Longitudinal Monitoring of Circulating Tumor DNA From Plasma in Patients With Curative Resected Stages I to IIIA EGFR-Mutant Non-Small Cell Lung Cancer.

INTRODUCTION: For patients with early stage EGFR-mutant-positive (EGFR-M+) NSCLC, curative surgery followed by adjuvant chemotherapy is considered the standard of care. This study evaluated the feasibility and efficacy of longitudinal monitoring of circulating tumor DNA (ctDNA) as a valuable biomarker for early detection of minimal residual disease (MRD) and provides identification of the group at high risk for recurrence in resected stages I to IIIA EGFR-M+ NSCLC. METHODS: Between August 2015 and October 2017, a total of 278 patients with curative resected, stages I to IIIA (American Joint Committee on Cancer seventh version) common EGFR-M+ NSCLC were analyzed. Radiological follow-up was accompanied with longitudinal monitoring of ctDNA using a droplet-digital polymerase chain reaction from baseline (preoperative), 4 weeks after curative surgery, and follow-up per protocol until 5 years. The primary outcomes were disease-free survival (DFS) according to the status of ctDNA positivity at landmark points and the sensitivity of longitudinal monitoring of ctDNA. RESULTS: Among 278 patients, preoperative baseline ctDNA was detected in 67 (24%) patients: 23% (stage IA), 18% (IB), 18% (IIA), 50% (IIB), and 42% (IIIA) (p = 0.06). Of patients with baseline ctDNA, 76% (51 of 67) had clearance at 4 weeks after surgery (postoperative). Patients were classified into the following three groups; group A, baseline ctDNA negative (n = 211) versus group B, baseline ctDNA positive but postoperative MRD negative (n = 51) versus group C, baseline ctDNA positive and postoperative MRD positive (n = 16). The 3-year DFS rate was significantly different among the three groups (84% for group A, 78% for group B, and 50% for group C, p = 0.02). After adjusting for clinicopathologic variables, ctDNA still remains an independent risk factor for DFS along with stage (p < 0.001) and micropapillary subtype (p = 0.02). With longitudinal monitoring of ctDNA, MRD was detected before radiological recurrence in 69% of patients with exon 19 deletion and in 20% with L858R mutation. CONCLUSIONS: These results suggest that patients with baseline ctDNA-positive or MRD-positive status were associated with poor DFS in curative resected stages I to IIIA EGFR-M+ NSCLC and that longitudinal monitoring of ctDNA, a noninvasive method, might be useful to detect early recurrence before radiological recurrence.

Impaired induction of cystatin S gene expression by isoproterenol in the submandibular gland of hypophysectomized rats.

Cystatin S, an inhibitor of cysteine proteases, is produced and secreted by acinar cells of the rat submandibular gland. Expression of the cystatin S gene is known to be induced at high levels by the beta-adrenergic agonist isoproterenol. In the present study, we revealed that in the submandibular gland of hypophysectomized adult male rats, the levels of induced cystatin S mRNA 24 h after a single administration of isoproterenol are strikingly lower than those in the gland of normal rats. Administration of one of the pituitary-dependent hormones testosterone, estradiol, dexamethasone and thyroxine, together with isoproterenol resulted in marked enhancement of the isoproterenol-induced cystatin S mRNA expression in hypophysectomized rats, whereas administration of any of these hormones alone had no significant effect. These results suggested the existence of cross-talk between the signaling pathways of steroid hormones and isoproterenol in inducing cystatin S gene expression in the rat submandibular gland.

Arsenic trioxide represses constitutive activation of NF-kappaB and COX-2 expression in human acute myeloid leukemia, HL-60.

It has been proposed that eukaryotic nuclear factor nuclear factor kappa-B (NF-kappaB) and cyclooxygenase-2 (COX-2) are implicated in the pathogenesis of many human diseases including cancer. Arsenic has been widely used in medicine in Oriental countries. Recent studies have shown that arsenic trioxide (As(2)O(3)) could induce in vitro growth inhibition and apoptosis of malignant lymphocytes, and myeloma cells. However, the molecular mechanisms by which As(2)O(3) initiates cellular signaling toward cell death are still unclear. In the present study, the effects of As(2)O(3) on NF-kappaB and COX-2 expression in HL-60 cells were investigated. As(2)O(3) suppressed DNA-binding activity of NF-kappaB composed of p65/p50 heterodimer through preventing the degradation of IkappaB-alpha and the nuclear translocation of p65 subsequently as well as interrupting the binding of NF-kappaB with their consensus sequences. Inhibitory effect of As(2)O(3) on NF-kappaB DNA activity was dependent upon intracellular glutathione (GSH) and H(2)O(2) level, but not superoxide anion. Futhermore, we found that As(2)O(3) also downregulated the expression of COX-2, which has NF-kappaB binding site on its promoter through repressing the NF-kappaB DNA-binding activity.

Importance of open lung biopsy in the diagnosis of invasive pulmonary aspergillosis in patients with hematologic malignancies.

Invasive pulmonary aspergillosis is a serious infectious complication in immunocompromised patients. Recent reports indicate its favorable clinical outcomes by early diagnosis with chest computed tomography scan. We retrospectively analyzed our experiences with histopathological evaluation by open lung biopsy in 31 patients (32 cases) with hematologic malignancies, suspected of having invasive pulmonary aspergillosis clinically and radiologically. Although the initial computed tomography findings of all cases were highly indicative of invasive pulmonary aspergillosis by demonstrating nodules or masses with a halo sign (16 cases), segmental area of consolidation with ground-glass attenuation (7 cases), both nodules or masses with a halo sign and segmental area of consolidation with ground-glass attenuation (7 cases) and poorly defined centrilobular nodules (2 cases), we could histopathologically confirm invasive fungal infections only in 17 cases (53.1%) by open lung biopsy. There were 13 cases of invasive pulmonary aspergillosis, two cases of aspergilloma, and two cases of mucormycosis. No fungal hyphae were found in the other 15 cases: organizing pneumonia in seven cases, pulmonary hemorrhage in three cases, brochiolitis obliterans with organizing pneumonia in two cases, and CMV pneumonia, pulmonary tuberculosis, candida pneumonia in one case each, respectively. We could perform open lung biopsy without mortality and significant morbidity. In view of the low positive predictive value of chest computed tomography scan and the very low morbidity of open lung biopsy, this procedure is recommendable for the diagnosis of invasive pulmonary aspergillosis and determination of its treatment.

Expression of the fragile histidine triad gene in normal rat tissues and human kidney cancer cell lines.

The fragile histidine triad (FHIT) gene located in human chromosome 3p14.2 is a candidate tumor suppressor gene that has a diadenosine triphosphate (Ap3A) hydrolase activity, but its role in carcinogenesis remains uncertain. To investigate the role of FHIT in normal cells, specific polyclonal antibodies to recombinant rat FHIT protein were generated. Immunoblot analysis revealed the 17-kd FHIT protein was most abundantly expressed in kidney and liver, whereas heart, skeletal muscle, and adrenal gland expressed trace amounts. In kidney, immunohistochemical staining was strongly observed in distal convoluted tubule and collecting duct during postnatal growth period. By a nested reverse transcription-PCR analysis of FHIT from 2 human kidney cancer cell lines, four abnormal-sized FHIT transcripts, with deletion and/or insertion, were detected. These were derived from the results of exon skipping, and/or insertion of FHIT intron 5 sequence, or selection of cryptic splice site within the FHIT cDNA sequence 179-180. Taken together, our data indicate that FHIT expression is frequently altered in human kidney cancer cell lines by alternative splicing, and suggest that the FHIT protein may play a pivotal role in regulating intracellular metabolism of the distal convoluted tubule and collecting duct in maturity.