DNA methylation changes in atypical adenomatous hyperplasia, adenocarcinoma in situ, and lung adenocarcinoma

Background

Aberrant DNA methylation is common in lung adenocarcinoma, but its timing in the phases of tumor development is largely unknown. Delineating when abnormal DNA methylation arises may provide insight into the natural history of lung adenocarcinoma and the role that DNA methylation alterations play in tumor formation.

Methodology/Principal Findings

We used MethyLight, a sensitive real-time PCR-based quantitative method, to analyze DNA methylation levels at 15 CpG islands that are frequently methylated in lung adenocarcinoma and that we had flagged as potential markers for non-invasive detection. We also used two repeat probes as indicators of global DNA hypomethylation. We examined DNA methylation in 249 tissue samples from 93 subjects, spanning the putative spectrum of peripheral lung adenocarcinoma development: histologically normal adjacent non-tumor lung, atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS, formerly known as bronchioloalveolar carcinoma), and invasive lung adenocarcinoma. Comparison of DNA methylation levels between the lesion types suggests that DNA hypermethylation of distinct loci occurs at different time points during the development of lung adenocarcinoma. DNA methylation at CDKN2A ex2 and PTPRN2 is already significantly elevated in AAH, while CpG islands at 2C35, EYA4, HOXA1, HOXA11, NEUROD1, NEUROD2 and TMEFF2 are significantly hypermethylated in AIS. In contrast, hypermethylation at CDH13, CDX2, OPCML, RASSF1, SFRP1 and TWIST1 and global DNA hypomethylation appear to be present predominantly in invasive cancer.

Conclusions/Significance

The gradual increase in DNA methylation seen for numerous loci in progressively more transformed lesions supports the model in which AAH and AIS are sequential stages in the development of lung adenocarcinoma. The demarcation of DNA methylation changes characteristic for AAH, AIS and adenocarcinoma begins to lay out a possible roadmap for aberrant DNA methylation events in tumor development. In addition, it identifies which DNA methylation changes might be used as molecular markers for the detection of preinvasive lesions.     

Chronic pancreatitis, pancreatic adenocarcinoma and the black box in-between

Pancreatic cancer is a challenging disease for patients, doctors and researchers who for decades have searched for a cure for this deadly malignancy. Although existing mouse models of pancreatic cancer have shed light on the mechanistic basis of the neoplastic conversion of the pancreas, their impact in terms of offering new diagnostics and therapeutic modalities remains limited. Chronic pancreatitis is an inflammatory disease of the pancreas that is associated with a gradual damage of the organ and an increased risk of developing neoplastic lesions. In this review, we propose that detailed studies of chronic inflammatory processes in the pancreas will provide insights into the evolution of pancreatic cancer. This information may prove useful in the design of effective therapeutic strategies to battle the disease.     

DNA damage, superoxide, and mutant K-ras in human lung adenocarcinoma cells

DNA single-strand breaks (quantitative comet assay) were assessed to indicate ongoing genetic instability in a panel of human lung adenocarcinoma cell lines. Of these, 19/20 showed more DNA damage than a nontransformed cell line from human peripheral lung epithelium, HPL1D. DNA damage was significantly greater in those derived from pleural effusates vs those from lymph node metastases. DNA strand breaks correlated positively with superoxide (nitroblue tetrazolium reduction assay), and negatively with amount of OGG1, a repair enzyme for oxidative DNA damage. Levels of CuZn superoxide dismutase varied moderately among the lines and did not correlate with other parameters. A role for mutant K-ras through generation of reactive oxygen species was examined. Cells with mutant K-ras had significantly lower amounts of manganese superoxide dismutase (MnSOD) vs those with wild-type K-ras, but MnSOD protein correlated positively with superoxide levels. In a subset of cell lines with similar levels of MnSOD, comparable to those in HPL1D cells, K-ras activity correlated positively with levels of both superoxide and DNA strand breaks. These results suggest that persistent DNA damage in some lung adenocarcinoma cells may be caused by superoxide resulting from mutant K-ras activity, and that OGG1 is important for prevention of this damage.     

Early adulthood body mass index,cumulative smoking,and esophageal adenocarcinoma survival

BackgroundSmoking and obesity are esophageal adenocarcinoma (EAC) risk factors. However, the same risk factors may also affect biological aggressiveness and cancer outcomes. Our study evaluated the combined effects of early-adulthood obesity and cumulative smoking on the EAC survival.Patients and methodsIn two EAC cohorts, Toronto (TO; N = 235) and Boston (BO; N = 329), associations between early adulthood body mass index (EA-BMI), BMI at 1 year prior to diagnosis (BMI-1), and smoking with overall survival (OS) were assessed using Cox proportional hazard models, adjusted for relevant covariates.ResultsBoth cohorts were predominantly Caucasian (89%), male (88%), ever-smokers (73%) with locally advanced/metastatic EAC (78%), and good ECOG performance status (90%); median packyears was 34; median EA-BMI, 24; median BMI-1, 25. No relationships with survival were found with BMI-1. For smoking and EA-BMI, TO, BO, and combined TO-BO analyses showed similar associations: smoking conferred worse OS in the combined TO-BO cohort, with adjusted hazard ratios (aHR) of 1.22 (95%CI: 1.15–1.43;p < 0.0001) for each 20 pack-year increase. Likewise, EA-BMI ≥25 was associated with worse OS (EA-BMI of 25− < 30, aHR = 1.84,95%CI: 1.37–2.48; and EA-BMI > 30, aHR = 2.78, 95%CI: 1.94–3.99). Risk of death was also increased in remotely underweight patients with EA-BMI < 18.5 (aHR = 2.03,95%CI: 1.27–3.24), when compared to normal-EA-BMI (18 ≤ EA-BMI < 25).ConclusionsTwo key modifiable behaviors, elevated BMI in early adulthood and heavy cumulative smoking history are independently associated with increased mortality risk in two North American cohorts of EAC patients.     

Pulmonary enteric adenocarcinoma

Pulmonary enteric adenocarcinoma (PEAC) is an exceptionally rare subtype of non–small cell lung cancer (NSCLC). It is characterized by pathological features similar to those of colorectal adenocarcinoma. Most patients with PEAC have almost no special clinical manifestations, and it is often difficult to differentiate from metastatic colorectal adenocarcinoma (MCRC). As a special type of lung adenocarcinoma, PEAC has unique mutation expression and immune characteristics; its mutation profile shows higher Kirsten rat sarcoma viral oncogene (KRAS), human epidermal growth factor receptor-2 (HER2) , DNA mismatch repair(MMR) mutation rates, and much lower epidermal growth factor receptor (EGFR) rate. So in the future, targeted therapy may tend to be a new light in the treatment of PEAC. As for immunohistochemistry (IHC), CDX-2, villin, and CK7 are significantly positive in PEAC. This review focuses on the pathologic features, immunohistochemical examination, mutation analysis, diagnosis, treatment, and prognosis of PEAC.     

Sensitivity of human pancreatic adenocarcinoma tumor lines to chemotherapy, radiotherapy, and hyperthermia

BACKGROUND: Surgical treatment of pancreatic adenocarcinoma has failed to produce many cures secondary to high rates of intraperitoneal relapses and liver metastases. The aim of this ex vivo study was to evaluate the inherent chemosensitivity, radiosensitivity and hyperthermic sensitivity of pancreatic adenocarcinoma and to investigate the usefulness of a 3-(4,5-dimetylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay utilized in each sensitivity test. METHODS: Nine human pancreatic adenocarcinomas were tested ex vivo after growth in nude mice. After 72 hr of chemotherapy, radiotherapy and hyperthermia, efficacy was assessed using MTT assay to determine the ratio of surviving fraction of treated cells-to-that of untreated control cells (TIC ratio). RESULTS: Tumor sensitivities as measured by the IC50 (drug concentration producing 50% growth inhibition) varied largely between drugs, ranging larger than 3 x 10(5) ng/mL for 5-FU, larger than 1.5 x 10(2) ng/mL for MMC, 20 ng/mL to 1.4 x 10(3) ng/mL for ADM, and 80 ng/mL to 2.4 x 10(3) ng/mL for CDDP. D0 (dose of radiation reducing the surviving fraction to 37%) ranged from 3.2 to 8.3 Gy (mean +/- standard deviation; 5.8 +/- 1.6 Gy). For hyperthermia, the mean T50 (duration of hyperthermia reducing the surviving fraction to 50%) at 43 degrees C was 9.4 +/- 3.3 min 4.8 to 14.2 min). The T/C ratio at 43 degrees C for 12 min was less than that at 41 degrees C for 30 min (p = .01; the Wilcoxon signed-ranks test). No clear relationship among chemosensitivity, radiosensitivity, hyperthermic sensitivity and pathologic features could be established. CONCLUSIONS: Nine human pancreatic adenocarcinomas varied widely in their sensitivity to chemotherapies, especially for 5-FU. These results suggested that MTT assay may be useful in excluding some less sensitive cases of pancreatic cancer. For hyperthermia, sufficient therapeutic time and temperature may realize enough effect against pancreatic adenocarcinoma.     

Characterization of a human colonic adenocarcinoma cell line,LS123

Summary An epithelial cell line, LS123, was established in 1974 from the second in a series of three primary colonic tumors resected from a Caucasian female. The cell line is aneuploid, releases low concentrations of carcinoembryonic antigen (CEA), fails to grow progressively in nude mice, and forms colonies only in enriched semisolid medium developed for tumor stem cells. LS123 cells grow on confluent cell monolayers and in either low serum or serum-free medium. In the chick embryonic skin assay, LS123 cells grew as a well-differentiated abnormal colonic epithelium with little mitotic activity but with some indication of invasion. On floating collagen gels LS123 cells formed a one to three-cell-layer-thick undifferentiated epithelial sheet. The apparent low invasiveness of the cells of this line is supported by the patient's history of three primary colon tumors without systemic metastases during the past 30 yr. Therefore, although LS123 cells possess several properties associated with neoplasia, they have little invasive potential. Thus, LS123 cells may represent an important model for the study of human colon cancer. Presented in part at the 33rd Annual Meeting of the Tissue Culture Association, San Diego, CA, June 6–10, 1982. The work has been partially supported by U.S. Public Health Service Grants CA23871 (L. P. R.), CA24024 and RCDAK04-CA00579 (B. H. T.), and CA27124 and CA22370 (B. D. K.); the latter was awarded through the National Large Bowel Cancer Project.     

HPAC,a new human glucocorticoid-sensitive pancreatic ductal adenocarcinoma cell line

Summary A new human pancreatic cancer (HPAC) cell line was established from a nude mouse xenograft (CAP) of a primary human pancreatic ductal adenocarcinoma. In culture, HPAC cells form monolayers of morphologically heterogenous, polar epithelial cells, which synthesize carcinoembryonic antigen, CA 19-9, CA-125, cytokeratins, antigens for DU-PAN-2, HMFG1, and AUA1, but do not express chromogranin A or vimentin indicative of their pancreatic ductal epithelial cell character. In the presence of serum, HPAC cell DNA synthesis was stimulated by insulin, insulin growth factor-I, epidermal growth factor, and TGF-&#x03B1; but inhibited by physiologic concentrations of hydrocortisone and dexamethasone. Dose-dependent inhibition of DNA synthesis was limited to steroids with glucocorticoid activity. The inhibitory effect of dexamethasone was abolished by the glucocorticoid antagonist RU 38486. Binding of [³H]dexamethasone to cytosolic proteins was specific and saturable at 4&#x00B0; C. Scatchard analysis of binding data demonstrated a single class of high-affinity binding sites (K_d=3.8&#x00B1;0.9 nM; B_max=523&#x00B1;128 fmol/mg protein). Western blot analysis revealed a major protein band that migrated at a M_r of 96 kDa. Northern blot analysis identified an mRNA of approximately 7 kilobases which hybridized with a specific glucocorticoid receptor complementary DNA probe (OB7). These findings support a role for glucocorticoids in the regulation of human malignant pancreatic cell function.     

Human colonic adenocarcinoma cells

Summary A series of human colonic epithelial cell lines have been cultured from a single patient: LS-180 the original adenocarcinoma, LS-174T a trypsinized variant, and normal colonic tissue. The malignant cells, 20 to 40 μm in diameter and oval to polygonal, exhibited characteristics of normal colonic mucosal cells, namely, abundant microvilli prominent in secretory cells, and the presence of intracytoplasmic mucin vacuoles. The cultured adenocarcinoma cells, but not normal, demonstrated neoplastic properties by producing high levels of carcinoembryonic antigen (CEA) and by the ability to be propagated in hamster cheek pouches and in immunodeprived mice. The CEA production by the newly established line LS-180 released 900 times more CEA per cell into the culture medium and bore 30 times more cell-associated material than the established line, HT-29. These cell lines may permit detection of distinctive chemical, physiological, pharmacologic, and immunologic characteristics of neoplastic colonic cells. The use of the term “line” conforms with the recent definitions published by Fedoroff in theTissue Culture Association Manual, Vol. 1, No. 1, pp. 53–57, 1975.     

Cytodiagnosis of gastric carcinoma, linitis plastica type (diffuse, infiltrating, poorly differentiated adenocarcinoma)

Two hundred seventy cases, with a total of 359 gastric samples, were reviewed. Fifteen cases of linitis plastica (diffuse, infiltrating, poorly differentiated adenocarcinoma) and 25 cases of other types of gastric cancer were identified. Four false-negative cases in the limits plastica group and nine false positives in the other group were studied. The sensitivity of cytologic evaluation in limits plastica was 73.3% and in other groups was 98%. Predictive value of positive results in linitis plastica was 100% but in the other group was 72.7%. The reasons for these findings are discussed.     

Pulmonary adenocarcinoma, Lambert--Eaton myasthenic syndrome, and voltage-gated calcium channels: a case report

ABSTRACT: INTRODUCTION: Lambert--Eaton myasthenic syndrome is a rare disorder and it is known as a paraneoplastic neurological syndrome. Small cell lung cancer often accompanies this syndrome. Lambert--Eaton myasthenic syndrome associated with lung adenocarcinoma is extremely rare; there are only a few reported cases worldwide. CASE PRESENTATION: A 75-year-old Japanese man with a past history of chronic rheumatoid arthritis and Sjogren syndrome was diagnosed with Lambert--Eaton myasthenic syndrome by electromyography and serum anti-P/Q-type voltage-gated calcium channel antibody level preceding the diagnosis of lung cancer. A chest computed tomography to screen for malignant lesions revealed an abnormal shadow in the lung. Although a histopathological examination by bronchoscopic study could not reveal the malignancy, lung cancer was mostly suspected after the results of a chest computed tomography and [18F]-fluorodeoxyglucose positron emission tomography. An intraoperative diagnosis based on the frozen section obtained by tumor biopsy was adenocarcinoma so the patient underwent a lobectomy of the right lower lobe and lymph node dissection with video-assisted thoracoscopic surgery. The permanent pathological examination was the same as the frozen diagnosis (pT2aN1M0: Stage IIa: TNM staging 7th edition). Immunohistochemistry revealed that most of the cancer cells were positive for P/Q-type voltage-gated calcium channel. CONCLUSIONS: Our case is a rare combination of Lambert--Eaton myasthenic syndrome associated with lung adenocarcinoma, rheumatoid arthritis and Sjogren syndrome, and to the best of our knowledge it is the first report that indicates the presence of voltage-gated calcium channel in lung adenocarcinoma by immunostaining.     

Liposome uptake into human colon adenocarcinoma cells in monolayer, spinner, and trypsinized cultures

The purpose of this study was to begin investigating the nature of liposome interactions with colon tumor cells. Thus, experiments were performed to study the uptake and incorporation of multilamellar and of reverse-phase evaporation liposomes of neutral charge into monolayers, suspended spinner cultures, and trypsinized cells of a human colon adenocarcinoma cell line, LS174T. The results showed that the same tumor cells cultured under each condition exhibited a distinct pattern of vesicle uptake as determined at 0, 15, 30, 60, and 120 min. In monolayer cultures of LS174T cells, the uptake of liposomes bearing [3H]actinomycin D in the lipid bilayers was linear throughout the incubation period. In contrast, in trypsinized and spinner suspension cultures, uptake of liposomes was biphasic. There was a proportional uptake of both liposome (labeled with [3H]phosphatidylcholine or [14C]cholesterol) and of actinomycin D (trace labeled with 3H) into the cells under all culture conditions, indicating quantitative delivery of the drug with the intact lipid vesicle. Although the amount of actinomycin D presented to tumor cells by the two liposomes was equivalent, reverse-phase evaporation liposomes were more effective than multilamellar vesicles in inhibiting uridine uptake. In the presence of excess liposomes (10 times the uptake studies), saturation of the tumor cell surface occurred by 120 min. However, the liposomes remained accessible to enzymatic removal for 60 min. Liposome-saturated tumor cells remained refractory to further binding of liposomes for at least 2 hr. The results thus revealed that differences in cell uptake were due to the state of the target cells and not the liposome types, or their differential leakage of labels.