Identification of age-dependent features of human bronchi using explainable artificial intelligence

Background

Ageing induces functional and structural alterations in organs, and age-dependent parameters have been identified in various medical data sources. However, there is currently no specific clinical test to quantitatively evaluate age-related changes in bronchi. This study aimed to identify age-dependent bronchial features using explainable artificial intelligence for bronchoscopy images.

Methods

The present study included 11 374 bronchoscopy images, divided into training and test datasets based on the time axis. We constructed convolutional neural network (CNN) models and evaluated these models using the correlation coefficient between the chronological age and the "bronchial age" calculated from bronchoscopy images. We employed gradient-weighted class activation mapping (Grad-CAM) to identify age-dependent bronchial features that the model focuses on. We assessed the universality of our model by comparing the distribution of bronchial age for each respiratory disease or smoking history.

Results

We constructed deep-learning models using four representative CNN architectures to calculate bronchial age. Although the bronchial age showed a significant correlation with chronological age in each CNN architecture, EfficientNetB3 achieved the highest Pearson's correlation coefficient (0.9617). The application of Grad-CAM to the EfficientNetB3-based model revealed that the model predominantly attended to bronchial bifurcation sites, regardless of whether the model accurately predicted chronological age or exhibited discrepancies. There were no significant differences in the discrepancy between the bronchial age and chronological age among different respiratory diseases or according to smoking history.

Conclusion

Bronchial bifurcation sites are universally important age-dependent features in bronchi, regardless of the type of respiratory disease or smoking history.

Successful control of intestinal bleeding from metastasis of pulmonary pleomorphic carcinoma with pembrolizumab: A case report

RATIONALE

Pulmonary pleomorphic carcinoma is a rare tumor with a poor prognosis and has no standard chemotherapy. We herein report a case of small intestinal metastasis of pulmonary pleomorphic carcinoma that resulted in intestinal bleeding and was successfully treated with pembrolizumab monotherapy.

PATIENT CONCERNS

A 54-year-old man with a history of pulmonary pleomorphic carcinoma resection was referred to our hospital due to a 1-month history of a fever and general fatigue.

DIAGNOSIS

Laboratory investigation revealed microcytic anemia. Hematochezia was also noted after admission. Computed tomography (CT) and positron emission tomography (PET)/CT at the time of this admission revealed intraperitoneal masses alongside the small intestine with no significant ascites.

INTERVENTIONS

Pembrolizumab (400 mg/body) was introduced as the first-line chemotherapy.

OUTCOMES

By the 15th day after the initial pembrolizumab administration, the fever had disappeared, and the intraperitoneal masses were markedly reduced. Hematochezia had also disappeared, and he no longer needed to receive blood transfusions.

LESSONS

To our knowledge, this is the first report in which small intestinal metastasis of pulmonary pleomorphic carcinoma was successfully controlled by pembrolizumab monotherapy. Immune checkpoint inhibitors may be promising therapeutic agents against pulmonary pleomorphic carcinoma.

Multiple cerebral infarctions in ROS1-rearranged lung adenocarcinoma

Rearrangements of specific tyrosine kinases are associated with an elevated risk of venous thrombosis in lung adenocarcinoma, although their effects on arterial thrombosis have not been fully elucidated. Here, we report two cases of ROS proto-oncogene 1 (ROS1)-rearranged lung adenocarcinoma with cerebral infarction during the peri-diagnostic period. Two cases took contrasting clinical courses: one patient could not receive targeted therapy because of a significant decline in performance status, whereas in the other patient, the performance status was maintained and targeted therapy drastically reduced the tumour size. Our cases suggest close monitoring could be considered in the selected cohort.

Cisplatin plus pemetrexed therapy and subsequent immune checkpoint inhibitor administration for malignant peritoneal mesothelioma without pleural lesions: Case report

RATIONALE

Malignant peritoneal mesothelioma is a rare tumor with a poor prognosis and has no recommended therapy after first-line pemetrexed and platinum-based chemotherapy. Moreover, effects of immune checkpoint inhibitors on peritoneal mesothelioma remains to be elucidated. We herein report the case of a 75-year-old man with peritoneal mesothelioma treated with cisplatin plus pemetrexed and subsequent nivolumab.

PATIENT CONCERNS

A 75-year-old man was referred to our hospital due to lower abdominal pain.

DIAGNOSIS

Positron emission tomography-computed tomography (CT) showed the accumulation of fluorodeoxyglucose in an intraperitoneal mass. A histological examination of a laparoscopic biopsy specimen revealed malignant peritoneal mesothelioma.

INTERVENTIONS

After 4 cycles of cisplatin plus pemetrexed and 13 subsequent cycles of pemetrexed maintenance therapy showed beneficial responses until CT revealed liver metastasis. Nivolumab was then administered as the second-line therapy.

OUTCOMES

After 3 cycles of biweekly nivolumab administration, he developed severe abdominal distention. CT revealed an intraperitoneal mass growing much more rapidly than ever, indicating hyperprogressive disease after nivolumab treatment. He ultimately died 51 days after the initial nivolumab administration.

LESSONS

To our knowledge, this is the first report of hyperprogressive disease in a case of peritoneal mesothelioma after nivolumab treatment. While immune checkpoint inhibitors may be promising therapeutic strategies for treating malignant peritoneal mesothelioma, careful monitoring must be practiced with their application.

Clinical Features of Patients with an Epidermal Growth Factor Receptor T790M Mutation Detected in Circulating Tumor DNA

BACKGROUND

Osimertinib, a third-generation epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), is effective against EGFR-mutated non-small cell lung carcinoma resistant to first- or second-generation EGFR-TKIs in patients in whom an EGFR T790M mutation has been detected. Detection of the T790M mutation using circulating tumor DNA (ctDNA) is less invasive than a tissue re-biopsy, including a transbronchial lung biopsy; however, the prognostic implications of the T790M mutation in ctDNA have not been fully elucidated.

METHODS

We retrospectively reviewed the clinical features of non-small cell lung carcinoma patients in whom an EGFR T790M mutation had been detected at our hospital and assessed the clinical outcomes of osimertinib for these patients in terms of detection sites.

RESULTS

An EGFR T790M mutation was detected in 32 non-small cell lung carcinoma patients, of whom 21 (65.6%) underwent osimertinib treatment after detection of the mutation. The mutation was detected using plasma samples in 10 patients (47.6%; liquid biopsy group), while it was detected using tissue samples in 11 patients (52.4%; tissue biopsy group). Liver and bone metastases were more frequently observed in patients in the liquid biopsy group than in the tissue biopsy group (30.0 vs. 0% and 60.0 vs. 18.2%, respectively). The median progression-free survival time was significantly shorter in the liquid biopsy group (132.0 days) than in the tissue biopsy group (682.0 days). The median overall survival time in the liquid biopsy group was 376.0 days, whereas that in the tissue biopsy group was not reached during our observation period.

CONCLUSIONS

Non-small cell lung carcinoma patients in whom an EGFR T790M mutation was detected in plasma samples demonstrated a poorer response to osimertinib than those in whom the mutation was detected in tissue specimens.

Successful Treatment of Afatinib-Refractory Non-Small Cell Lung Cancer with Uncommon Complex EGFR Mutations Using Pembrolizumab: A Case Report

Although there has been significant progress in immune-checkpoint inhibitor (ICI) treatment, it remains controversial whether they should be used in the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC). We herein report the case of an NSCLC patient with uncommon complex EGFR mutations (G719S and L861Q) who was refractory to afatinib treatment but who showed a good response to pembrolizumab treatment. A 65-year-old female ex-smoker was diagnosed with right upper lobe NSCLC (clinical stage IVB; cT2bN3M1c). She had received afatinib for two months, but her disease showed rapid progression. Pembrolizumab treatment was initiated because more than 75% of her tumor cells expressed PD-L1. Her tumor responded well to pembrolizumab treatment and it remained effective for more than 1 year. Our case suggests that pembrolizumab treatment is a treatment option for NSCLC patients with uncommon EGFR mutations and high PD-L1 expression levels who are refractory to EGFR-TKI treatment.

[Seven-Year Follow-Up of Advanced Gastric Carcinoma Treated Only with Chemotherapy Considering the Macroscopic Findings]

A 75-year-old woman presented with difficulty in swallowing. Esophagogastroduodenoscopy(EGD)revealed a Borrmann type 3 advanced gastric cardia carcinoma. Computed tomography(CT)revealed three lymph node metastases, and thus, the preoperative diagnosis was cT4aN2M0, cStage ⅢB. However, the patient refused resection, and chemotherapy was initiated. The chemotherapy regimen was sequentially changed based on the macroscopic characteristics of the lesion: S-1 plus CDDP followed by S-1 alone, S-1 plus PTX, and PTX alone. We have continued to follow-upthe lesion using EGD and CT, and have observed the macroscopic characteristics of the advanced gastric carcinoma treated without resection for 7 years.

Treatment outcome and safety of anti-PD-1 antibody against elderly non-small cell lung cancer

e14249

Background: The anti-PD-1 antibodies, Pembrolizumab (Pem) and Nivolumab (Nivo), have become available for practical clinical use in Japan, and many patients are benefiting from them. Lung cancer is predominantly a disease of the elderly people. However, the validity and safety of anti-PD-1 antibodies against the elderly are insufficient. Methods: From February 2016 to November 2018, 66 patients with non-small cell lung cancer who received anti-PD-1 antibody therapy (23 Pem and 43 Nivo) were evaluated for progression-free survival (PFS), overall survival (OS), and safety were compared between groups between the aged ≥75 years (≥75 yrs) and < 75 years ( < 75 yrs). Results: The median age (width) was 67 years (46-87 years). 46 patients were < 75 yrs and 20 patients were ≥75 yrs. PFS was 3.3 months (m) vs. 4.4 m ( < 75 yrs vs. ≥75 yrs)(p = 0.214). OS was 11.7 m vs. 16.7 m ( < 75 yrs vs. ≥75 yrs)(p = 0.212). Similar analysis was carried out for each anti-PD-1 antibody. In Pem, 15 patients were < 75 yrs and 8 patients were ≥75 yrs, and there was no significant difference between PFS and OS (p = 0.46, p = 0.17, respectively). In Nivo, 31 patients < 75 yrs, 12 patietns > 75 yrs, and there was no significant difference in PFS and OS (p = 0.49, p = 0.44, respectively). Immunity-related adverse events (irAE) was expressed in 25 patients (37.9%). Among 66 patients, 19 in 46 (41%) were < 75 yrs, 6 in 20 (30%) were ≥75yrs. There were not many irAEs even in the elderly people (χ2= 0.757, p = 0.384). Conclusions: Pem and Nivo proved to be effective and safe for the elderly patients even in the clinical setting.

Lung spindle cell carcinoma harbouring a constitutively active epidermal growth factor receptor mutation

Lung spindle cell carcinoma is a rare lung tumour with a poor prognosis, and its standard therapy has not been established. Furthermore, little work has been conducted on the genetic characteristics of lung spindle cell carcinomas. Here, we report an 82-year-old woman who was referred to our hospital due to a fever and dyspnoea. Chest computed tomography demonstrated a 75-mm mass surrounded by infiltrates and atelectasis in the right upper lobe. She was eventually diagnosed with lung spindle cell carcinoma corresponding to clinical stage IVB (cT4N2M1c(ADR)). A genetic study indicated that epidermal growth factor receptor (EGFR) exon 19 was deleted in the tumour cells. She received gefitinib as first-line therapy. However, no significant effect was observed, and she died of respiratory failure 89 days after the initial admission. To our knowledge, this is the first case of spindle cell carcinoma of the lung in which a sensitizing EGFR mutation is detected.

Severe pleuritis and pericarditis associated with very-late-onset systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem disorder, which occurs mostly in young women. However, late-onset SLE does exist and sometimes presents with an atypical, diversified course. We describe an 85-year-old woman who was admitted to our hospital for lower extremity edema and hand grip weakness. Chest computed tomography scan 4 days after admission demonstrated rapid accumulation of pleural and pericardial effusions, which did not exist on admission. She was diagnosed with pleuritis and pericarditis associated with very-late-onset SLE. Methylprednisolone pulse therapy resulted in a drastic improvement in serositis. Our case exemplifies the fact that patients with late-onset SLE sometimes follow an atypical course, which makes the clinical diagnosis difficult.

Recognition of tumor cells by Dectin-1 orchestrates innate immune cells for anti-tumor responses

The eradication of tumor cells requires communication to and signaling by cells of the immune system. Natural killer (NK) cells are essential tumor-killing effector cells of the innate immune system; however, little is known about whether or how other immune cells recognize tumor cells to assist NK cells. Here, we show that the innate immune receptor Dectin-1 expressed on dendritic cells and macrophages is critical to NK-mediated killing of tumor cells that express N-glycan structures at high levels. Receptor recognition of these tumor cells causes the activation of the IRF5 transcription factor and downstream gene induction for the full-blown tumoricidal activity of NK cells. Consistent with this, we show exacerbated in vivo tumor growth in mice genetically deficient in either Dectin-1 or IRF5. The critical contribution of Dectin-1 in the recognition of and signaling by tumor cells may offer new insight into the anti-tumor immune system with therapeutic implications.

DOI:http://dx.doi.org/10.7554/eLife.04177.001

When cells in the body grow and divide uncontrollably, cancerous tumors can form. An individual's likelihood of recovering from cancer is highly variable and often depends on the type of cancer and the extent of the disease at the start of treatment. Researchers are therefore interested in discovering how the body responds against cancerous cells.

The first line of defense against infection and disease is the body's innate immune system, which includes a suite of immune cells known as white blood cells. These cells patrol the body's organs and tissues in an effort to immediately respond to pathogens and damaged, stressed or otherwise abnormal host cells. Among white blood cells, natural killer cells are involved in identifying and destroying tumor cells. However, it was unclear whether or how other immune cells might help natural killer cells to destroy tumors. In addition, although immune cells detect pathogens and injured cells by producing proteins called pattern recognition receptors, it was unknown whether these receptors also detect tumor cells.

Here, Chiba et al. reveal that two other types of immune cell—dendritic cells and macrophages—play essential roles in helping natural killer cells to prevent tumors from growing in mice. The dendritic cells and macrophages produce a pattern recognition receptor called Dectin-1 that recognizes a molecule found on the surface of some—but not all—types of tumor cell. In doing so, Dectin-1 activates a critical signaling pathway and directs the activity of the natural killer cells so that they can effectively kill tumor cells. Chiba et al. found that these tumors grew faster in mice that lack the Dectin-1 protein.

The findings of Chiba et al. may also help to explain the effectiveness of certain antibodies—proteins that recognize and neutralize foreign objects such as bacteria and viruses—in cancer therapy. In addition, the Dectin-1 pathway presents a new avenue of research that may offer new cancer treatments.

DOI:http://dx.doi.org/10.7554/eLife.04177.002

The IRF family transcription factors at the interface of innate and adaptive immune responses

The interferon-regulatory factor (IRF) family, originally identified as transcriptional regulators of the type I interferon system, consists of nine members in mammals. A large number of studies have revealed the versatile and critical functions performed by this transcription factor family in immunity and other biological processes. Most notably, the advances in the study of signal transducing innate immune receptors have placed many IRF members as central mediators in the regulation of innate immune responses. In parallel, mechanistic studies have made it clearer that many IRFs exert their function either in cooperation or competition with other factors. In this article, we discuss current advances on the multipurpose and critical functions of IRFs in the regulation of innate immunity, particularly as they instruct adaptive immunity.

Oligodendrocyte transcription factor 1 (Olig1) is a Smad cofactor involved in cell motility induced by transforming growth factor-β

Transforming growth factor (TGF)-β plays crucial roles in embryonic development and adult tissue homeostasis by eliciting various cellular responses in target cells. TGF-β signaling is principally mediated through receptor-activated Smad proteins, which regulate expression of target genes in cooperation with other DNA-binding transcription factors (Smad cofactors). In this study, we found that the basic helix-loop-helix transcription factor Olig1 is a Smad cofactor involved in TGF-β-induced cell motility. Knockdown of Olig1 attenuated TGF-β-induced cell motility in chamber migration and wound healing assays. In contrast, Olig1 knockdown had no effect on bone morphogenetic protein-induced cell motility, TGF-β-induced cytostasis, or epithelial-mesenchymal transition. Furthermore, we observed that cooperation of Smad2/3 with Olig1 is regulated by a peptidyl-prolyl cis/trans-isomerase, Pin1. TGF-β-induced cell motility, induction of Olig1-regulated genes, and physical interaction between Smad2/3 and Olig1 were all inhibited after knockdown of Pin1, indicating a novel mode of regulation of Smad signaling. We also found that Olig1 interacts with the L3 loop of Smad3. Using a synthetic peptide corresponding to the L3 loop of Smad3, we succeeded in selectively inhibiting TGF-β-induced cell motility. These findings may lead to a new strategy for selective regulation of TGF-β-induced cellular responses.

Biology of transforming growth factor-β signaling

Transforming growth factor (TGF)-β signaling has been implicated as an important regulator of almost all major cell behaviors, including proliferation, differentiation, cell death, and motility. Which cell responses are induced or suppressed in response to TGF-β depends on the cell type and the context in which TGF-β signaling is received. TGF-β ligands, their receptors, and intracellular Smad effectors lie in the center of TGF-β signaling. TGF-β ligands signal via receptor serine/threonine kinases that phosphorylate and activate Smad proteins as well as other signaling molecules. Smad complexes associate with chromatin and regulate transcription, defining the biological response of a cell to TGF-β stimulation. In addition, numerous factors constitute complex networks to regulate TGF-β signaling and to provide this cytokine with the ability to induce cellular context-specific cell responses. Perturbation of the network is strongly involved in various pathological situations, including cancer and fibrosis. In this review, we consider the basic machinery of TGF-β signaling and describe several factors which make up TGF-β signaling networks. We also address major TGF-β-induced cell responses involved in several physiological and pathological conditions, including cell proliferation, fibrosis, and epithelial-mesenchymal transition.

Glioma-initiating cells retain their tumorigenicity through integration of the Sox axis and Oct4 protein

Although the concept of cancer stem cells or cancer-initiating cells had created a new paradigm for the treatment of malignant tumors, it remains unclear how cancer-initiating cells can be eradicated. We have previously reported that the transforming growth factor-β (TGF-β)-Sox4-Sox2 pathway is essential for glioma-initiating cells to retain their stemness, and inhibition of TGF-β signaling may lead to differentiation of glioma-initiating cells (Ikushima, H., Todo, T., Ino, Y., Takahashi, M., Miyazawa, K., and Miyazono, K. (2009) Cell Stem Cell 5, 504-514). Here we demonstrate that Oct4 plays essential roles in retention of the stemness properties of glioma-initiating cells through positive regulation of Sox2 expression. We also show that, in glioma-initiating cells, Oct4 is associated with Sox4 and that Oct4-Sox4 complexes cooperatively activate the enhancer activity of the SOX2 gene. In contrast, in fetal neural progenitor cells, Sox2 expression is enhanced by transcriptional complex containing Sox2 protein itself, and this self-reinforcing loop of Sox2 appears to be disrupted in glioma-initiating cells, suggesting that Sox2 expression in glioma-initiating cells is differently regulated from that in neural progenitor cells. Our findings reveal differences between glioma-initiating cells and fetal neural progenitor cells and may open the way to depriving glioma-initiating cells of tumorigenic activity without affecting normal tissues.

RB1CC1 protein positively regulates transforming growth factor-beta signaling through the modulation of Arkadia E3 ubiquitin ligase activity

Transforming growth factor-β (TGF-β) signaling is controlled by a variety of regulators, of which Smad7, c-Ski, and SnoN play a pivotal role in its negative regulation. Arkadia is a RING-type E3 ubiquitin ligase that targets these negative regulators for degradation to enhance TGF-β signaling. In the present study we identified a candidate human tumor suppressor gene product RB1CC1/FIP200 as a novel positive regulator of TGF-β signaling that functions as a substrate-selective cofactor of Arkadia. Overexpression of RB1CC1 enhanced TGF-β signaling, and knockdown of endogenous RB1CC1 attenuated TGF-β-induced expression of target genes as well as TGF-β-induced cytostasis. RB1CC1 down-regulated the protein levels of c-Ski but not SnoN by enhancing the activity of Arkadia E3 ligase toward c-Ski. Substrate selectivity is primarily attributable to the physical interaction of RB1CC1 with substrates, suggesting its role as a scaffold protein. RB1CC1 thus appears to play a unique role as a modulator of TGF-β signaling by restricting substrate specificity of Arkadia.

TGF-β signal transduction spreading to a wider field: a broad variety of mechanisms for context-dependent effects of TGF-β

Transforming growth factor (TGF)-β signaling is involved in almost all major cell behaviors under physiological and pathological conditions, and its regulatory system has therefore been vigorously investigated. The fundamental elements in TGF-β signaling are TGF-β ligands, their receptors, and intracellular Smad effectors. The TGF-β ligand induces the receptors directly to phosphorylate and activate Smad proteins, which then form transcriptional complexes to control target genes. One of the classical questions in the field of research on TGF-β signaling is how this cytokine induces multiple cell responses depending on cell type and cellular context. Possible answers to this question include cross-interaction with other signaling pathways, different repertoires of Smad-binding transcription factors, and genetic alterations, especially in cancer cells. In addition to these genetic paradigms, recent work has extended TGF-β research into new fields, including epigenetic regulation and non-coding RNAs. In this review, we first describe the basic machinery of TGF-β signaling and discuss several factors that comprise TGF-β signaling networks. We then address mechanisms by which TGF-β induces several responses in a cell-context-dependent fashion. In addition to classical frames, the interaction of TGF-β signaling with epigenetics and microRNA is discussed.

TGFbeta signalling: a complex web in cancer progression

The distortion of growth factor signalling is the most important prerequisite in tumour progression. Transforming growth factor-beta (TGFbeta) signalling regulates tumour progression by a tumour cell-autonomous mechanism or through tumour-stroma interaction, and has either a tumour-suppressing or tumour-promoting function depending on cellular context. Such inherent complexity of TGFbeta signalling results in arduous, but promising, assignments for developing therapeutic strategies against malignant tumours. As numerous cellular context-dependent factors tightly maintain the balance of TGFbeta signalling and contribute to the regulation of TGFbeta-induced cell responses, in this Review we discuss how they maintain the balance of TGFbeta signalling and how their collapse leads to tumour progression.

Autocrine TGF-beta signaling maintains tumorigenicity of glioma-initiating cells through Sry-related HMG-box factors

Despite aggressive surgery, radiotherapy, and chemotherapy, treatment of malignant glioma remains formidable. Although the concept of cancer stem cells reveals a new framework of cancer therapeutic strategies against malignant glioma, it remains unclear how glioma stem cells could be eradicated. Here, we demonstrate that autocrine TGF-beta signaling plays an essential role in retention of stemness of glioma-initiating cells (GICs) and describe the underlying mechanism for it. TGF-beta induced [corrected] expression of Sox2, a stemness gene, and this induction was mediated by Sox4, a direct TGF-beta target gene. Inhibitors of TGF-beta signaling drastically deprived tumorigenicity of GICs by promoting their differentiation, and these effects were attenuated in GICs transduced with Sox2 or Sox4. Furthermore, GICs pretreated with TGF-beta signaling inhibitor exhibited less lethal potency in intracranial transplantation assay. These results identify an essential pathway for GICs, the TGF-beta-Sox4-Sox2 pathway, whose disruption would be a therapeutic strategy against gliomas.

Cellular context-dependent "colors" of transforming growth factor-beta signaling

Transforming growth factor (TGF)-beta signaling has interesting characteristics in the context of cancer. Although perturbations of TGF-beta signaling are strongly implicated in cancer progression, TGF-beta signaling has both tumor-suppressive and tumor-promoting effects. For example, TGF-beta inhibits cancer cell proliferation in some cellular contexts, but promotes it in others. Although several approaches to treating cancer have been considered using TGF-beta-based therapeutic strategies, the contradictory behaviors of TGF-beta have made these approaches complex. To put them to practical use, either the tumor-suppressive or tumor-promoting arm needs to be specifically manipulated. However, there is virtually no method to specifically regulate a certain cell response induced by TGF-beta. In this review, we first consider the basic machinery of TGF-beta signaling, and describe several cell responses induced by TGF-beta stimulation in specific contexts. Mechanisms by which TGF-beta can induce several responses in a cellular context-dependent fashion are discussed with established paradigms and models. We also address perspectives on the specific control of only a subset of numerous cell responses induced by TGF-beta stimulation. Such methods will aid specific regulation of either the tumor-suppressive or tumor-promoting arm of the TGF-beta pathway and in realization of TGF-beta-based treatment of malignant tumors.

Efficacy and thyroidal effects of sunitinib in Japanese patients with metastatic renal cell carcinoma: Hypothyroidism and thyroid atrophy as potential biomarkers for sunitinib?

e16097

Background: Although hypothyroidism is a well-known adverse effect of sunitinib in western patients (pts) with metastatic renal cell carcinoma (MRCC), the effects on thyroid gland of sunitinib in Japanese pts still remain unclear. We therefore evaluated thyroid dysfunction and thyroid atrophy in Japanese RCC pts who received sunitinib. Methods: Fourteen (8 males, 6 females) of 51 pts who were treated in a phase II trial of sunitinib in Japanese pts with MRCC were included in this retrospective study. All 14 pts were euthyroid at baseline. The measurement of serum thyroid function test (fT3, fT4, TSH) was performed at the beginning of each sunitinib treatment cycle. A TSH concentration greater than 10 mU/L was considered as hypothyroidism regardless of subclinical or clinical. CT volumetry of the thyroid gland was performed utilizing the data obtained for tumor assessment in a phase II trial. Tumor response was evaluated based on the RECIST criteria. Results: 9 (64%) of 14 pts achieved RECIST-defined objective response (1 CR, 8 PRs). With regard to thyroid function, hypothyroidism was experienced by 11 (79%) pts. Three of 11 pts had Sunitinib-induced thyrotoxicosis before experiencing hypothyroidism. The mean time to development of hypothyroidism was 55 days (range 13–668). Six pts received typical doses of L-thyroxine. The response rate was 73% (8/11) in pts with hypothyroidism and 33% (1/3) in pts without. With regard to the volume of thyroid gland in 13 pts, 8 pts had more than 50% reduction comparing the volume at the baseline. Median reduction rate in volume of 13 pts was 57% (range 0–95%). Hypothyroidism was experienced by all 8 pts with more than 50% reduction in volume and 2 of 5 (40%) without. Furthermore, the response rate was 88% (7/8) in former pts and 40% (2/5) in latter pts. Conclusions: In addition to high anti-tumor efficacy, hypothyroidism and thyroid atrophy were commonly observed in Japanese MRCC pts who received sunitinib. Although further study should be required, these abnormal findings in thyroid gland following treatment with sunitinib may be potential biomarkers for tumor response to sunitinib.

[Table: see text]

Crystallization and preliminary X-ray diffraction analysis of GCIP/HHM transcriptional regulator

GCIP/HHM is a human nuclear protein that is implicated in regulation of cell proliferation. Its primary structure contains helix-loop-helix and leucine-zipper motifs but lacks a DNA-binding basic region. Native and selenomethionine-derivatized (SeMet) crystals of full-length GCIP/HHM were obtained using the hanging-drop vapour-diffusion method. The crystals were greatly improved by adding tris(2-carboxyethyl)phosphine as a reducing reagent and diffracted to 3.5 A resolution. Preliminary phase calculations using the data set obtained from the SeMet crystal suggested that the crystal belonged to space group P3(2)21 and contained one molecule per asymmetric unit. Structure determination by the multiple-wavelength anomalous dispersion method using the SeMet crystals is in progress.

An Id-like molecule, HHM, is a synexpression group-restricted regulator of TGF-beta signalling

Transforming growth factor (TGF)-β induces various cellular responses principally through Smad-dependent transcriptional regulation. Activated Smad complexes cooperate with transcription factors in regulating a group of target genes. The target genes controlled by the same Smad-cofactor complexes are denoted a synexpression group. We found that an Id-like helix-loop-helix protein, human homologue of Maid (HHM), is a synexpression group-restricted regulator of TGF-β signalling. HHM suppressed TGF-β-induced growth inhibition and cell migration but not epithelial–mesenchymal transition. In addition, HHM inhibited TGF-β-induced expression of plasminogen activator inhibitor-type 1 (PAI-1), PDGF-B, and p21^WAF, but not Snail. We identified a basic-helix-loop-helix protein, Olig1, as one of the Smad-binding transcription factors affected by HHM. Olig1 interacted with Smad2/3 in response to TGF-β stimulation, and was involved in transcriptional activation of PAI-1 and PDGF-B. HHM, but not Id proteins, inhibited TGF-β signalling-dependent association of Olig1 with Smad2/3 through physical interaction with Olig1. HHM thus appears to regulate a subset of TGF-β target genes including the Olig1-Smad synexpression group. HHM is the first example of a cellular response-selective regulator of TGF-β signalling with clearly determined mechanisms.

[Quality control (QC) of CT on rail system (FOCAL Unit) with a micro-multi leaf collimator (mMLC) using new GafChromic film for stereotactic radiotherapy]

PURPOSE

Recent years, CT on rail system was reported to be useful as a tool for image-guided radiotherapy (IGRT). This system was clinically developed with the aim of stereotactic irradiation (STI) for brain, lung, liver, prostate and other sites. Quality assurance and quality control (QC) is an important issue in CT on rail system to assure geometric accuracies. The purpose of this study is to estimate the geometric accuracies of our CT on rail system using a detachable micro-multi leaf collimator (mMLC) with new type radiochromic films. Carrying out our original QC program, translational errors, setup reproducibility, beam misalignment and beam characteristics were evaluated.

METHODS AND MATERIALS

We have studied with CT on rail system (FOCAL unit, Toshiba Medical systems, Tokyo, Japan) and mMLC unit (Accuknife, Direx Inc., Tokyo, Japan). We have developed original alignment phantom and small steel markers (2 mm phi) were implanted on its surface at certain intervals. Firstly, we have evaluated the accuracy of self-moving CT gantry and CT resolutions for cranio-caudal directions by changing slice thickness. And then using the phantom, we have measured the accuracy and reproducibility of geometric isocenter of the linac side and the CT gantry side by scanning the phantom. We have also measured the geometric changes of the common treatment couch by weight-loaded test (up to 135 kgw). To estimate dosimetric and geometric accuracies with the mMLC unit, the misalignment of the beam axes (gantry, collimator and couch rotation axis), mMLC leaf positions, and dose distributions for the verification plan were measured with new type GafChromic films (GafChromic-RTQA, ISP Inc., USA) and cylindrical phantom. The dose characteristics of the GafChromic film were also evaluated.

RESULTS

The reproducibility of the self-moving CT gantry have a good agreement within 1 mm. Weight-load test have shown a good reliability within 2 mm at the common treatment couch. The translational precision of the common treatment couch was 0.0 +/- 0.1 mm at linac side and -0.2 +/- 0.5 mm at CT gantry side. The misalignments of beam axes have been kept within 0.4 mm at maximum. Gap test have shown the accuracies of the mMLC leaf positions, which is needed to keep within 1 mm by a routine calibration.

CONCLUSIONS

To practice quality control program for the FOCAL unit and the mMLC unit is essential for a regular interval to reduce systematic errors. New type radiochromic film would be useful for a verification tool as alternative to conventional film.

Fractionated stereotactic radiotherapy of brain metastases from renal cell carcinoma

PURPOSE

To retrospectively evaluate the effectiveness of fractionated stereotactic radiotherapy (FSRT) for brain metastases from renal cell carcinoma (RCC).

METHODS AND MATERIALS

From May 1983 to September 1998, 35 patients with brain metastases from RCC underwent radiotherapy at the National Cancer Center Hospital, Tokyo; 10 patients treated initially with FSRT (FSRT group); 11 with surgery followed by conventional radiotherapy (S/CR group); and 14 with conventional radiotherapy (CR group). Survival and local control rates were determined for patients who had an ECOG performance status of 0-2.

RESULTS

Overall median survival rate was 18 months, and actuarial 1- and 2-year survival rates were 57.6% and 31.0%, respectively. Median survival rates were 25.6 months for the FSRT group, 18.7 months for the S/CR group, and 4.3 months for the CR group. Significant prognostic factors associated with survival were age less than 60 years and good performance status. In patients treated with FSRT, imaging studies revealed that 21 of 24 tumors (88%) were locally controlled during a median follow-up time of 5.2 months (range 0.5-68). Actuarial 1- and 2-year local control rates were 89.6% and 55.2%, respectively. No patient suffered from acute or late complications during and following FSRT.

CONCLUSIONS

FSRT offers better tumor control and prolonged survival over the S/CR or CR groups, and should be considered as primary treatment for brain metastases from RCC. Patients under 60-years-old and those with a good performance status at the beginning of radiotherapy had a better prognosis.

Internalization of CD26 by mannose 6-phosphate/insulin-like growth factor II receptor contributes to T cell activation

CD26 is a T cell activation antigen known to bind adenosine deaminase and have dipeptidyl peptidase IV activity. Cross-linking of CD26 and CD3 with immobilized mAbs can deliver a costimulatory signal that contributes to T cell activation. Our earlier studies revealed that cross-linking of CD26 induces its internalization, the phosphorylation of a number of proteins involved in the signaling pathway, and subsequent T cell proliferation. Although these findings suggest the importance of internalization in the function of CD26, CD26 has only 6 aa residues in its cytoplasmic region with no known motif for endocytosis. In the present study, we have identified the mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGFIIR) as a binding protein for CD26 and that mannose 6-phosphate (M6P) residues in the carbohydrate moiety of CD26 are critical for this binding. Activation of peripheral blood T cells results in the mannose 6 phosphorylation of CD26. In addition, the cross-linking of CD26 with an anti-CD26 antibody induces not only capping and internalization of CD26 but also colocalization of CD26 with M6P/IGFIIR. Finally, both internalization of CD26 and the T cell proliferative response induced by CD26-mediated costimulation were inhibited by the addition of M6P, but not by glucose 6-phosphate or mannose 1-phosphate. These results indicate that internalization of CD26 after cross-linking is mediated in part by M6P/IGFIIR and that the interaction between mannose 6-phosphorylated CD26 and M6P/IGFIIR may play an important role in CD26-mediated T cell costimulatory signaling.

CD26/dipeptidyl peptidase IV differentially regulates the chemotaxis of T cells and monocytes toward RANTES: possible mechanism for the switch from innate to acquired immune response

CD26, a 110 kDa cell surface glycoprotein, exhibits dipeptidyl peptidase IV (DPPIV; EC 3.4.14.5) enzyme activity and plays an important role in T cell co-stimulation. In the present study, the function of CD26/DPPIV in transendothelial migration was examined using beta-chemokines as chemoattractants. When soluble recombinant CD26 (sCD26/DPPIV+) was added to the transendothelial chemotaxis system, chemotactic migration of T cells toward RANTES was significantly enhanced. Addition of sCD26 to 50 ng/ml of RANTES enhanced the migratory response by a factor of two compared to RANTES alone, whereas mutant soluble CD26 (mCD26), lacking the DPPIV enzyme activity, had no enhancing effect on RANTES-induced T cell migration. In the process of analyzing the mechanisms of the enhancement of T cell migration by sCD26, we showed that RANTES was cleaved by sCD26 under physiologic conditions at the precise site characteristic of its enzyme specificity. However, synthesized RANTES which lacks two N-terminal amino acids showed a chemotactic activity equivalent to full-length RANTES on T cells. Furthermore, addition of sCD26 showed enhancement of T cell migration induced by both forms of RANTES. In contrast to T cells, the truncated RANTES is inactive in chemotaxis of purified monocytes and supplement of sCD26 but not mCD26 reduced the migratory response of monocytes to RANTES. These results suggest that CD26/DPPIV differentially regulate the chemotactic response of T cells and monocytes to RANTES.

Radiation Complications Following Breast Conserving Therapy

BACKGROUND: Breast conserving therapy is being established as a standard therapeutic procedure for early breast cancer in Japan. However, the indications of radiotherapy and a standardized therapeutic procedure have not been established yet. In this study, complications following radiotherapy were evaluated in patients who had previously undergone breast conserving therapy at Tokushima University Hospital. METHODS From October 1989 to March 1996, 60 women with stage I or II breast cancer underwent radiation therapy after breast conserving surgery, and all patients were followed-up for a median of 27 months. Radiation morbidity scoring of the breast and adjacent organs was performed using the toxity criteria of the Radiation Therapy Oncology Group (RTOG) and European Organization for Research andTreatment of Cancer (EORTC). RESULTS: Only 1 patient developed local recurrence, and no distant metastasisor death was observed. The cause of recurrence in 1 case was considered to be due to extended intraductal component. Although transient dermal reaction was induced by irradiation of the breast, no side effects that may cause cosmetic problems were found. No serious radiation complications were found in the lungs, ribs, heart or other adjacent organs. CONCLUSION: The adverse reactions caused by irradiation does not reduce the merit of combined use of radiation therapy in breast conserving therapy, and therefore, are not the hesitation factor in application of radiotherapy.

Detection of virulent Rhodococcus equi in tracheal aspirate samples by polymerase chain reaction for rapid diagnosis of R. equi pneumonia in foals

Polymerase chain reaction (PCR)-based assays were developed to detect virulent Rhodococcus equi in transtracheal aspirate samples from sick foals showing respiratory signs. An oligonucleotide primer pair from the sequence of the virulence-associated 15- to 17-kDa antigen gene of the virulence plasmid in virulent R. equi was used to amplify a 564 bp region by PCR, and the result was confirmed by Southern blot hybridization. No positive reaction was seen in DNA from 13 different microorganisms typically found in the respiratory tract. In tracheal aspirates seeded with virulent R. equi, a visible band could detect 10 to 10(2) bacteria per PCR assay (10(3) to 10(4)/ml of the aspirate). Virulent R. equi was demonstrated in 31 of 42 transtracheal aspirates by culture and colony blot analysis, whereas a positive PCR result was observed in only 12 of the 31 culture positive samples. To prevent false-negative results, two methods were developed: a nested PCR and a PCR in combination with enrichment cultures of aspirates in the selective medium to increase the number of bacteria to 10(4)/ml or more. All of the PCR-negative and culture-positive samples were positive by the two methods. These results indicated that PCR-based assays provide a specific and sensitive means to detect virulent R. equi in tracheal aspirates of foals, and they are more rapid than the routine culture procedures for the diagnosis of R. equi pneumonia in foals.

Different regulatory effects of pentoxifylline on human T cell activation pathways

Pentoxifylline (PTX), a methylxanthine derivative, was examined for its effects on T cell proliferation and cytokine production stimulated by cross-linking anti-CD3 alone, anti-CD3 with PMA, anti-CD3 with anti-CD26, or anti-CD3 with anti-CD28 mAb, respectively. PTX at a 3.5 x 10(-5) M concentration significantly inhibited T cell proliferation and the production of tumor necrosis factor-alpha, interleukin-2, and interleukin-4. Moreover, this effect was selective for stimulation by cross-linking anti-CD3 with PMA, or anti-CD3 with anti-CD26, but not by cross-linking anti-CD3 with anti-CD28. These results suggest that the inhibitory effect of PTX on T cell activation involves the CD3 and CD26, but not the CD28 signal pathway.

[Eight cases of intracranial arteriovenous malformations treated by conventional radiation therapy]

We conducted radiotherapy in 8 cases of intracranial arteriovenous malformation that had difficult embolectomy and other surgery from 1983 to October, 1988. The results in 6 cases of dural arteriovenous malformation at the cavernous sinus were "marked effect" in 4 cases, "relapse" in 1 case, and "no effect" in 1 case. One case of dural arteriovenous malformation at the sigmoid venous sinus demonstrated only slight irradiation effect. No irradiation effect was observed in 1 case of cerebral arteriovenous malformation.

Streptomyces auranticolor Sp. Nov., a new anticoccidial antibiotics producer

A new species of Streptomyces is described and designated Streptomyces auranticolor (FERM-P No. 5365) which produces new anticoccidial antibiotics, designated as WS-5995 A and WS-5995 B. The organism is characterized by gray spore mass color, spiral spore chain with smooth spores, non-chromogenic reaction, soluble pigment, and carbon utilization characteristics. It differs from previously described streptomycetes on the basis of carbon utilization, and pigment production.