The efficacy and safety of anamorelin among patients with diabetes.

BACKGROUND: Anamorelin is a selective ghrelin receptor agonist approved for cancer cachexia in Japan. Little is known about predictors of anamorelin efficacy. This study aimed to assess the effect of diabetes on the efficacy and safety of anamorelin in patients with cancer cachexia. METHODS: Medical records of patients with advanced non-small-cell lung, gastric, pancreatic, or colorectal cancer who received anamorelin between January 2021 and March 2023 were retrospectively reviewed. The diabetic (DM) group included patients with a confirmed diagnosis of type 2 diabetes mellitus, random plasma glucose of ≥ 200 mg/dL, or hemoglobin A1c of ≥ 6.5%. The maximum body weight gain and adverse events during anamorelin administration were compared between the DM and non-DM groups. Patients with a maximum body weight gain ≥ 0 kg were classified as the responders. RESULTS: Of 103 eligible patients, 31 (30.1%) were assigned to the DM group. The DM group gained less weight (median of -0.53% vs. + 3.00%, p < 0.01) and had fewer responders (45.2% vs. 81.9%, p < 0.01) than the non-DM group. The odds ratio for non-response in the DM group was 6.55 (95% confidential interval 2.37-18.06, p < 0.01), adjusted by age and performance status. The DM group had a higher cumulative incidence of hyperglycaemic adverse events (72.2% vs. 6.3%, p < 0.01) and more discontinuations due to hyperglycaemic adverse events (25.8% vs. 4.2%, p < 0.01) than the non-DM group. CONCLUSIONS: Patients with diabetes and cancer cachexia are less likely to gain weight with anamorelin despite a high risk of hyperglycaemic adverse events.

Efficacy of second-line chemotherapy in patients with pulmonary large cell neuroendocrine carcinoma.

The efficacy of second-line chemotherapy in patients with pulmonary large cell neuroendocrine carcinoma (LCNEC) is unclear. This study aimed to evaluate the efficacy of second-line chemotherapy in patients with pulmonary LCNEC. We retrospectively reviewed patients with pulmonary LCNEC or possible LCNEC (pLCNEC) who received platinum-based chemotherapy as the first-line treatment. Among these patients, we evaluated the efficacy of second-line treatment by comparing patients with small cell lung cancer (SCLC group). Of the 61 patients with LCNEC or pLCNEC (LCNEC group) who received first-line chemotherapy, 39 patients were treated with second-line chemotherapy. Among the 39 patients, 61.5% received amrubicin monotherapy. The median progression-free survival (PFS) and overall survival (OS) in the LCNEC groups were 3.3 and 8.3 months, respectively. No significant differences in the PFS (hazard ratio [HR]: 0.924, 95% confidence interval [CI] 0.647-1.320; P = 0.664) and OS (HR: 0.926; 95% CI 0.648-1.321; P = 0.670) were observed between the LCNEC and SCLC groups. In patients treated with amrubicin, the PFS (P = 0.964) and OS (P = 0.544) were not different between both the groups. Second-line chemotherapy, including amrubicin, may be considered as a treatment option for patients with pulmonary LCNEC.

Surgical Treatment for Non-union of the Great Toe Proximal Phalanx Stress Fracture in an Adolescent Jumping Athlete.

Stress fractures of the proximal phalanx of the great toe are primarily attributed to repetitive shear forces, with the vertical ground reaction forces exerting several times the body weight. In the initial stages of injury, conservative management anticipates bone healing within approximately five weeks, followed by a gradual return to sports activities over an additional five weeks. Athletes presenting with pain in this region warrant a thorough evaluation for stress fractures to initiate timely conservative care. In instances of delayed healing or non-union, surgical intervention is indicated. However, literature on the management and optimal timing of surgery, particularly in adolescent athletes, remains sparse. This case report, complemented by a literature review, offers insights into management based on the patient's clinical course.

Concordance of ALK fusion gene-rearrangement between immunohistochemistry and next-generation sequencing.

BACKGROUND: Although various companion diagnostic tests of ALK fusion gene-rearrangement are approved, few reports have assessed the concordance of ALK fusion gene-rearrangement in two companion diagnostic tests: next-generation sequencing (NGS) testing and immunohistochemistry (IHC). METHODS: The samples evaluated for gene alterations using NGS testing between May 2019 and November 2021 were included in this study. The inclusion criteria were as follows: samples were diagnosed with non-small cell lung cancer; the results of the NGS analysis were informative; and samples had residual specimens for IHC. We performed IHC on the residual specimens and retrospectively collected sample characteristics from medical records. RESULTS: A total of 185 samples were analyzed using NGS. Twenty-six samples were excluded because of failure to analyze gene alterations using NGS, no residual samples, and inadequate IHC. We analyzed 159 samples. The major histological type was adenocarcinoma (115 samples). The number of surgical and transbronchial lung biopsy specimens was 59 and 56, respectively. ALK fusion gene-rearrangement was detected in four samples using NGS, and five were detected using IHC. The sensitivity and specificity of IHC referred to by NGS were 75.0% and 98.7%, respectively. The concordance rate between IHC and NGS was 98.1%. ALK rearrangement was detected in two patients using IHC but not using NGS. In addition, ALK rearrangement was detected in one patient using NGS but not using IHC. CONCLUSION: Our results suggest that IHC and NGS might be complementary tests. In patients suspected of harboring ALK fusion gene-rearrangement, it should be analyzed using another diagnostic method.

Relationship between patterns of immunohistochemical conventional neuroendocrine markers and efficacy of immune check point inhibitors in patients with extensive disease small cell lung cancer.

BACKGROUND: Which patients benefit from the addition of immune checkpoint inhibitors (ICIs) to chemotherapy for small cell lung cancer (SCLC) remains unclear. There have been few reports on the efficacy of ICIs based on conventional immunohistochemical neuroendocrine (NE) markers (synaptophysin, chromogranin A, and neural cell adhesion molecule [NCAM]). In the present study, we aimed to analyze the relationship between the expression of immunohistochemical NE markers and the efficacy of ICIs in patients with extensive disease (ED)-SCLC, to assess whether conventional NE markers are predictive of ICIs. METHODS: Patients with untreated ED-SCLC who received first-line therapy at the Shizuoka Cancer Center between November 2002 and July 2021 were retrospectively reviewed. We evaluated the efficacy of first-line chemotherapy according to the expression status of each immunohistochemical NE marker in patients treated with ICI plus chemotherapy (ICI-chemo group) and with chemotherapy alone (chemo group). RESULTS: A total of 227 patients were included in the ICI-chemo and chemo groups, respectively. The progression-free survival (PFS) tended to be better in patients in the ICI-chemo group than those treated with chemotherapy alone in patients with NE marker-positive SCLC. In particular, it was statistically significant in patients with chromogranin A-positive SCLC (p = 0.036). In patients with NE marker-negative SCLC, no significant differences were observed in PFS between the two groups. There were no significant differences in overall survival (OS), regardless of the expression of any conventional NE marker. CONCLUSION: Our study suggests that the efficacy of ICIs in addition to chemotherapy may be poor in patients with NE marker-negative SCLC.

Prognostic significance of tumor microenvironment assessed by machine learning algorithm in surgically resected non-small cell lung cancer.

BACKGROUND: A methodology to assess the immune microenvironment (IME) of non-small cell lung cancer (NSCLC) has not been established, and the prognostic impact of IME factors is not yet clear. AIMS: This study aimed to assess the IME factors and evaluate their prognostic values. METHODS AND RESULTS: We assessed CD8+ tumor-infiltrating lymphocyte (TIL) density, forkhead box protein P3+ (Foxp3+ ) TIL density, and programmed death receptor ligand-1 (PD-L1) tumor proportion score (TPS) using a machine-learning algorithm in whole-slide imaging (WSI). We dichotomized patients according to TIL density or TPS and compared their clinical outcomes. Between September 2014 and September 2015, 165 patients with NSCLC were enrolled in the study. We assessed IME factors in the epithelium, stroma, and their combination. An improvement in disease-free survival (DFS) was observed in the high CD8+ TIL density group in the epithelium, stroma, and the combination of both. Moreover, the group with high PD-L1 TPS in the epithelium showed better DFS than that with low PD-L1 TPS. In the multivariate analysis, the CD8+ TIL density in the combination of epithelium and stroma and PD-L1 TPS in the epithelium were independent prognostic factors (hazard ratio [HR] = 0.43; 95% confidence interval [CI] = 0.26-0.72; p = .001, HR = 0.49; 95% CI = 0.30-0.81; p = .005, respectively). CONCLUSION: Our approach demonstrated that the IME factors are related to survival in patients with NSCLC. The quantitative assessment of IME factors enables to discriminate patients with high risk of recurrence, who can be the candidates for adjuvant therapy. Assessing the CD8+ TIL density in the combination of epithelium and stroma might be more useful than their individual assessment because it is a simple and time-saving analysis of TILs in WSI.

Safety and efficacy of amrubicin with primary prophylactic pegfilgrastim as second-line chemotherapy in patients with small cell lung cancer.

BACKGROUND: Amrubicin (AMR) regimens have shown efficacy as second-line treatment in patients with small cell lung cancer (SCLC); however, adverse events such as febrile neutropenia (FN) sometimes preclude their use. Further, the safety and efficacy of AMR with primary prophylactic pegfilgrastim (P-PEG) have not been sufficiently evaluated. In this study, we evaluated the safety and efficacy of AMR with or without P-PEG as second-line chemotherapy for SCLC. METHODS: We retrospectively reviewed patients with SCLC who received AMR as second-line chemotherapy at Shizuoka Cancer Center, between December 2014 and November 2021. Based on presence/absence of P-PEG in their regimen, patients (n = 60) were divided into P-PEG (n = 21) and non-P-PEG groups, and their clinical outcomes were evaluated. RESULTS: Median of AMR treatment cycles was five (range: 1-39 cycles) in P-PEG group and four (range: 1-15 cycles) in non-P-PEG group. The incidence of FN (4.8% vs. 30.8%; p = 0.02) and AMR dose reduction because of adverse events (4.8% vs. 25.6%; p = 0.08) were lower in the P-PEG group than in the non-P-PEG group. The objective response rates were 52.4% and 30.8%, and median progression-free and overall survival were 4.7 and 3.0 months, and 9.6 and 6.8 months, in the P-PEG and non-P-PEG groups, respectively. CONCLUSIONS: AMR with P-PEG as second-line chemotherapy for SCLC reduced the incidence of FN at a maintained AMR dose intensity and was associated with favorable tumor responses and survival outcomes. P-PEG should be considered for patients treated with AMR for SCLC including refractory relapsed SCLC.

Amivantamab plus Chemotherapy in NSCLC with EGFR Exon 20 Insertions.

BACKGROUND: Amivantamab has been approved for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 20 insertions who have had disease progression during or after platinum-based chemotherapy. Phase 1 data showed the safety and antitumor activity of amivantamab plus carboplatin-pemetrexed (chemotherapy). Additional data on this combination therapy are needed. METHODS: In this phase 3, international, randomized trial, we assigned in a 1:1 ratio patients with advanced NSCLC with EGFR exon 20 insertions who had not received previous systemic therapy to receive intravenous amivantamab plus chemotherapy (amivantamab-chemotherapy) or chemotherapy alone. The primary outcome was progression-free survival according to blinded independent central review. Patients in the chemotherapy group who had disease progression were allowed to cross over to receive amivantamab monotherapy. RESULTS: A total of 308 patients underwent randomization (153 to receive amivantamab-chemotherapy and 155 to receive chemotherapy alone). Progression-free survival was significantly longer in the amivantamab-chemotherapy group than in the chemotherapy group (median, 11.4 months and 6.7 months, respectively; hazard ratio for disease progression or death, 0.40; 95% confidence interval [CI], 0.30 to 0.53; P<0.001). At 18 months, progression-free survival was reported in 31% of the patients in the amivantamab-chemotherapy group and in 3% in the chemotherapy group; a complete or partial response at data cutoff was reported in 73% and 47%, respectively (rate ratio, 1.50; 95% CI, 1.32 to 1.68; P<0.001). In the interim overall survival analysis (33% maturity), the hazard ratio for death for amivantamab-chemotherapy as compared with chemotherapy was 0.67 (95% CI, 0.42 to 1.09; P = 0.11). The predominant adverse events associated with amivantamab-chemotherapy were reversible hematologic and EGFR-related toxic effects; 7% of patients discontinued amivantamab owing to adverse reactions. CONCLUSIONS: The use of amivantamab-chemotherapy resulted in superior efficacy as compared with chemotherapy alone as first-line treatment of patients with advanced NSCLC with EGFR exon 20 insertions. (Funded by Janssen Research and Development; PAPILLON ClinicalTrials.gov number, NCT04538664.).

Continuous vs. Fixed 2-year Duration Immune Checkpoint Inhibitor Treatment of Patients With Non-Small Cell Lung Cancer: A Single Institution Database Analysis.

INTRODUCTION/BACKGROUND: The proper duration of immune checkpoint inhibitor (ICI) treatment for patients with advanced non-small cell lung cancer (NSCLC) remains unclear. Previously, sponsor-initiated clinical trials have more often used either a maximum 2-year fixed duration of ICI treatment or continuous treatment until documented disease progression. The study aimed to evaluate the association between ICI treatment duration (2-year fixed or continuous) and prognosis in patients with advanced NSCLC. PATIENTS AND METHODS: The medical records of 425 patients with NSCLC who received ICI before August 31, 2019 were retrospectively reviewed. RESULTS: No differences in time to treatment failure > 24 months (TTF-24) were detected between patients who underwent ICI treatment for > 2 years and patients who stopped ICI treatment at 2 years. Treatment-related adverse events tended to be higher in the patients with ICI treatment > 2 years. CONCLUSION: ICI treatment > 2 years did not significantly prolong the TTF compared with ICI treatment = 2 years, but it did increase the incidence of treatment-related adverse events.

The role of tunneling nanotubes during early stages of HIV infection and reactivation: implications in HIV cure.

Tunneling nanotubes (TNTs), also called cytonemes or tumor microtubes, correspond to cellular processes that enable long-range communication. TNTs are plasma membrane extensions that form tubular processes that connect the cytoplasm of two or more cells. TNTs are mostly expressed during the early stages of development and poorly expressed in adulthood. However, in disease conditions such as stroke, cancer, and viral infections such as HIV, TNTs proliferate, but their role is poorly understood. TNTs function has been associated with signaling coordination, organelle sharing, and the transfer of infectious agents such as HIV. Here, we describe the critical role and function of TNTs during HIV infection and reactivation, as well as the use of TNTs for cure strategies.

Immunohistochemical analysis of B7-H3 expression in patients with lung cancer following various anti-cancer treatments.

B7 homolog 3 protein (B7-H3), an immune checkpoint molecule belonging to the B7 family, has been studied as a target for the development of anti-cancer treatment; however, changes in B7-H3 expression during the clinical course remain unknown. This retrospective study aimed to investigate changes in B7-H3 expression of lung cancer specimens in patients with advanced lung cancer following various anti-cancer treatments. The immunohistochemistry (IHC) score was evaluated on a 0-3 scale, and B7-H3 expression was considered positive for grade ≥ 2. The difference in IHC scores before and after anti-cancer treatment was defined as the change in B7-H3 expression. Among 160 patients with lung cancer who received anti-cancer treatment, 88 (55%) and 101 (63%) had B7-H3 expression before and after anti-cancer treatment, respectively. Before treatment, B7-H3 expression was significantly more common in squamous cell carcinoma specimens than in adenocarcinoma specimens (95% vs. 49%, P < 0.001). Of the 19 patients with squamous cell carcinoma, 18 (95%) continued to have high (IHC score: 3) B7-H3 expression following treatment. In contrast, of the 130 patients with adenocarcinoma, 46 (35%) and 17 (13%) showed an increased and a decreased expression, respectively. Patients who received targeted therapy had a significant increase in B7-H3 expression compared with those who received chemotherapy alone (P = 0.015). Overall, squamous cell carcinoma specimens maintained high B7-H3 expression during the clinical course, whereas adenocarcinoma specimens showed changes in expression following anti-cancer treatments. Our results provide the basis for further studies on the development of anti-cancer treatments targeting B7-H3.

Validation of the initial brain metastasis velocity in non-small cell lung cancer at a single cancer center.

PURPOSE: The initial brain metastasis velocity (iBMV) was recently reported as a survival predictor after brain metastases (BM) in patients treated by stereotactic radiosurgery. In this study, we validated whether iBMV is a prognostic tool, regardless of treatment modality, in patients with non-small cell lung cancer (NSCLC) with metachronous BM. METHODS: We retrospectively reviewed consecutive 3,792 new lung cancer cases in which no BM was found on magnetic resonance (MR) screening between February 2014 and December 2019, and enrolled 176 NSCLC patients with subsequent BM. Overall survival (OS) was calculated from the date of MR to identify the time from BM to death. RESULTS: The median iBMV score was 1.9. We used an iBMV score of 2.0 as the cutoff level, as previously reported. An iBMV score ≥ 2.0 was significantly associated with older age, high neutrophil-to-lymphocyte ratio, and Stage IV (P = 0.04, 0.02, and 0.02, respectively). The median OS was 0.92 years. The median OS for patients with iBMV score ≥ 2.0 and < 2.0 were 0.59 years and 1.33 years, respectively (P < 0.001). Multivariate analysis showed that an iBMV score ≥ 2.0, ECOG performance status score of 1-3, Stage IV, and non-adenocarcinoma histology were independent poor prognostic factors (hazard ratio (HR), 1.94; P = 0.0001; HR, 1.53; P = 0.04; HR, 1.45; P = 0.04; and HR, 1.14; P = 0.03, respectively). Patients with iBMV scores of < 2.0 were more likely to undergo craniotomy or stereotactic irradiation. CONCLUSIONS: An iBMV score ≥ 2.0 is an independent predictor of survival in NSCLC patients with metachronous BM, regardless of the treatment modality.

Incidence and Treatment Outcome of Radiation Pneumonitis in Patients With Limited-stage Small Cell Lung Cancer Treated With Concurrent Accelerated Hyperfractionated Radiation Therapy and Chemotherapy.

Purpose: This study aimed to clarify the characteristics of and evaluate the risk factors for radiation pneumonitis (RP) induced by chemoradiation therapy (CRT) using accelerated hyperfractionated (AHF) radiation therapy (RT) in patients with limited-stage small cell lung cancer (LS-SCLC). Methods and Materials: Between September 2002 and February 2018, 125 patients with LS-SCLC were treated with early concurrent CRT using AHF-RT. Chemotherapy was comprised of carboplatin/cisplatin with etoposide. RT was administered twice daily (45 Gy/30 fractions). We collected data regarding onset and treatment outcomes for RP, and analyzed the relationship between RP and total lung dose-volume histogram findings. Uni- and multivariate analyses were performed to assess patient- and treatment-related factors for grade ≥2 RP. Results: The median age of patients was 65 years, and 73.6% of participants were men. In addition, 20% and 80.0% of participants presented with disease stage II and III, respectively. The median follow-up time was 73.1 months. Grades 1, 2, and 3 RP were observed in 69, 17, and 12 patients, respectively. Grades 4 to 5 RP were not observed. RP was treated with corticosteroids in patients with grade ≥2 RP, without recurrence. The median time from initiation of RT to onset of RP was 147 days. Three patients developed RP within 59 days, 6 within 60 to 89 days, 16 within 90 to 119 days, 29 within 120 to 149 days, 24 within 150 to 179 days, and 20 within ≥180 days. Among the dose-volume histogram parameters, the percentage of lung volume receiving >30 Gy (V30) was most strongly related to the incidence of grade ≥2 RP, and the optimal threshold to predict RP incidence was V30 ≥20%. On multivariate analysis, V30 ≥20% was an independent risk factor for grade ≥2 RP. Conclusions: The incidence of grade ≥2 RP correlated strongly with a V30 of ≥20%. Contrarily, the onset of RP induced by concurrent CRT using AHF-RT may occur later. RP is manageable in patients with LS-SCLC.

Efficacy and safety of carboplatin and etoposide in older extensive-stage small-cell lung cancer patients with a poor performance status.

Carboplatin plus etoposide is a standard treatment for older extensive-stage small-cell lung cancer (ES-SCLC) patients with performance status (PS) 2. However, older patients often exhibit poor PS (3, 4), and the treatment effect in them is poorly understood. To determine the therapeutic efficacy and safety of carboplatin plus etoposide therapy for this population, we retrospectively analyzed 63 patients with ES-SCLC with PS ≥2, aged ≥71 years, who had received first-line carboplatin plus etoposide therapy. We compared the treatment efficacy and safety in patients with baseline PS 2 versus those with PS 3-4. In the PS 2 (38 patients) and PS ≥3 (25 patients) groups, the overall response rate was 71.1% and 72.0%, median progression-free survival was 4.6 and 3.1 months, and overall survival was 7.7 and 5.1 months, respectively. PS improved to 0-1 post-treatment in 65.8% and 48.0% of the patients in the PS 2 and PS ≥3 groups, respectively. Patients with PS ≥3 showing improved PS had a progression-free survival of 6.1 months. A higher incidence of grade ≥3 decreased neutrophil counts, febrile neutropenia, and treatment-related death was observed in the PS ≥3 group. The progression-free survival of patients administered prophylactic granulocyte colony-stimulating factor (G-CSF) was 5.2 and 6.1 months in the PS2 and PS ≥3 groups. Overall, carboplatin plus etoposide therapy provided comparable tumor shrinkage, but shorter progression-free and overall survival in older ES-SCLC patients with PS ≥3 than in those with PS 2. Thus, supportive care, such as prophylactic G-CSF administration, may be necessary to ensure safety and survival.

The efficacy of a machine learning algorithm for assessing tumour components as a prognostic marker of surgically resected stage IA lung adenocarcinoma.

BACKGROUND: The importance of the stromal components in tumour progression has been discussed widely, but their prognostic role in small size tumours with lepidic components is not fully understood. Applying digital tissue image analysis to whole-slide imaging may enhance the accuracy and reproducibility of pathological assessment. This study aimed to evaluate the prognostic value of tumour components of lung adenocarcinoma by measuring the dimensions of the tumour consisting elements separately, using a machine learning algorithm. METHODS: Between September 2002 and December 2016, 317 patients with surgically resected, pathological stage IA adenocarcinoma with lepidic components were analysed. We assessed the whole tumour area, including the lepidic components, and measured the epithelium, collagen, elastin areas and alveolar air space. We analysed the prognostic impact of each tumour component. RESULTS: The dimensions of the epithelium and collagen areas were independent significant risk factors for recurrence-free survival (hazard ratio, 8.38; 95% confidence interval, 1.14-61.88; P = 0.037, and hazard ratio, 2.58; 95% confidence interval, 1.14-5.83; P = 0.022, respectively). According to the subgroup analysis when combining the epithelium and collagen areas as risk factors, patients with tumours consisting of both large epithelium and collagen areas showed significantly poor prognoses (P = 0.002). CONCLUSIONS: We assessed tumour components using a machine learning algorithm to stratify the post-operative prognosis of surgically resected stage IA adenocarcinomas. This method might guide the selection of patients with a high risk of recurrence.

Clinical impact of tumour burden on the efficacy of PD-1/PD-L1 inhibitors plus chemotherapy in non-small-cell lung cancer.

BACKGROUND: Programmed cell death 1 (PD-1)/programmed cell death ligand (PD-L1) inhibitors plus chemotherapy (ICI + Chemo) is the standard treatment for advanced non-small-cell lung cancer (NSCLC). However, the impact of tumour burden on the efficacy of ICI + Chemo remains unknown. METHODS: We retrospectively evaluated 92 patients with advanced NSCLC treated with ICI + Chemo. Tumour burden was assessed as the sum of the longest diameter of the target lesion (BSLD) and number of metastatic lesions (BNMLs). We categorised the patients into three groups based on the combined BSLD and BNML values. RESULTS: Sixty-eight patients (74%) had progressive disease or died. Forty-four patients (48%) in the low-BSLD group had a median progression-free survival (PFS) of 9.5 months, whereas patients in the high-BSLD group had a median PFS of 4.6 months (hazard ratio [HR] = 0.54, p = 0012). Twenty-five patients (27%) in the low-BNML group had a median PFS of 9.6 months, whereas patients in the high-BNML group had a median PFS of 6.5 months (HR = 0.51, p = 0.029). Low-BSLD and low-BNML were associated independently with improved PFS in multivariate analysis. Analysis of the tumour burden combined with BSLD and BNML revealed a trend towards improved PFS as the tumour burden decreased, with median PFS of 22.3, 8.7, and 3.9 months in the low- (N = 13), medium- (N = 42) and high-burden (N = 37) groups respectively. CONCLUSIONS: Our findings demonstrated that a high tumour burden negatively impacts the efficacy of ICI + Chemo in patients with advanced NSCLC.

A Glu-Glu-Tyr Sequence in the Cytoplasmic Tail of the M2 Protein Renders Influenza A Virus Susceptible to Restriction of the Hemagglutinin-M2 Association in Primary Human Macrophages.

Influenza A virus (IAV) assembly at the plasma membrane is orchestrated by at least five viral components, including hemagglutinin (HA), neuraminidase (NA), matrix (M1), the ion channel M2, and viral ribonucleoprotein (vRNP) complexes, although particle formation is observed with expression of only HA and/or NA. While these five viral components are expressed efficiently in primary human monocyte-derived macrophages (MDMs) upon IAV infection, this cell type does not support efficient HA-M2 association and IAV particle assembly at the plasma membrane. Both defects are specific to MDMs and can be reversed upon disruption of F-actin. However, the relationship between the two defects is unclear. Here, we examined whether M2 contributes to particle assembly in MDMs and if so, which region of M2 determines the susceptibility to the MDM-specific and actin-dependent suppression. An analysis using correlative fluorescence and scanning electron microscopy showed that an M2-deficient virus failed to form budding structures at the cell surface even after F-actin was disrupted, indicating that M2 is essential for virus particle formation at the MDM surface. Notably, proximity ligation analysis revealed that a single amino acid substitution in a Glu-Glu-Tyr sequence (residues 74 to 76) in the M2 cytoplasmic tail allowed the HA-M2 association to occur efficiently even in MDMs with intact actin cytoskeleton. This phenotype did not correlate with known phenotypes of the M2 substitution mutants regarding M1 interaction or vRNP packaging in epithelial cells. Overall, our study identified M2 as a target of MDM-specific restriction of IAV assembly, which requires the Glu-Glu-Tyr sequence in the cytoplasmic tail. IMPORTANCE Human MDMs represent a cell type that is nonpermissive to particle formation of influenza A virus (IAV). We previously showed that close proximity association between viral HA and M2 proteins is blocked in MDMs. However, whether MDMs express a restriction factor against IAV assembly or whether they lack a dependency factor promoting assembly remained unknown. In the current study, we determined that the M2 protein is necessary for particle formation in MDMs but is also a molecular target of the MDM-specific suppression of assembly. Substitutions in the M2 cytoplasmic tail alleviated the block in both the HA-M2 association and particle production in MDMs. These findings suggest that MDMs express dependency factors necessary for assembly but also express a factor(s) that inhibits HA-M2 association and particle formation. High conservation of the M2 sequence rendering the susceptibility to the assembly block highlights the potential for M2 as a target of antiviral strategies.

Biomechanical Role of Epsin in Influenza A Virus Entry.

Influenza A virus (IAV) utilizes clathrin-mediated endocytosis for cellular entry. Membrane-bending protein epsin is a cargo-specific adaptor for IAV entry. Epsin interacts with ubiquitinated surface receptors bound to IAVs via its ubiquitin interacting motifs (UIMs). Recently, epsin was shown to have membrane tension sensitivity via its amphiphilic H0 helix. We hypothesize this feature is important as IAV membrane binding would bend the membrane and clinical isolates of IAVs contain filamentous IAVs that may involve more membrane bending. However, it is not known if IAV internalization might also depend on epsin's H0 helix. We found that CALM, a structurally similar protein to epsin lacking UIMs shows weaker recruitment to IAV-containing clathrin-coated structures (CCSs) compared to epsin. Removal of the ENTH domain of epsin containing the N-terminus H0 helix, which detects changes in membrane curvature and membrane tension, or mutations in the ENTH domain preventing the formation of H0 helix reduce the ability of epsin to be recruited to IAV-containing CCSs, thereby reducing the internalization of spherical IAVs. However, internalization of IAVs competent in filamentous particle formation is not affected by the inhibition of H0 helix formation in the ENTH domain of epsin. Together, these findings support the hypothesis that epsin plays a biomechanical role in IAV entry.

Artificial Intelligence-Powered Prediction of ALK Gene Rearrangement in Patients With Non-Small-Cell Lung Cancer.

PURPOSE: Several studies reported the possibility of predicting genetic abnormalities in non-small-cell lung cancer by deep learning (DL). However, there are no data of predicting ALK gene rearrangement (ALKr) using DL. We evaluated the ALKr predictability using the DL platform. MATERIALS AND METHODS: We selected 66 ALKr-positive cases and 142 ALKr-negative cases, which were diagnosed by ALKr immunohistochemical staining in our institution from January 2009 to March 2019. We generated virtual slide of 300 slides (150 ALKr-positive slides and 150 ALKr-negative slides) using NanoZoomer. HALO-AI was used to analyze the whole-slide imaging data, and the DenseNet network was used to build the learning model. Of the 300 slides, we randomly assigned 172 slides to the training cohort and 128 slides to the test cohort to ensure no duplication of cases. In four resolutions (16.0/4.0/1.0/0.25 µm/pix), ALKr prediction models were built in the training cohort and ALKr prediction performance was evaluated in the test cohort. We evaluated the diagnostic probability of ALKr by receiver operating characteristic analysis in each ALKr probability threshold (50%, 60%, 70%, 80%, 90%, and 95%). We expected the area under the curve to be 0.64-0.85 in the model of a previous study. Furthermore, in the test cohort data, an expert pathologist also evaluated the presence of ALKr by hematoxylin and eosin staining on whole-slide imaging. RESULTS: The maximum area under the curve was 0.73 (50% threshold: 95% CI, 0.65 to 0.82) in the resolution of 1.0 µm/pix. In this resolution, with an ALKr probability of 50% threshold, the sensitivity and specificity were 73% and 73%, respectively. The expert pathologist's sensitivity and specificity in the same test cohort were 13% and 94%. CONCLUSION: The ALKr prediction by DL was feasible. Further study should be addressed to improve accuracy of ALKr prediction.