanted with pediatric T-ALL samples that were sequenced for NOTCH1 and other common T-ALL mutations. In this study, CD34(+) cells from NOTCH1(Mutated) T-ALL samples had higher leukemic engraftment and serial transplantation capacity than NOTCH1(Wild-type) CD34(+) cells in hematopoietic niches, suggesting that self-renewing LIC were enriched within the NOTCH1(Mutated) CD34(+) fraction. Humanized NOTCH1 monoclonal antibody treatment reduced LIC survival and self-renewal in NOTCH1(Mutated) T-ALL LIC-engrafted mice and resulted in depletion of CD34(+)CD2(+)CD7(+) cells that harbor serial transplantation capacity.These results reveal a functional hierarchy within the LIC population based on NOTCH1 activation, which renders LIC susceptible to targeted NOTCH1 inhibition and highlights the utility of NOTCH1 antibody targeting as a key component of malignant stem cell eradication strategies

Evaluating predictive factors for toxicities experienced by head & neck cancer patients undergoing radiotherapy.

PurposeThe purpose of this study was to evaluate if HPV status serves as an independent predictor of early and late dysphagia outcomes when considered alongside standard patient characteristics and dose metrics for head and neck cancer patients treated with radiotherapy.Methods and materialsThe age, sex, smoking history, cancer type (oropharyngeal vs non-oropharyngeal), HPV status, and early and late dysphagia outcomes were obtained for 99 retrospective head and neck cancer patients treated at our clinic with radiotherapy. Additionally for each patient, the mean radiation dose to the pharynx, superior/middle/inferior pharyngeal constrictor muscles, and cricopharyngeus was calculated. The predictive power of these clinical characteristics and radiation metrics was evaluated using chi-square tests for categorical variables and t-tests for continuous variables. Then multi-variate logistic models were built for each outcome using a single dose metric at a time, and either HPV status, cancer type, or both. Multi-variate models were built using both top-down and bottom-up technique to establish the most predictive independent covariates.ResultsIn the univariate analysis for early dysphagia, cancer type (p = 0.04) and four dose metrics (p ≤ 0.02) were significantly associated with outcome, while for late dysphagia, only cancer type (p = 0.04) was associated with outcome. In the multivariate analysis for early dysphagia, cancer type, smoking history, and mean dose to the five structures were consistently selected as covariates. For late dysphagia, either HPV status or cancer type was selected in each model and the mean dose to the cricopharyngeus was selected in one model.ConclusionWhile HPV is a known contributing factor for tumor prognosis in oropharyngeal cancers, its role in normal tissue toxicities for head and neck cancers has not previously been evaluated. Our results indicate having an oropharyngeal cancer may increase a patient's risk of high-grade early and late dysphagia while HPV status was seldom selected

Gene alterations as predictors of radiation-induced toxicity in head and neck squamous cell carcinoma.

BackgroundOptimizing the therapeutic ratio for radiation therapy (RT) in head and neck squamous cell carcinoma (HNSCC) is uniquely challenging owing to high rates of early and late toxicity involving nearby organs at risk. These toxicities have a profound impact on treatment compliance and quality of life. Emerging evidence suggests that RT dose alone cannot fully account for the variable severity of RT-related adverse events (rtAEs) observed in HNSCC patients. Next-generation sequencing has become an increasingly valuable tool with widespread use in the oncology field and is being robustly explored for predicting rtAEs beyond dosimetric data.MethodsPatients who had Foundation Medicine sequencing data and received RT for primary or locally recurrent HNSCC were selected for this study. Early and late toxicity data were collected and reported based on Common Terminology Criteria for Adverse Events version 5.0. Dosimetric parameters were collected for pertinent structures.ResultsA total of HNSCC 37 patients were analyzed in this study. Genetic alterations in BRCA2, ERBB3, NOTCH1 and CCND1 were all associated with higher mean grade of toxicity with BRCA2 alteration implicated in all toxicity parameters evaluated including mucositis, early dysphagia, xerostomia and to a lesser extent, late dysphagia. Interestingly, patients who exhibited alterations in both BRCA2 and ERBB3 experienced a twofold or greater increase in early dysphagia, early xerostomia and late dysphagia compared to ERBB3 alteration alone. Furthermore, several gene alterations were associated with improved toxicity outcomes. Within an RT supersensitive patient subset, alterations were found in TNFAIP3, HNF1A, SPTA1 and CASP8. All of these alterations were not found in the RT insensitive patient subset. We found 17 gene alterations in the RT insensitive patient subset that were not found in the RT supersensitive patient subset.ConclusionDespite consistent RT dosimetric parameters, patients with HNSCC experience heterogeneous patterns of rtAEs. Identifying factors associated with toxicity outcomes offers a new avenue for personalized precision RT therapy and prophylactic management. Here, next-generation sequencing in a population of HNSCC patients correlates several genetic alterations with severity of rtAEs. Further analysis is urgently needed to identify genetic patterns associated with rtAEs in order to reduce harmful outcomes in this challenging population

Germline genetic biomarkers to stratify patients for personalized radiation treatment.

BackgroundPrecision medicine incorporating genetic profiling is becoming a standard of care in medical oncology. However, in the field of radiation oncology there is limited use of genetic profiling and the impact of germline genetic biomarkers on radiosensitivity, radioresistance, or patient outcomes after radiation therapy is poorly understood. In HNSCC, the toxicity associated with treatment can cause delays or early cessation which has been associated with worse outcomes. Identifying potential biomarkers which can help predict toxicity, as well as response to treatment, is of significant interest.MethodsPatients with HNSCC who received RT and underwent next generation sequencing of somatic tumor samples, transcriptome RNA-seq with matched normal tissue samples were included. Patients were then grouped by propensity towards increased late vs. early toxicity (Group A) and those without (Group B), assessed by CTCAE v5.0. The groups were then analyzed for association of specific germline variants with toxicity and clinical outcomes.ResultsIn this study we analyzed 37 patients for correlation between germline variants and toxicity. We observed that TSC2, HLA-A, TET2, GEN1, NCOR2 and other germline variants were significantly associated with long term toxicities. 34 HNSCC patients treated with curative intent were evaluated for clinical outcomes. Group A had significantly improved overall survival as well as improved rates of locoregional recurrence and metastatic disease. Specific variants associated with improved clinical outcomes included TSC2, FANCD2, and PPP1R15A, while the HLA-A and GEN1 variants were not correlated with survival or recurrence. A group of five HLA-DMA/HLA-DMB variants was only found in Group B and was associated with a higher risk of locoregional recurrence.ConclusionsThis study indicates that germline genetic biomarkers may have utility in predicting toxicity and outcomes after radiation therapy and deserve further investigation in precision radiation medicine approaches

Differential regulation of TNFα and IL-6 expression contributes to immune evasion in prostate cancer

BackgroundThe role of the inflammatory milieu in prostate cancer progression is not well understood. Differences in inflammatory signaling between localized and metastatic disease may point to opportunities for early intervention.MethodsWe modeled PCa disease progression by analyzing RNA-seq of localized vs. metastatic patient samples, followed by CIBERSORTx to assess their immune cell populations. The VHA CDW registry of PCa patients was analyzed for anti-TNF clinical outcomes.ResultsWe observed statistically significant opposing patterns of IL-6 and TNFα expression between localized and metastatic disease. IL-6 was robustly expressed in localized disease and downregulated in metastatic disease. The reverse was observed with TNFα expression. Metastatic disease was also characterized by downregulation of adhesion molecule E-selectin, matrix metalloproteinase ADAMTS-4 and a shift to M2 macrophages whereas localized disease demonstrated a preponderance of M1 macrophages. Treatment with anti-TNF agents was associated with earlier stage disease at diagnosis.ConclusionsOur data points to clearly different inflammatory contexts between localized and metastatic prostate cancer. Primary localized disease demonstrates local inflammation and adaptive immunity, whereas metastases are characterized by immune cold microenvironments and a shift towards resolution of inflammation and tissue repair. Therapies that interfere with these inflammatory networks may offer opportunities for early intervention in monotherapy or in combination with immunotherapies and anti-angiogenic approaches

Leukemia regenerative capacity of the CD45⁺CD34⁺CD2⁺CD7⁺ population.

<p>(A) Representative photographs of hematopoietic organs following intrahepatic transplantation of 1 500 FACS purified CD34⁺CD2⁺CD7⁺Lin⁻ cells from a NOTCH1^Mutated T-ALL (Patient 05) sample demonstrates serial transplantation potential of this refined LIC population, as shown by the presence of an enlarged thymus, spleen and pale marrows over several transplantation generations. (B, C) FACS analysis of the tertiary (3°) transplant recipients of 30000 CD34⁺CD2⁺CD7⁺Lin⁻ cells sorted from a NOTCH1^Mutated T-ALL (Patient 11) revealed the persistence of an expanded human CD45⁺CD34⁺CD2⁺ (including CD7⁺ and CD7⁻) population in the transplanted mouse hematopoietic organs (bone marrow, spleen, thymus and liver).</p

hN1 mAb treatment inhibits <i>NOTCH1^Mutated</i> LIC burden.

<p>(A) Comparative FACS analysis of human CD34⁺CD45⁺ cells and CD34⁺CD2⁺ leukemic burden in the bone marrows from NOTCH1^Mutated LIC (Patient 11) engrafted mice following treatment with control mAb (left panel) or hN1 mAb (right panel). (B) FACS analysis of human CD34⁺ and NOTCH1⁺ cell survival in the mouse spleens following control mAb (n = 9) or hN1 mAb treatment (n = 9) of NOTCH1^Mutated LIC (Patients 05, 08, 11) engrafted mice (upper panel). Representative FACS plots show the reduction in both CD34⁺ and NOTCH1⁺ cell populations. (C) Representative FACS analysis demonstrating engraftment of CD34⁺CD45⁺ cells in the bone marrows of secondary (2°) transplant recipients following transplantation of control mAb (left panel) or hN1 mAb (right panel) treated bone marrow (Patient 11). (D) Graph of percent human T-ALL total CD45⁺ (blue) and CD34⁺CD45⁺ (red) cells in the bone marrows of 2° transplant recipients of control mAb (n = 6) and hN1 mAb (n = 6) treated NOTCH1-driven LIC (Patients 02, 11) (error bars ± SEM; P = 0.16, and P = 0.086, respectively, by Student’s t-test). All results reflect data collected from two independent experiments.</p