Anti-proliferative but not anti-angiogenic tyrosine kinase inhibitors enrich for cancer stem cells in soft tissue sarcoma.

BackgroundIncreasing studies implicate cancer stem cells (CSCs) as the source of resistance and relapse following conventional cytotoxic therapies. Few studies have examined the response of CSCs to targeted therapies, such as tyrosine kinase inhibitors (TKIs). We hypothesized that TKIs would have differential effects on CSC populations depending on their mechanism of action (anti-proliferative vs. anti-angiogenic).MethodsWe exposed human sarcoma cell lines to sorafenib, regorafenib, and pazopanib and assessed cell viability and expression of CSC markers (ALDH, CD24, CD44, and CD133). We evaluated survival and CSC phenotype in mice harboring sarcoma metastases after TKI therapy. We exposed dissociated primary sarcoma tumors to sorafenib, regorafenib, and pazopanib, and we used tissue microarray (TMA) and primary sarcoma samples to evaluate the frequency and intensity of CSC markers after neoadjuvant therapy with sorafenib and pazopanib. Parametric and non-parametric statistical analyses were performed as appropriate.ResultsAfter functionally validating the CSC phenotype of ALDHbright sarcoma cells, we observed that sorafenib and regorafenib were cytotoxic to sarcoma cell lines (P < 0.05), with a corresponding 1.4 - 2.8 fold increase in ALDHbright cells from baseline (P < 0.05). In contrast, we observed negligible effects on viability and CSC sub-populations with pazopanib. At low doses, there was progressive CSC enrichment in vitro after longer term exposure to sorafenib although the anti-proliferative effects were attenuated. In vivo, sorafenib improved median survival by 11 days (P < 0.05), but enriched ALDHbright cells 2.5 - 2.8 fold (P < 0.05). Analysis of primary human sarcoma samples revealed direct cytotoxicity following exposure to sorafenib and regorafenib with a corresponding increase in ALDHbright cells (P < 0.05). Again, negligible effects from pazopanib were observed. TMA analysis of archived specimens from sarcoma patients treated with sorafenib demonstrated significant enrichment for ALDHbright cells in the post-treatment resection specimen (P < 0.05), whereas clinical specimens obtained longitudinally from a patient treated with pazopanib showed no enrichment for ALDHbright cells (P > 0.05).ConclusionsAnti-proliferative TKIs appear to enrich for sarcoma CSCs while anti-angiogenic TKIs do not. The rational selection of targeted therapies for sarcoma patients may benefit from an awareness of the differential impact of TKIs on CSC populations

Advances in modeling the immune microenvironment of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the US. CRC frequently metastasizes to the liver and these patients have a particularly poor prognosis. The infiltration of immune cells into CRC tumors and liver metastases accurately predicts disease progression and patient survival. Despite the evident influence of immune cells in the CRC tumor microenvironment (TME), efforts to identify immunotherapies for CRC patients have been limited. Here, we argue that preclinical model systems that recapitulate key features of the tumor microenvironment-including tumor, stromal, and immune cells; the extracellular matrix; and the vasculature-are crucial for studies of immunity in the CRC TME and the utility of immunotherapies for CRC patients. We briefly review the discoveries, advantages, and disadvantages of curren

Anti-proliferative but not anti-angiogenic tyrosine kinase inhibitors enrich for cancer stem cells in soft tissue sarcoma

The templated zeolite-analogue GaPO-34 (CHA structure type) crystallises from a gel precursor Ga2O3:2H3PO4:1HF:1.7SDA:70H2O (where SDA = structure directing agent), treated hydrothermally for 24 hours at 170 °C using either pyridine or 1-methylimizadole as SDA and one of either poorly crystalline ε-Ga2O3 or γ-Ga2O3 as gallium precursor. If the same gels are stirred for periods shorter than 2 hours but treated under identical hydrothermal conditions, then a second phase crystallises, free of GaPO-34. If β-Ga2O3 is used as a reagent only the second phase is found to crystallise, irrespective of gel aging time. The competing phase, which we denote GaPO-34A, has been structurally characterised using synchrotron powder X-ray diffraction for the pyridine material, GaPO-34A(pyr), and using single-crystal X-ray diffraction for the 1-methylimiazole material, GaPO-34A(mim). The structure of GaPO-34A(pyr), P1 @#x0305;, a = 10.22682(6) Å, b = 12.09585(7) Å, c = 13.86713(8) Å, α = 104.6531(4) °, β = 100.8111(6) °, γ = 102.5228(6) °, contains 7 unique gallium sites and 6 phosphorus sites, with empirical formula [Ga7P6O24(OH)2F3(H2O)2].2(C5NH6). GaPO-34A(mim) is isostructural but is modelled as a half volume unit cell, P1 @#x0305;, a = 5.0991(2) Å, b = 12.0631(6) Å, c = 13.8405(9) Å, α = 104.626(5) °, β = 100.346(5) °, γ = 101.936(4) °, with a gallium and a bridging fluoride partially occupied and two partially occupied SDA sites. Solid-state 31P and 71Ga NMR spectroscopy confirms the structural complexity of GaPO-34A with signals resulting from overlapping lineshapes from multiple Ga and P sites, while 1H and 13C solid-state NMR spectra confirm the presence of the protonated SDA and provide evidence for disorder in the SDA. The protonated SDA is located in 14-ring one-dimensional channels with hydrogen bonding deduced from the SDA nitrogens to framework oxygen distances. Upon thermal treatment to investigate SDA removal, structure collapse occurs, which may be due the large number of bridging hydroxides and fluorides in the as-made material, and the unequal amounts of gallium and phosphorus present

The scene of the crime: inventing the serial killer

This article examines the meanings of the crime scene in serial killings, and the tensions between the real and the imagined in the circulation of those meanings. Starting with the Whitechapel Murders of 1888 it argues that they, as well as forming an origin for the construction of the identity of 'the serial killer', initiate certain ideas about the relationship of subjects to spaces and the existence of the self in the modern urban landscape. It suggests that these ideas come to play an integral part in the contemporary discourse of serial killing, both in the popular imagination and in professional analysis. Examining the Whitechapel Murders, more recent cases and modern profiling techniques, it argues that popular and professional representations of crime scenes reveal more of social anxieties about the nature of the public and the private than they do about serial killers. It suggests that 'the serial killer' is not a coherent type, but an invention produced from the confusions of persons and places. Copyright 2006 SAGE Publications. All rights reserved. Not for commercial use or unauthorized distribution

Enhanced targeting of stem-like solid tumor cells with radiation and natural killer cells

Natural killer (NK) cells are innate lymphocytes postulated to mediate resistance against primary haematopoietic but not solid tumor malignancies. Cancer stem cells (CSCs) are a small subset of malignant cells with stem-like properties which are resistant to chemo- and radiotherapies and are able to repopulate a tumor after cytoreductive treatments. We observed increased frequencies of stem-like tumor cells after irradiation, with increased expression of stress ligands on surviving stem-like cells. Ex vivo NK cells activated by low dose IL2 in vitro and IL15 in vivo displayed an increased ability to target solid tumor stem-like cells both in vitro and in vivo after irradiation. Mechanistically, both upregulation of stress-related ligands on the stem-like cells as well as debulking of non-stem populations contributed to these effects as determined by data from cell lines, primary tumor samples, and most relevant patient derived specimens. In addition, pretreatment of tumor-bearing mice with local radiation prior to NK transfer resulted in significantly longer survival indicating that radiation therapy in conjunction with NK cell adoptive immunotherapy targeting stem-like cancer cells may offer a promising novel radio-immunotherapy approach in the clinic

Advances in Modeling the Immune Microenvironment of Colorectal Cancer.

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the US. CRC frequently metastasizes to the liver and these patients have a particularly poor prognosis. The infiltration of immune cells into CRC tumors and liver metastases accurately predicts disease progression and patient survival. Despite the evident influence of immune cells in the CRC tumor microenvironment (TME), efforts to identify immunotherapies for CRC patients have been limited. Here, we argue that preclinical model systems that recapitulate key features of the tumor microenvironment-including tumor, stromal, and immune cells; the extracellular matrix; and the vasculature-are crucial for studies of immunity in the CRC TME and the utility of immunotherapies for CRC patients. We briefly review the discoveries, advantages, and disadvantages of current in vitro and in vivo model systems, including 2D cell culture models, 3D culture systems, murine models, and organ-on-a-chip technologies

Enhanced targeting of stem-like solid tumor cells with radiation and natural killer cells

Natural killer (NK) cells are innate lymphocytes postulated to mediate resistance against primary haematopoietic but not solid tumor malignancies. Cancer stem cells (CSCs) are a small subset of malignant cells with stem-like properties which are resistant to chemo- and radiotherapies and are able to repopulate a tumor after cytoreductive treatments. We observed increased frequencies of stem-like tumor cells after irradiation, with increased expression of stress ligands on surviving stem-like cells. Ex vivo NK cells activated by low dose IL2 in vitro and IL15 in vivo displayed an increased ability to target solid tumor stem-like cells both in vitro and in vivo after irradiation. Mechanistically, both upregulation of stress-related ligands on the stem-like cells as well as debulking of non-stem populations contributed to these effects as determined by data from cell lines, primary tumor samples, and most relevant patient derived specimens. In addition, pretreatment of tumor-bearing mice with local radiation prior to NK transfer resulted in significantly longer survival indicating that radiation therapy in conjunction with NK cell adoptive immunotherapy targeting stem-like cancer cells may offer a promising novel radio-immunotherapy approach in the clinic

Missing a “Missing Self” Mechanism: Modeling and Detection of Ly49 Expression in Canine NK Cells

NK cells are a key focus in immuno-oncology, based on their ability to eliminate malignant cells without prior sensitization. Dogs are valuable models for translational immunotherapy studies, especially for NK cells, where critical species differences exist between mice and humans. Given that the mechanism for recognition of "self" by canine NK cells is currently unknown, we sought to evaluate expression of Ly49 in canine NK cells using in silico and high-throughput techniques. We interrogated the identified polymorphism/mutation in canine Ly49 and assessed the potential impact on structure using computational modeling of three-dimensional protein structure and protein-protein docking of canine Ly49 with MHC class I (MHC-I). Bulk and single-cell RNA-sequencing analysis was performed to detect gene expression of Ly49/KLRA1 in resting and activated NK cells. Tertiary protein structure demonstrated significant structural similarity to the known murine system. Molecular docking of canine Ly49 with MHC-I was favorable, converging at a single low-energy conformation. RNA sequencing revealed expression of Ly49/KLRA1 in both resting and activated NK cells and demonstrated almost exclusive expression of the gene in the NK cluster at the single-cell level. Despite prior reports of a mutated, nonfunctional canine Ly49, our data support that the protein product is predicted to bind to MHC-I in a comparable conformation to the murine system and is expressed in canine NK cells with upregulation following activation. Taken together, these data suggest that Ly49 is capable of recognizing MHC-I and therefore regulating NK cell function in dogs

Surgical decision-making in advanced-stage non–small cell lung cancer is influenced by more than just guidelines

ObjectiveThis qualitative study sought to uncover factors that influence decisions to offer curative-intent surgery for patients with advanced-stage (stage IIIB/IV) non-small cell lung cancer.MethodsA trained interviewer conducted open-ended, semistructured telephone interviews with cardiothoracic surgeons in the United States. Participants were recruited from the Thoracic Surgery Outcomes Research Network, with subsequent diversification through snowball sampling. Four hypothetical clinical scenarios were presented, each demonstrating varying levels of ambiguity with respect to international guideline recommendations. Interviews continued until thematic saturation was reached. Interview transcripts were coded using inductive reasoning and conventional content analysis.ResultsOf the 27 participants, most had been in practice for ≤20 years (n = 23) and were in academic practice (n = 18). When considering nonguideline-concordant surgeries, participants were aware of relevant guidelines but acknowledged their limitations for unique scenarios. Surgeons perceived that a common barrier to offering surgery is incomplete nonsurgeon physician understanding of surgical capabilities or expected morbidity; and that improved education is necessary to correct these misperceptions. Surgeons expressed concern that undertaking a controversial resection for an individual patient could fracture trust built in long-term professional relationships. Surgeons may face pressure from patients to operate despite a low expectation of clinical benefit, leading to emotional turmoil for the patient and surgeon.ConclusionsThis qualitative study generates the hypothesis that the scope of current guidelines, availability of clinical trial protocols, perceived surgical knowledge among nonsurgeon colleagues, interprofessional relationships, and emotional pressure all influence a surgeon's willingness to offer curative-intent surgery for patients with advanced-stage non-small cell lung cancer