Detection of resistance mutations in patients with anaplastic lymphoma kinase-rearranged lung cancer through liquid biopsy.

Background: Tyrosine kinase inhibitors (TKIs) significantly improve clinical outcomes in patients with non-small cell lung cancer due to anaplastic lymphoma kinase (ALK) gene rearrangement. However, the rate of relapse with TKIs is high owing to the development of resistance mutations during treatment. Repeated biopsies during disease progression are crucial for elucidating the molecular mechanisms underlying the development of resistance to ALK inhibitors. Analysis of cell-free DNA (cfDNA) obtained from plasma is a novel approach for tumor genotyping. Methods: In this mixed prospective and retrospective observational cohort study, we investigated the clinical feasibility of continuous quantitative monitoring of ALK-acquired mutations in plasma obtained from patients with ALK+ non-small cell lung cancer by using a highly sensitive and specific droplet digital polymerase chain reaction (ddPCR) assay. We enrolled nine patients, including three treatment-naïve patients recently diagnosed with ALK+ non-small cell lung cancer via tissue biopsy and expected to receive ALK TKIs and six patients already receiving ALK TKIs. Plasma samples were collected from these patients every 3 months. cfDNA was extracted from 66 samples during the study period, and 10 ALK mutations were simultaneously evaluated. Results: The numbers of samples showing the G1202R, C1156Y, G1269A, F1174L, T1151ins, and I1171T mutations were 32, 16, 5, 4, 1, and 1, respectively. The L1196M, L1152R, V1180L, and S1206Y mutations were not detected. Correlation analyses between progression-free survival and the time from treatment initiation (or treatment modification) to the detection of resistance mutations revealed that although resistance mutations may occur before a drug change becomes necessary, there is a duration during which the disease does not progress. Conclusions: Our findings suggest that real-time quantitative monitoring of ALK resistance mutations during the response period could provide a time course of changes while acquiring resistance mutations. This information would be beneficial for designing an appropriate treatment strategy.

Does the natural course of COVID-19 infection include radiographic cystic changes?

A patient with late phase of COVID-19 pneumonia presented peripheral cystic features on chest computed tomography, which were spontaneously resolved with no antibiotic therapy or surgery. Physicians should pay attention to follow up the late phase of COVID-19 pneumonia for better understanding its progression and clinical course.

Cyclin-dependent kinase 4 upregulation mediates acquired resistance of dabrafenib plus trametinib in BRAF V600E-mutated lung cancer.

BACKGROUND: Combination therapy with the B-Raf inhibitor, dabrafenib, and the MEK inhibitor, trametinib (DT) is commonly used to treat patients with B-Raf proto-oncogene, serine/threonine kinase V600E (BRAF V600E)-mutated non-small cell lung cancer (NSCLC). However, the mechanisms through which cancer develops DT resistance are unclear. Here, we investigated new mechanisms underlying acquired DT-resistant NSCLC with the BRAF V600E mutation. METHODS: We compared genomic signatures before and after DT treatment in patients with NSCLC. RESULTS: Two of four patients treated with DT developed carcinomatous pleuritis within 3 months. Target DNA sequencing and quantitative polymerase chain reaction (PCR) analyses revealed the increased expression level of cyclin-dependent kinase 4 (CDK4). We also found prominent protein expression of CDK4 after DT treatment. Induction of CDK4 expression in a cell line derived from a patient with the BRAF V600E mutation resulted in partial resistance to dabrafenib. CONCLUSIONS: Our findings suggest a possible relationship between CDK4 upregulation and acquired resistance to DT therapy.

A stealth antigen SPESP1, which is epigenetically silenced in tumors, is a suitable target for cancer immunotherapy.

Recent studies have revealed that tumor cells decrease their immunogenicity by epigenetically repressing the expression of highly immunogenic antigens to survive in immunocompetent hosts. We hypothesized that these epigenetically hidden "stealth" antigens should be favorable targets for cancer immunotherapy due to their high immunogenicity. To identify these stealth antigens, we treated human lung cell line A549 with DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5Aza) and its prodrug guadecitabine for 3 d in vitro and screened it using cDNA microarray analysis. We found that the gene encoding sperm equatorial segment protein 1 (SPESP1) was re-expressed in cell lines including solid tumors and leukemias treated with 5Aza, although SPESP1 was not detected in untreated tumor cell lines. Using normal human tissue cDNA panels, we demonstrated that SPESP1 was not detected in normal human tissue except for testis and placenta. Moreover, we found using immunohistochemistry SPESP1 re-expression in xenografts in BALB/c-nu/nu mice that received 5Aza treatment. To assess the antigenicity of SPESP1, we stimulated human CD4+ T-cells with a SPESP1-derived peptide designed using a computer algorithm. After repetitive stimulation, SPESP1-specific helper T-cells were obtained; these cells produced interferon-γ against HLA-matched tumor cell lines treated with 5Aza. We also detected SPESP1 expression in freshly collected tumor cells derived from patients with acute myeloid leukemia or lung cancer. In conclusion, SPESP1 can be classified as a stealth antigen, a molecule encoded by a gene that is epigenetically silenced in tumor cells but serves as a highly immunogenic antigen suitable for cancer immunotherapy.

A 47-Year-Old Woman With Pulmonary Nodules and Facial Hemispasms.

CASE PRESENTATION: A 47-year-old woman visited her primary physician for a health check, and some radiographic abnormalities were detected. She was referred to our division for further management. In recent years, she had become conscious of occasional facial hemispasms. She denied respiratory symptoms, smoking, alcohol consumption, and any particle inhalation. She had undergone oophorectomy and platinum-based chemotherapy because of ovarian cancer (serous cystadenocarcinoma stage Ⅰa) at the age of 29 years, with no recurrence for 17 years. The patient was diagnosed with rheumatoid arthritis (RA) 5 years before being seen by us and had been treated with bucillamine. No signs of RA progression were evident, and the only used antirheumatic drug was bucillamine. The patient had no history of use of immune-modulating drugs or immunosuppressants. No previous chest radiographs or CT had been performed.

Acute eosinophilic pneumonia following inhalation of turpentine oil: A case report.

Acute eosinophilic pneumonia (AEP) is an eosinophilic lung disease associated with environmental substances including smoking. Although the etiology of AEP has not been fully elucidated, it has been hypothesized that IL-33 plays a central role in the pathogenesis of AEP. Turpentine oil, from resins of pine trees, is not only used in paints, but also utilized in experimental animal models of inflammation because it leads to the production of inflammatory cytokines including IL-33. Here, we report the first case of AEP following turpentine oil inhalation. A 67-year-old woman reported using urushiol with turpentine oil to repair home goods. She had fever and persistent cough after turpentine inhalation over a very short period of time. The chest X-ray image showed consolidation in the upper right lung field. Laboratory findings indicated that there was no evidence of infection, collagen vascular diseases, and other allergic diseases that cause pneumonia, but analysis of the bronchoalveolar lavage fluid revealed 29% eosinophils with a small number of lipid-laden macrophages. With these findings, the diagnostic criteria of AEP was met. We rendered a diagnosis of AEP by inhalation of turpentine because no other cause for AEP was identified even with a structured questionnaire survey. The manifestations resolved immediately after steroid therapy. This is the first report of a case of AEP caused by the inhalation of turpentine oil.

Novel ALK-specific mRNA in situ hybridization assay for non-small-cell lung carcinoma.

BACKGROUND: A recent technical advance in mRNA in situ hybridization (mRNA-ISH) assays provides simultaneous signal amplification and background suppression with a unique probe design that enables single-molecule visualization. We assessed the utility of the mRNA-ISH assay as a diagnostic tool for detecting anaplastic lymphoma receptor tyrosine kinase (ALK) mRNA in non-small-cell lung carcinoma (NSCLC). We compared the mRNA-ISH assay with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). METHODS: The study included 279 surgically resected lung adenocarcinomas and 44 transbronchial-biopsied (TBB) adenocarcinomas. mRNA-ISH was conducted using the RNAscope 2.0 system, which includes pre-designed probes for detecting the tyrosine kinase domain encoded in ALK mRNA. IHC was conducted on all 323 samples using ALK-specific antibodies. mRNA-ISH was performed on 279 surgical samples and 6 TBB samples. Break-apart FISH was used to examine samples that were mRNA-ISH-positive or IHC-positive. RESULTS: ALK protein expression was detected in 11 of 279 specimens (3.9%). ALK mRNA was also detected with mRNA-ISH in ALK-positive samples, and 9 of the 11 specimens (81%) were also positive for ALK using break-apart FISH. Using the IHC results as a reference, the sensitivity and specificity of mRNA-ISH was 100%. In the TBB cohort, ALK protein expression was observed in 3 of 44 specimens (6.8%), in which ALK mRNA expression was also detected. CONCLUSIONS: The ALK mRNA-ISH data were highly correlated with the IHC data, and ALK mRNA-ISH detected ALK mRNA expression in every FISH-positive sample. We conclude that mRNA-ISH could serve as an alternative or complementary method for diagnosing ALK rearrangements in NSCLC.

Monomerization of ALK Fusion Proteins as a Therapeutic Strategy in ALK-Rearranged Non-small Cell Lung Cancers.

Objective: Oncogenic echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) (EML4-ALK) fusion proteins found in non-small cell lung cancers (NSCLC) are constitutively phosphorylated and activated by dimerization via the coiled-coil domain (cc) within EML4. Here, we investigated whether disruption of ALK fusion protein oligomerization via competitive cc mimetic compounds could be a therapeutic strategy for EML4-ALK NSCLC. Methods: A Ba/F3 cell model was created that expressed an ALK intracellular domain in which the dimer/monomer state is ligand-regulated. This novel cell model was used to investigate the effect of disrupting ALK fusion protein oligomerization on tumor cell growth in vitro and in vivo using nude mice. Subsequently, the antiproliferative effects of endogenous cc domain co-expression and mimetic cc peptides were assayed in EML4-ALK cancer cell lines. Results: Cells induced to express monomeric ALK in vitro did not survive. When transplanted into mice, induction of monomers abrogated tumor formation. Using a fluorescent protein system to quantify protein-protein interactions of EML4-ALK and EML4cc, we demonstrated that co-expression of EML4cc suppressed EML4-ALK assembly concomitant with decreasing the rate of tumor growth in vitro and in vivo. In EML4-ALK cancer cell lines, administration of synthetic EML4cc peptide elicited a decrease of phosphorylation of ALK leading to reduction in tumor cell growth. Conclusions: Our findings support the monomerization of ALK fusion proteins using EML4cc peptides for competitive inhibition of dimerization as a promising therapeutic strategy for EML4-ALK NSCLC. Further studies are warranted to explore the use of specific cc peptide as a therapeutic option for other lung cancers harboring driver fusion genes containing a cc or oligomerization domain within the fusion partner.

Observation of Zn-photoprotoporphyrin red Autofluorescence in human bronchial cancer using color-fluorescence endoscopy.

BACKGROUND: We observed red autofluorescence emanating from bronchial cancer lesions using a sensitive color-fluorescence endoscopy system. We investigated to clarify the origin of the red autofluorescence. METHODS: The wavelengths of the red autofluorescence emanating from lesions were measured in eight patients using a spectrum analyzer and compared based on pathologic findings. Red autofluorescence at 617.3, 617.4, 619.0, and 617.1 nm was emitted by normal bronchus, inflamed tissue, tissue exhibiting mild dysplasia, and malignant lesions, respectively. Protoporphyrin, uroporphyrin, and coproporphyrin, the major porphyrin derivatives in human blood, were purchased to determine which porphyrin derivative is the source of red fluorescence when acquired de novo. We synthesized photoporphyrin, Zn-protoporphyrin and Zn-photoprotoporphyrin from protoporphyrin. RESULTS: Coproporphyrin and uroporphyrin emitted only weak fluorescence. Fluorescence was emitted by our synthesized Zn-photoprotoporphyrin at 625.5 nm and by photoprotoporphyrin at 664.0 nm. CONCLUSIONS: From these results, we conclude that Zn-photoprotoporphyrin was the source of the red autofluorescence observed in bronchial lesions. Zn-protoporphyrin is converted to Zn-photoprotoporphyrin by radiation with excitation light. Our results suggest that red autofluorescence emanating from Zn-photoprotoporphyrin in human tissues could interfere with photodynamic diagnosis using porphyrin derivatives such as Photofrin® and Lazerphyrin® with a sensitive endoscopy system, because color cameras cannot differentiate Zn-photoprotoporphyrin red fluorescence from that of other porphyrin derivatives.

Interstitial lung disease associated with human papillomavirus vaccination.

Vaccinations against the human papillomavirus (HPV) have been recommended for the prevention of cervical cancer. HPV-16/18 AS04-adjuvanted vaccines (Cervarix) are said to have favourable safety profiles. Interstitial lung diseases (ILDs) can occur following exposure to a drug or a biological agent. We report a case of ILD associated with a Cervarix vaccination. A woman in her 40's, with a history of conisation, received three inoculations of Cervarix. Three months later, she presented with a cough and shortness of breath. Findings from a computed tomography of the chest and a transbronchial lung biopsy were consistent with non-specific interstitial pneumonia. Workup eliminated all other causes of the ILD, except for the vaccination. Over the 11 months of the follow-up period, her symptoms resolved without steroid therapy. The onset and spontaneous resolution of the ILD showed a chronological association with the HPV vaccination. The semi-quantitative algorithm revealed that the likelihood of an adverse drug reaction to Cervarix was "Probable". The outcome was relatively good, but more attention should be paid to a potential risk for HPV vaccinations to cause ILDs. Wherever possible, chest radiographic examinations should be performed in order not to overlook any ILDs.