Tumor and serum DNA methylation in women receiving preoperative chemotherapy with or without vorinostat in TBCRC008.

BACKGROUND: Methylated gene markers have shown promise in predicting breast cancer outcomes and treatment response. We evaluated whether baseline and changes in tissue and serum methylation levels would predict pathological complete response (pCR) in patients with HER2-negative early breast cancer undergoing preoperative chemotherapy. METHODS: The TBCRC008 trial investigated pCR following 12 weeks of preoperative carboplatin and albumin-bound paclitaxel + vorinostat/placebo (n = 62). We measured methylation of a 10-gene panel by quantitative multiplex methylation-specific polymerase chain reaction and expressed results as cumulative methylation index (CMI). We evaluated association between CMI level [baseline, day 15 (D15), and change] and pCR using univariate and multivariable logistic regression models controlling for treatment and hormone receptor (HR) status, and performed exploratory subgroup analyses. RESULTS: In univariate analysis, one log unit increase in tissue CMI levels at D15 was associated with 40% lower chance of obtaining pCR (odds ratio, OR 0.60, 95% CI 0.37-0.97; p = 0.037). Subgroup analyses suggested a significant association between tissue D15 CMI levels and pCR in vorinostat-treated [OR 0.44 (0.20, 0.93), p = 0.03], but not placebo-treated patients. CONCLUSION: In this study investigating the predictive roles of tissue and serum CMI levels in patients with early breast cancer for the first time, we demonstrate that high D15 tissue CMI levels may predict poor response. Larger studies and improved analytical procedures to detect methylated gene markers in early stage breast cancer are needed. TBCRC008 is registered on ClinicalTrials.gov (NCT00616967).

A Large Postmortem Database of COVID-19 Patients Can Inform Disease Research and Public Policy Decision Making.

CONTEXT.­: Autopsies performed on COVID-19 patients have provided critical information about SARS-CoV-2's tropism, mechanisms of tissue injury, and the spectrum of disease. OBJECTIVE.­: To provide an updated database of postmortem disease in COVID-19 patients, assess relationships among clinical and pathologic variables, evaluate the accuracy of death certification, and correlate disease variables to causes of death. DESIGN.­: The 272 postmortem examinations reported in this paper were submitted by 14 pathologists from 9 medical or forensic institutions across the United States. The study spans the eras of the 3 principal COVID-19 strains and incorporates surveyed demographic, clinical, and postmortem data from decedents infected with SARS-CoV-2, including primary and contributing causes of death. It is the largest database of its kind to date. RESULTS.­: Demographics of the decedents reported here correspond well to national statistics. Primary causes of death as determined by autopsy and official death certificates were significantly correlated. When specifically cited disease conditions found at autopsy were correlated with COVID-19 versus non-COVID-19 death, only lung findings characteristic of SARS-CoV-2 infection or the absence of lung findings were significantly associated. CONCLUSIONS.­: Changes in hospitalization and disease likely stem from longer lifespans after COVID-19 diagnosis and alteration in treatment approaches. Although Omicron variants preferentially replicate in the upper airways, autopsied patients who died of COVID-19 in that time period showed the same lung damage as earlier decedents. Most importantly, findings suggest that there are still unelucidated risk factors for death from COVID-19 including possibly genetic susceptibility.

Non-invasive PD-L1 quantification using [18F]DK222-PET imaging in cancer immunotherapy.

BACKGROUND: Combination therapies that aim to improve the clinical efficacy to immune checkpoint inhibitors have led to the need for non-invasive and early pharmacodynamic biomarkers. Positron emission tomography (PET) is a promising non-invasive approach to monitoring target dynamics, and programmed death-ligand 1 (PD-L1) expression is a central component in cancer immunotherapy strategies. [18F]DK222, a peptide-based PD-L1 imaging agent, was investigated in this study using humanized mouse models to explore the relationship between PD-L1 expression and therapy-induced changes in cancer. METHODS: Cell lines and xenografts derived from three non-small cell lung cancers (NSCLCs) and three urothelial carcinomas (UCs) were used to validate the specificity of [18F]DK222 for PD-L1. PET was used to quantify anti-programmed cell death protein-1 (PD-1) therapy-induced changes in PD-L1 expression in tumors with and without microsatellite instability (MSI) in humanized mice. Furthermore, [18F]DK222-PET was used to validate PD-L1 pharmacodynamics in the context of monotherapy and combination immunotherapy in humanized mice bearing A375 melanoma xenografts. PET measures of PD-L1 expression were used to establish a relationship between pathological and immunological changes. Lastly, spatial distribution analysis of [18F]DK222-PET was developed to assess the effects of different immunotherapy regimens on tumor heterogeneity. RESULTS: [18F]DK222-PET and biodistribution studies in mice with NSCLC and UC xenografts revealed high but variable tumor uptake at 60 min that correlated with PD-L1 expression. In MSI tumors treated with anti-PD-1, [18F]DK222 uptake was higher than in control tumors. Moreover, [18F]DK222 uptake was higher in A375 tumors treated with combination therapy compared with monotherapy, and negatively correlated with final tumor volumes. In addition, a higher number of PD-L1+ cells and higher CD8+-to-CD4+ cell ratio was observed with combination therapy compared with monotherapy, and positively correlated with PET. Furthermore, spatial distribution analysis showed higher [18F]DK222 uptake towards the core of the tumors in combination therapy, indicating a more robust and distinct pattern of immune cell infiltration. CONCLUSION: [18F]DK222-PET has potential as a non-invasive tool for monitoring the effects of immunotherapy on tumors. It was able to detect variable PD-L1 expression in tumors of different cancer types and quantify therapy-induced changes in tumors. Moreover, [18F]DK222-PET was able to differentiate the impact of different therapies on tumors.

Expression of Akt and Mdm2 in human esophageal squamous cell carcinoma.

The Akt-Mdm2 pathway plays an important role in carcinogenesis in a variety of malignant tumors. However, the Akt-Mdm2 pathway in esophageal squamous cell carcinoma (ESCC) has not been fully studied. We investigated the proteins and mRNA expression of Akt and Mdm2 to elucidate the roles of these proteins in ESCC. We also examined the effect of Akt knockdown on Mdm2 expression in ESCC cells. ESCC tissue samples were obtained from 23 individuals who underwent surgical resection with no preoperative treatment. Akt1-3 and Mdm2 gene and protein expression were analyzed. The effect of siRNA-mediated Akt knockdown on Mdm2 expression was also studied, using ESCC cell lines. Akt1 and Mdm2 immunoreactivity was detected in 77.8 and 66.7% of tumor specimen from ESCC patients, respectively. Akt1 and Mdm2 mRNA expressions were correlated and significantly elevated in tumor tissue (p<0.0001 and p<0.05, respectively). The siRNA-targeted reduction of each Akt isoform reduced Mdm2 protein expression. The overexpression of Akt1 and Mdm2 may be related to esophageal carcinogenesis. Furthermore, Akt expression regulates Mdm2 expression, which may in turn regulate the function of wild-type p53. These results may provide the basis for future preventative or clinical therapies for esophageal cancer.

A comparison of FLT to FDG PET/CT in the early assessment of chemotherapy response in stages IB-IIIA resectable NSCLC.

BACKGROUND: The aim of this study was to compare the percentage change in 18F-fluorothymidine (FLT) standard uptake value (SUV) between baseline and after one cycle of chemotherapy in patients categorized by RECIST 1.1 computed tomography (CT) as responders or non-responders after two cycles of therapy. Change in 18F-fluorodeoxyglucose (FDG) uptake was also compared between these time points. Nine patients with newly diagnosed, operable, non-small cell lung cancer (NSCLC) were imaged with FDG positron emission tomography/CT (PET), FLT PET/CT, and CT at baseline, following one cycle of neoadjuvant therapy (75 mg/m2 docetaxel + 75 mg/m2 cisplatin), and again after the second cycle of therapy. All patients had a biopsy prior to enrollment and underwent surgical resection within 4 weeks of post-cycle 2 imaging. RESULTS: Between baseline and post-cycle 1, non-responders had mean SULmax (maximum standard uptake value adjusted for lean body mass) increases of 7.0 and 3.4% for FDG and FLT, respectively. Responders had mean decreases of 44.8 and 32.0% in FDG and FLT SULmax, respectively, between baseline and post-cycle 1 imaging. On post-cycle 1 imaging, primary tumor FDG SUL values were significantly lower in responders than in non-responders (P = 0.016). Primary tumor FLT SUL values did not differ significantly between these groups. Using the change from baseline to post-cycle 1, receiver-operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.94 for FDG and 0.78 for FLT in predicting anatomic tumor response after the second cycle of therapy. CONCLUSIONS: Fractional decrease in FDG SULmax from baseline to post-cycle 1 imaging was significantly different between anatomic responders and non-responders, while percentage changes in FLT SULmax were not significantly different between these groups over the same period of time.

Classification of proliferative pulmonary lesions of the mouse: recommendations of the mouse models of human cancers consortium.

Rapid advances in generating new mouse genetic models for lung neoplasia provide a continuous challenge for pathologists and investigators. Frequently, phenotypes of new models either have no precedents or are arbitrarily attributed according to incongruent human and mouse classifications. Thus, comparative characterization and validation of novel models can be difficult. To address these issues, a series of discussions was initiated by a panel of human, veterinary, and experimental pathologists during the Mouse Models of Human Cancers Consortium (NIH/National Cancer Institute) workshop on mouse models of lung cancer held in Boston on June 20-22, 2001. The panel performed a comparative evaluation of 78 cases of mouse and human lung proliferative lesions, and recommended development of a new practical classification scheme that would (a) allow easier comparison between human and mouse lung neoplasms, (b) accommodate newly emerging mouse neoplasms, and (c) address the interpretation of benign and preinvasive lesions of the mouse lung. Subsequent discussions with additional experts in pulmonary pathology resulted in the current proposal of a new classification. It is anticipated that this classification, as well as the complementary digital atlas of virtual histological slides, will help investigators and pathologists in their characterization of new mouse models, as well as stimulate further research aimed at a better understanding of proliferative lesions of the lung.

Regulation of fatty acid synthase expression in breast cancer by sterol regulatory element binding protein-1c.

Activation of fatty acid synthase (FAS) expression and fatty acid synthesis is a common event in human breast cancer. Sterol regulatory element binding proteins (SREBPs) are a family of transcription factors that regulate genes involved in lipid metabolism, including FAS. SREBP-1c expression is induced in liver and adipose tissue by insulin and by fasting/refeeding and is critical for nutritional regulation of lipogenic gene expression. In contrast, upregulation of fatty acid metabolism during in vitro transformation of human mammary epithelial cells and in breast cancer cells was driven by increased MAP kinase and PI 3-kinase signaling, which increased SREBP-1 levels. SREBP-1a was more abundant than SREBP-1c in many proliferative tissues and cultured cells and was thus a candidate to regulate lipogenesis for support of membrane synthesis during cell growth. We now show that SREBP-1c and FAS mRNA were both increased by H-ras transformation of MCF-10a breast epithelial cells and were both reduced by exposure of MCF-7 breast cancer cells to the MAP kinase inhibitor, PD98059, or the PI 3-kinase inhibitor, wortmannin, while SREBP-1a and SREBP-2 showed less variation. Similarly, the mRNA levels for FAS and SREBP-1c in a panel of primary human breast cancer samples showed much greater increases than did those for SREBP-1a and SREBP-2 and were significantly correlated with each other, suggesting coordinate regulation of SREBP-1c and FAS in clinical breast cancer. We conclude that regulation of FAS expression in breast cancer is achieved through modulation of SREBP-1c, similar to the regulation in liver and adipose tissue, although the upstream regulation of liopgenesis differs in these tissues.