Hyperpolarized Magnetic Resonance and Artificial Intelligence: Frontiers of Imaging in Pancreatic Cancer

BACKGROUND

There is an unmet need for noninvasive imaging markers that can help identify the aggressive subtype(s) of pancreatic ductal adenocarcinoma (PDAC) at diagnosis and at an earlier time point, and evaluate the efficacy of therapy prior to tumor reduction. In the past few years, there have been two major developments with potential for a significant impact in establishing imaging biomarkers for PDAC and pancreatic cancer premalignancy: (1) hyperpolarized metabolic (HP)-magnetic resonance (MR), which increases the sensitivity of conventional MR by over 10,000-fold, enabling real-time metabolic measurements; and (2) applications of artificial intelligence (AI).

OBJECTIVE

Our objective of this review was to discuss these two exciting but independent developments (HP-MR and AI) in the realm of PDAC imaging and detection from the available literature to date.

METHODS

A systematic review following the PRISMA extension for Scoping Reviews (PRISMA-ScR) guidelines was performed. Studies addressing the utilization of HP-MR and/or AI for early detection, assessment of aggressiveness, and interrogating the early efficacy of therapy in patients with PDAC cited in recent clinical guidelines were extracted from the PubMed and Google Scholar databases. The studies were reviewed following predefined exclusion and inclusion criteria, and grouped based on the utilization of HP-MR and/or AI in PDAC diagnosis.

RESULTS

Part of the goal of this review was to highlight the knowledge gap of early detection in pancreatic cancer by any imaging modality, and to emphasize how AI and HP-MR can address this critical gap. We reviewed every paper published on HP-MR applications in PDAC, including six preclinical studies and one clinical trial. We also reviewed several HP-MR-related articles describing new probes with many functional applications in PDAC. On the AI side, we reviewed all existing papers that met our inclusion criteria on AI applications for evaluating computed tomography (CT) and MR images in PDAC. With the emergence of AI and its unique capability to learn across multimodal data, along with sensitive metabolic imaging using HP-MR, this knowledge gap in PDAC can be adequately addressed. CT is an accessible and widespread imaging modality worldwide as it is affordable; because of this reason alone, most of the data discussed are based on CT imaging datasets. Although there were relatively few MR-related papers included in this review, we believe that with rapid adoption of MR imaging and HP-MR, more clinical data on pancreatic cancer imaging will be available in the near future.

CONCLUSIONS

Integration of AI, HP-MR, and multimodal imaging information in pancreatic cancer may lead to the development of real-time biomarkers of early detection, assessing aggressiveness, and interrogating early efficacy of therapy in PDAC.

Abstract 1009: On the role of DEAR1 as a novel ubiquitin ligase for ER alpha and predictor of tamoxifen response in ER positive breast cancer

Estrogen receptor positive (ER+) breast cancer accounts for over 70% of breast cancers. Targeted adjuvant therapies aimed at estrogen receptor have changed the natural history of the disease. However, over time many tumors develop resistance mechanisms which result in overall poor outcome. Thus, biomarkers that could predict response to antiestrogens are critically needed and would have major clinical impact. Thus, it is imperative that additional novel mechanisms be discovered not only to understand the basic underlying biology of ER alpha (ERα) signaling in order to identify genetic alterations that deregulate ERα and its role in breast cancer. DEAR1 is a tumor suppressor gene which is mutated, undergoes loss of heterozygosity in breast cancer. Previously we observed a subset of DEAR1 mutations in early onset breast cancers from premenopausal women, therefore we hypothesized that DEAR1 may function in the regulation of ERα signaling and conversely that mutations in DEAR1 (observed in human breast cancers) will abrogate that effect and could play a role in resistance to antiestrogen therapies. To test this hypothesis we studied the effect of DEAR1 expression on ERα. DEAR1 overexpression downregulated ERα expression and stability suggestive that DEAR1 may regulate ER signaling. DEAR1 interacted with ERα by immunoprecipitation and GST pulldown assays. Next we studied whether E3 ligase DEAR1 facilitates the degradation of ERα by promoting the ubiquitination of ERα. Our results indicate that DEAR1 promoted the polyubiquitination of ERα. To assess the effect of DEAR1 on estrogen mediated response, we examined the effect of DEAR1 on ERα-mediated transactivation using ERE-luciferase reporters. Results indicate that DEAR1 significantly inhibits estrogen-mediated transcriptional activity of ERα. We also studied the effect of DEAR1 in antiestrogen resistance using tamoxifen resistant cells. Preliminary results suggest that the presence of DEAR1 promoted the action of antiestrogen in tamoxifen resistant cell line. We have identified a new novel E3 ligase with regulatory effect of ERα signaling and potential implications in antiestrogen resistance.

Citation Format: Seetharaman Balasenthil, Nanyue Chen, Ann Killary. On the role of DEAR1 as a novel ubiquitin ligase for ER alpha and predictor of tamoxifen response in ER positive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1009.

Characterization of 11 human sarcoma cell strains: evaluation of cytogenetics, tumorigenicity, metastasis, and production of angiogenic factors

BACKGROUND

Human sarcomas have a propensity for aggressive local invasion and early pulmonary metastasis. Frequently, deaths are due to uncontrolled pulmonary metastases. The purpose of the current study was to evaluate cytogenetics, tumorigenicity, metastatic potential, and production of angiogenic factors in human sarcoma cell strains. A secondary purpose was to establish low passage cell strains for studying new therapeutic approaches.

METHODS

The authors established 11 cell strains from human sarcoma surgical specimens and characterized their in vitro tumor properties, including growth in soft agar, expression of angiogenic growth factors (vascular endothelial growth factor [VEGF] and basic-fibroblast growth factor [bFGF]), and cytogenetics.

RESULTS

All of the cell strains remained diploid. All exhibited the ability to grow in soft agar and expressed both VEGF as well as bFGF. In addition, 6 of the 11 established sarcoma cell strains were tumorigenic, 5 of which spontaneously metastasized to the lungs in nude mice. Four of the five cell strains that yielded lung metastases were derived from lung metastases in patients.

CONCLUSIONS

The 11 cell strains, which were derived from diverse sarcoma histologies, will provide a model for studying not only metastatic progression but also the in vitro and in vivo efficacy of new therapeutic modalities for human sarcomas.

Trisomy 5 as the sole chromosomal abnormality in a primary mucoepidermoid carcinoma of the minor salivary gland

We describe the cytogenetic findings in a moderately differentiated primary mucoepidermoid carcinoma of the base of the tongue. The only karyotypic abnormality found in the primary culture of this neoplasm was trisomy 5. This finding is remarkably different from previous cytogenetic studies of mucoepidermoid carcinomas, which have shown heterogeneous and unrelated chromosomal aberrations. Our results suggest that trisomy 5 may be an early aberration in the development of this neoplasm.