Întegrins, matrix metalloproteases (MMPs), and the cytokine TGF-β have each been implicated in homeostatic cell behaviors such as cell growth and matrix remodeling. TGF-β exists mainly in a latent state, and a major point of homeostatic control is the activation of TGF-β. Because the latent domain of TGF-β1 possesses an integrin binding motif (RGD), integrins have the potential to sequester latent TGF-β (SLC) to the cell surface where TGF-β activation could be locally controlled. Here, we show that SLC binds to αvβ8, an integrin expressed by normal epithelial and neuronal cells in vivo. This binding results in the membrane type 1 (MT1)-MMP–dependent release of active TGF-β, which leads to autocrine and paracrine effects on cell growth and matrix production. These data elucidate a novel mechanism of cellular homeostasis achieved through the coordination of the activities of members of three major gene families involved in cell–matrix interactions.

Like many tumors, malignant mesothelioma exhibits significant chemoresistance and resistance to apoptosis in vivo that is not seen in current in vitro models. To study the mechanisms of this multicellular resistance, biologically relevant in vitro models are necessary. Therefore, we characterized and tested human mesothelioma tissue grown in vitro as tumor fragment spheroids. After 5-10 d in culture, fragments from each of 15 human mesothelioma tumors rounded into spheroids. The tumor fragment spheroids maintained multiple characteristics of the original tumors for up to 3 mo including the presence of viable mesothelioma cells, macrophages, and a collagenrich stroma. In 14-d-old spheroids, mesothelioma cells showed the same proliferation rate and expression of a death receptor, DR5, as in the original tumor. To determine responses to treatment, we treated tumor fragment spheroids grown from three separate tumors with agents, TNF-related apoptosis-inducing ligand (TRAIL) plus cycloheximide, that induced near total apoptosis in three human mesothelioma cell lines (M28, REN, MS-1) grown as monolayers (94 Ϯ 6% apoptosis; mean Ϯ SEM). Compared with mesothelioma cells in monolayers, mesothelioma cells in the spheroids were resistant to TRAIL plus cycloheximide (32 Ϯ 4% apoptosis; mean Ϯ SEM). Apoptotic resistance of mesothelioma cells was significantly reduced by inhibiting either the PI3K/Akt pathway with LY294002 (47 Ϯ 6% apoptosis) or the mTOR pathway with rapamycin (50 Ϯ 17% apoptosis). We conclude that human mesothelioma can be maintained in vitro in a biologically relevant model that exhibits apoptotic resistance, thereby permitting study of its tumor biology and of novel approaches to therapy. Keywords: collagen; death receptor DR5; mTOR; multicellular resistance; PI3K/Akt survival pathway; TNF-related apoptosis-inducing ligand (TRAIL); tumor-associated macrophage; tumor fragment spheroid Resistance to apoptosis, or programmed cell death, is now considered to be a critical step in the generation and maintenance of cancer (1). Resistance to apoptosis may underlie the resistance of tumors to chemotherapy and radiotherapy (2). Mechanisms of resistance have been identified on a cellular level, for example via P-glycoprotein efflux pumps, DNA repair mechanisms, or from expression of anti-apoptotic proteins such as Bcl-2 (3). Additional mechanisms of resistance are now recognized to involve stimuli from the cell's external environment, termed multicellular resistance (3). These multicellular resistance mechanisms have been attributed to cell-cell contacts, cell-matrix contacts, and the three-dimensional shape found in tissues but (Received in original form November 14, 2004 and in final form July 30, 2005) *These authors contributed equally to this work. Two types of in vitro models used to study the complex resistance found in tumors are multicellular spheroids and tumor fragment spheroids (5, 6). In the first, cells are allowed to grow into three-dimensional structures called multicellular spheroids (5). In thes...

Transforming growth factor (TGF)-beta is a potent multifunctional cytokine that is an essential regulator of epithelial proliferation. Because TGF-beta is expressed almost entirely in a latent state in vivo, a major source of regulation of TGF-beta function is its activation. A subset of integrins, alphavbeta8 and alphavbeta6, which are expressed in the human airway, has recently been shown to activate latent TGF-beta in vitro, suggesting a regulatory role for integrins in TGF-beta function in vivo. Here we have developed a novel, biologically relevant experimental model of human airway epithelium using intact human bronchial tissue. We have used this model to determine the function of integrin-mediated activation of TGF-beta in the airway. In human bronchial fragments cultured in vitro, authentic epithelial-stromal interactions were maintained and integrin and TGF-beta expression profiles correlated with profiles found in normal lung. In addition, in this model, we found that either the integrin alphavbeta8 or TGF-beta could inhibit airway epithelial cell proliferation. Furthermore, we found that one mechanism of integrin-alphavbeta8-dependent inhibition of cell proliferation was through activation of TGF-beta because anti-beta8 antibody blocked the majority (76%) of active TGF-beta released from bronchial fragments. These data provide compelling evidence for a functional role for integrin-mediated activation of TGF-beta in control of human airway epithelial proliferation in vivo.

Exon 20 mutations seem to confer insensitivity to TKI treatment.

There have been notable changes in incidence patterns and a remarkable improvement in survival for lung cancer over the last 17 years, most markedly for patients without distant metastases at the time of diagnosis. Hopefully, survival will improve even more when immunotherapy is implemented.

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.According to Norwegian guidelines, lung cancer treatment should be based on extent of disease (EOD), tumor histology, comorbidities, performance status and preferences of the patient.1 Surgical resection is considered a prerequisite for the cure of lung cancer, but a benefit has only been shown for patients with localized disease, that is, disease that does not extend beyond the intrapulmonary or hilar lymph nodes.Stereotactic radiotherapy has recently become an alternative for selected patients. 2,3 If a patient is deemed ineligible for surgical treatment due to EOD or significant comorbidities, radiotherapy and/or chemotherapy can be offered. For patients with mediastinal lymph node metastasis, this combination is offered with curative intent, while for patients whose tumours have spread beyond the lung and mediastinum, in the majority of patients, palliative radiotherapy and/ or chemotherapy are offered for symptom relief, to slow disease progression and improve medium term survival. Likelihood of both receiving surgical treatment and radiotherapy as treatment for lung cancer has previously been shown to be affected by factors not mentioned in guidelines. A number of studies have found that socioeconomic status (SES) and/or place of residence may influence the likelihood of receiving surgical treatment. [4][5][6][7][8] However, the influence of SES on radiotherapy remains inconclusive. 4,[9][10][11] Previous studies have been unable to examine the association between lung canc...

We examine changes in survival and patient-, tumour-and treatment-related factors among resected and nonresected lung cancer patients, and identify subgroups with the largest and smallest survival improvements.National population-based data from the Cancer Registry of Norway, Statistics Norway and the Norwegian Patient Register were linked for lung cancer patients diagnosed during 1997-2011. The 1-and 5-year relative survival were estimated, and Cox proportional hazard regression, adjusted for selected patient characteristics, was used to assess prognostic factors for survival in lung cancer patients overall and stratified by resection status.We identified 34 157 patients with lung cancer. The proportion of histological diagnoses accompanied by molecular genetics testing increased from 0% to 26%, while those accompanied by immunohistochemistry increased from 8% to 26%. The 1-year relative survival among nonresected and resected patients increased from 21.7% to 34.2% and 75.4% to 91.5%, respectively. The improved survival remained significant after adjustment for age, sex, stage and histology. The largest improvements in survival occurred among resected and adenocarcinoma patients, while patients ⩾80 years experienced the smallest increase.Lung cancer survival has increased considerably in Norway. The explanation is probably multifactorial, including improved attitude towards diagnostic work-up and treatment, and more accurate diagnostic testing that allows for improved selection for resection and improved treatment options. @ERSpublications Lung cancer survival in Norway has improved due to improved attention towards diagnostic work-up and treatment http://ow.ly/S5L4j

Biopsy material from 17 human non-small-cell lung carcinomas (NSCLC) was maintained in agar overlay culture as tumour fragment spheroids for 40 days. A practical procedure for the formation of spheroids and organ culture is described. The mechanically dissociated tumour specimens showed a variation in their ability to generate spheroids that was not related to the ploidy or the histological differentiation of the biopsies. Light microscopic observations revealed a heterogeneous spheroid population with a mixture of tumour cells and stromal elements. Most of the histological elements normally found in human NSCLC could be seen in the spheroids. The cellular components in the spheroids varied between highly cellular to sparsely cellular, dominated by stromal elements. The squamous carcinomas were in general found to generate highly cellular spheroids more often than the adenocarcinomas. Spheroids with a different cellular content could be selected in vitro by using a morphometric technique. Diameter measurements showed a large variability in spheroid growth. Most of the spheroids decreased in size although bromodeoxyuridine labelling indicated active cell proliferation in the specimens. Frequent changes of medium did not affect spheroid growth. The culture system presented provides a model for studying the cellular heterogeneity as well as the biological characteristics of tumour tissue from individual patients in vitro.