Kristian Bartnes

Therapeutic vaccination against a murine lymphoma by intratumoral injection of a cationic anticancer peptide

Cationic antimicrobial peptides (CAPs) exhibit promising anticancer activities. In the present study, we have examined the in vivo antitumoral effects of a 9-mer peptide, LTX-302, which is derived from the CAP bovine lactoferricin (LfcinB). A20 B cell lymphomas of BALB/c origin were established by subcutaneous inoculation in syngeneic mice. Intratumoral LTX-302 injection resulted in tumor necrosis and infiltration of inflammatory cells followed by complete regression of the tumors in the majority of the animals. This effect was T cell dependent, since the intervention was inefficient in nude mice. Successfully treated mice were protected against rechallenge with A20 cells, but not against Meth A sarcoma cells. Tumor resistance could be adoptively transferred with spleen cells from LTX-302-treated mice. Resistance was abrogated by depletion of T lymphocytes, or either the CD4+ or CD8+ T cell subsets. Taken together, these data suggest that LTX-302 treatment induced long-term, specific cellular immunity against the A20 lymphoma and that both CD4+ and CD8+ T cells were required. Thus, intratumoral administration of lytic peptide might, in addition to providing local tumor control, confer a novel strategy for therapeutic vaccination against cancer.

Spontaneously formed tumorigenic hybrids of Meth A sarcoma cells and macrophages in vivo.

We have recently demonstrated that malignant cells can hybridize with tissue macrophages in vitro, giving rise to tumorigenic hybrids. We now demonstrate that this can occur spontaneously in vivo as a result of fusion between inoculated Meth A sarcoma cells and host cells, presumably macrophages. Thus, from tumor cell suspensions prepared by collagenase perfusion and density centrifugation, hybrid cells could be isolated that were neoplastic but in contrast to Meth A expressed macrophage markers and had phagocytic capacity. Their morphologic features were intermediate between Meth A and macrophages. By taking advantage of a semiallogeneic experimental system by inoculation of Meth A cells from BALB/c (H‐2 Kd) into (BALB.K × BALB/c) F1 (H‐2k/d), hybrid cells from these tumors could be shown to express MHC antigens of both the Meth A and the host haplotypes. Hybrid cells grew faster than Meth A cells in vivo, indicating acquisition of growth‐promoting properties through heterotypic cell fusion.

Cancer-associated fibroblasts from human NSCLC survive ablative doses of radiation but their invasive capacity is reduced

BackgroundCancer-Associated Fibroblasts (CAFs) are significant components of solid malignancies and play central roles in cancer sustainability, invasion and metastasis. In this study we have investigated the invasive capacity and matrix remodelling properties of human lung CAFs after exposure to ablative doses of ionizing radiation (AIR), equivalent to single fractions delivered by stereotactic ablative radiotherapy (SART) for medically inoperable stage-I/II non-small-cell lung cancers.MethodsCAFs were isolated from lung tumour specimens from 16 donors. Initially, intrinsic radiosensitivity was evaluated by checking viability and extent of DNA-damage response (DDR) at different radiation doses. The migrative and invasive capacities of CAFs were thereafter determined after a sub-lethal single radiation dose of 18 Gy. To ascertain the mechanisms behind the altered invasive capacity of cells, expression of matrix metalloproteinases (MMPs) and their endogenous inhibitors (TIMPs) were measured in the conditioned media several days post-irradiation, along with expression of cell surface integrins and dynamics of focal contacts by vinculin-staining.ResultsExposing CAFs to 1 × 18 Gy resulted in a potent induction of multiple nuclear DDR foci (> 9/cell) with little resolution after 120 h, induced premature cellular senescence and inhibition of the proliferative, migrative and invasive capacity. AIR promoted MMP-3 and inhibited MMP-1 appearance to some extent, but did not affect expression of other major MMPs. Furthermore, surface expression of integrins α2, β1 and α5 was consistently enhanced, and a dramatic augmentation and redistribution of focal contacts was observed.ConclusionsOur data indicate that ablative doses of radiation exert advantageous inhibitory effects on the proliferative, migratory and invasive capacity of lung CAFs. The reduced motility of irradiated CAFs might be a consequence of stabilized focal contacts via integrins.

National trends in lung cancer surgery

OBJECTIVES Trends in lung cancer surgery may reveal potential for improvement and are important for planning by care providers. METHODS Using data from the Cancer Registry of Norway, we analysed the outcomes of lung cancer surgery during the periods of 1994-95, 2000-01 and 2006-07. The Cox regression model was carried out to identify the period effect on survival. RESULTS A total of 2201 patients were operated on. Surgery was centralized from 24 hospitals in the first two periods to 13 hospitals in the last. The resection rates varied from 6 to 31% across the counties. From the first to the last period, the national resection rate increased from 16 to 19% (P(trend) = 0.001), and the 1-year survival rate increased from 73 to 82%. The proportion of resected patients in pathological stage I-II decreased from 87 to 83% (P(trend) = 0.048), the proportion of pneumonectomies from 27 to 15% (P(trend)<0.001), and the rate of mortality within 30 days of the surgery from 4.8 to 3.0% (P(trend) = 0.072). In the first two periods, 31% of these early deaths were caused by complications directly related to the surgical technique, whereas, in the latter period, no deaths were directly related. The only unfavourable trend was the waiting time between the final diagnostic procedure and surgery, which increased from 29 to 40 days throughout the three periods (P < 0.001). Survival (excluding those who died within 30 days) was significantly improved in the last period (risk ratio (RR): 0.72 (P < 0.001)). CONCLUSIONS Despite an increased surgical waiting time, important aspects of lung cancer surgery, including resection rates, have improved in recent years.

Evaluation of a university hospital trauma team activation protocol

BackgroundAdmission with a multidisciplinary trauma team may be vital for the severely injured patient, as this facilitates rapid diagnosis and treatment. On the other hand, patients with minor injuries do not need the trauma team for adequate care. Correct triage is important for optimal resource utilization. The aim of the study was to evaluate our criteria for activating the trauma team, and identify suboptimal criteria that might be changed in the interest of precision.MethodsThe study is an observational, retrospective cohort-study. All patients admitted with the trauma team (n = 382), all severely injured (Injury Severity Score (ISS) >15) (n = 161), and all undergoing an emergency procedure aimed at counteracting compromised airways, respiration or circulation at our hospital (n = 142) during 2006-2007 were included. Data were recorded from the admission records and the electronic patient records. The trauma team activation protocol was evaluated against the occurrence of severe injury and the occurrence of emergency procedures.ResultsA total of 441 patients were included. The overtriage was 71% and undertriage 32% when evaluating against ISS >15 as the standard of reference. When occurrence of emergency procedures was held as the standard of standard of reference, the over- and undertriage was 71% and 21%, respectively. Mechanism of injury-criteria for trauma team activation contributed the most to overtriage. The emergency procedures performed were mostly endotracheal intubation and external fixation of fractures. Less than 3% needed haemostatic laparotomy or thoracotomy. Approximately 2/3 of the overtriage represented isolated head or cervical spine injuries, and/or interhospital transfers.ConclusionsThe over- and undertriage of our protocol are both too high. To decrease overtriage we suggest omissions and modifications of some of the criteria. To decrease undertriage, transferred patients and patients with head injuries should be more thoroughly assessed against the trauma team activation criteria.

Spontaneously formed tumorigenic hybrids of Meth A sarcoma and macrophages grow faster and are better vascularized than the parental tumor.

Macrophages and Meth A sarcoma cells spontaneously fuse and give rise to tumorigenic hybrid cell lines with a mixed phenotype. We report here that the hybrid tumors grow faster and have a strikingly better developed vasculature than the parent sarcoma. Thus, electron microscopy and immunohistochemical analysis revealed that in the most active areas of neovascularization, the tumors that emerged from inocula of monoclonal hybrid cell populations had a microvessel density nearly twice that of Meth A tumors after 1 week of growth. Moreover, the proportion of vessels associated with pericytes, detected by staining for smooth muscle α‐actin, was 3 times higher in the hybrid tumors, attesting to the more advanced differentiation of their vasculature. The collagenous stroma component was also more extensive in the hybrid tumors. Concentration of the angiogenic proteins vascular endothelial growth factor (VEGF) and transforming growth factor‐β (TGF‐β) were significantly higher in supernatants of hybrid cell cultures compared with Meth A cultures. These observations indicate that the growth advantage of the hybrid tumors over the parental sarcoma is due to a higher angiogenic capacity. Because the malignant features of many tumors correlate with angiogenesis and because macrophages are known to be major producers of angiogenic factors, our data open the possibility that the intense neovascularization of highly aggressive cancers in some cases reflects the acquisition of macrophage traits by heterotypic cell fusion.

N-terminal elongation of a peptide determinant beyond the first primary anchor improves binding to H-2 I-Ad and HLA-DR1 by backbone-dependent and aromatic side chain-dependent interactions, respectively.

The IgG2ab heavy chain allopeptide determinant γ2ab 436 – 451 (Kabat numbering) presented by the major histocompatibility complex (MHC) class II molecule I‐Ad is recognized by T cells which cross‐react with a corneal self antigen and with the UL6 protein of the herpes simplex virus which induce autoimmune keratitis, and is the target of Th1 clones that suppress IgG2ab production in vivo. In the γ2ab peptide/I‐Ad complex, tyrosine438 is the first primary anchor (P1) and residues 440 – 445 encompass the T cell receptor contact residues. Amino‐terminal elongation of γ2ab 437– 451 by a single residue (P‐2) augmented the I‐Ad binding capacity 10‐fold and the antigenicity 55 –195‐fold. This was a function of the peptide main chain, since non‐conservative substitutions were accepted. The γ2ab peptide also bound HLA‐DR1, and amino‐terminal extension by a single aromatic amino acid at P‐3 augmented binding 15‐fold. The interaction between HLA‐DR1 and P‐3 specifically required an aromatic peptide side chain, and computer simulations indicated that the aromatic ring at P‐3 engaged conserved HLA‐DR1 phenylalanine residues at the edge of the peptide binding groove. Thus, these data demonstrate that residues amino terminal to P1 may substantially increase peptide affinity for MHC class II by main chain‐dependent as well as side chain‐dependent interactions, and imply that the HLA‐DR1 motif should be extended to include an aromatic amino acid at P‐3.

Extent of Preoperative False Lumen Thrombosis Does Not Influence Long-Term Survival in Patients With Acute Type A Aortic Dissection

Background Partial thrombosis of the false lumen has been related to aortic growth, reoperations, and death in the chronic phase of type B and repaired type A aortic dissections. The impact of preoperative false lumen thrombosis has not been studied previously. We used data from a contemporary, multinational database on aortic dissections to evaluate whether different degrees of preoperative false lumen thrombosis influenced long‐term prognosis. Methods and Results We examined the records of 522 patients with surgically treated acute type A aortic dissections who survived to discharge between 1996 and 2011. At the preoperative imaging, 414 (79.3%) patients had patent false lumens, 84 (16.1%) had partial thrombosis of the false lumen, and 24 (4.6%) had complete thrombosis of the false lumen. The annual median (interquartile range) aortic growth rates were 0.5 (−0.3 to 2.0) mm in the aortic arch, 2.0 (0.2 to 4.0) mm in the descending thoracic aorta, and similar regardless of the degree of false lumen thrombosis. The overall 5‐year survival rate was 84.7%, and it was not influenced by false lumen thrombosis (P=0.86 by the log‐rank test). Independent predictors of long‐term mortality were age >70 years (hazard ratio [HR], 2.34; 95% confidence interval [CI], 1.20 to 4.56, P=0.012) and postoperative cerebrovascular accident, coma, and/or renal failure (HR, 2.62; 95% CI, 1.40 to 4.92, P=0.003). Conclusions Patients with acute type A aortic dissection who survive to discharge have a favorable prognosis. Preoperative false lumen thrombosis does not influence long‐term mortality, reintervention rates, or aortic growth.

Spontaneous hybridization of macrophages and Meth A sarcoma cells

We present evidence of hybridization between Meth A sarcoma cells and syngeneic as well as semigeneic peritoneal macrophages. The resultant hybrids are characterized by morphology, membrane markers, ploidy, chromosomal content and functional features. Briefly, after a few days of coculture, cells appeared with morphology intermediate between the 2 original cell types. Typical macrophage surface molecules appeared in the hybrids. Meth A cells were labeled with red fluorescence and macrophages with green fluorescence. After 4 days in vitro, hybrids with yellow fluorescence appeared. Macrophages from BALB.K mice (H‐2 Kk) were cocultivated with Meth A cells from BALB/c mice (H‐2 Kd). The semigeneic hybrids displayed both specificities, as demonstrated by flow cytometry. The hybrids appeared moderately phagocytic, less so than the macrophages and markedly more so than the essentially nonphagocytic Meth A cells. The hybrids had a mean number of 76 chromosomes, as opposed to 53 in the Meth A cells and 40 in the macrophages. The macrophage DNA index was set at 1; Meth A cells were found to have an index of 1.6 in G1 phase, and the hybrids had a 2.6 index. The hybrids grew more slowly in vitro than Meth A cells, but grew faster in vivo.

Lung cancer treatment is influenced by income, education, age and place of residence in a country with universal health coverage.

Selection of lung cancer treatment should be based on tumour characteristics, physiological reserves and preferences of the patient. Our aims were to identify and quantify other factors associated with treatment received. Lung cancer patient data from 2002 to 2011 were obtained from the national population‐based Cancer Registry of Norway, Statistics Norway and the Norwegian Patient Register. Multivariable logistic regression examined whether year of diagnosis, age, sex, education, income, health trust, smoking status, extent of disease, histology and comorbidities were associated with choice of treatment; surgery or radical or palliative radiotherapy, within 1 year of diagnosis. Among the 24,324 lung cancer patients identified, the resection rate remained constant while the proportion of radical radiotherapy administered increased from 8.6 to 14.1%. Older patients, those with lower household incomes and certain health trusts were less likely to receive any treatment. Lower education and the male gender were identified as negative predictors for receiving surgery. Smoking history was positively associated with both radical and palliative radiotherapy, while comorbidity and symptoms were independently associated with receiving surgery and palliative radiotherapy. Although Norway is a highly egalitarian country with a free, universal healthcare system, this study indicates that surgery and radical and palliative radiotherapy were under‐used among the elderly, those with a lower socioeconomic status and those living in certain health trusts.