Reevaluation of the medical necessity of washed red blood cell transfusion in chronically transfused adults

BACKGROUND

Washing red blood cell (RBC) units mitigates severe allergic transfusion reactions. However, washing reduces the time to expiration and the effective dose. Automated washing is time- and labor-intensive. A shortage of cell processor tubing sets prompted review of medical necessity for washed RBC for patients previously thought to require washing.

STUDY DESIGN AND METHODS

A single-center, retrospective study investigated discontinuing wash RBC protocols in chronically transfused adults. In select patients with prior requirements for washing, due to a history of allergic transfusion reactions, trials of unwashed transfusions were performed. Patient demographic, clinical, laboratory, and transfusion data were compiled. The per-unit washing cost was the sum of the tubing set, saline, and technical labor costs.

RESULTS

Fifteen patients (median age 34 years interquartile range [IQR] 23-53 years, 46.7% female) were evaluated. These patients had been transfused with a median of 531 washed RBC units (IQR 244-1066) per patient over 12 years (IQR 5-18 years), most commonly for recurrent, non-severe allergic reactions. There were no transfusion reactions with unwashed RBCs aside from one patient with one episode of pruritus and another with recurrent pruritus, which was typical even with washed RBC. We decreased the mean number of washed RBC units per month by 72.9% (104 ± 10 vs. 28.2 ± 25.2; p < .0001) and saved US $100.25 per RBC unit.

CONCLUSION

Washing of RBCs may be safely reconsidered in chronically transfused patients without a history of anaphylaxis. Washing should be implemented judiciously due to potential lack of necessity and logistical/operational challenges.

HMGA1 induces FGF19 to drive pancreatic carcinogenesis and stroma formation

High mobility group A1 (HMGA1) chromatin regulators are upregulated in diverse tumors where they portend adverse outcomes, although how they function in cancer remains unclear. Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors characterized by dense desmoplastic stroma composed predominantly of cancer-associated fibroblasts and fibrotic tissue. Here, we uncover an epigenetic program whereby HMGA1 upregulates FGF19 during tumor progression and stroma formation. HMGA1 deficiency disrupts oncogenic properties in vitro while impairing tumor inception and progression in KPC mice and subcutaneous or orthotopic models of PDAC. RNA sequencing revealed HMGA1 transcriptional networks governing proliferation and tumor-stroma interactions, including the FGF19 gene. HMGA1 directly induces FGF19 expression and increases its protein secretion by recruiting active histone marks (H3K4me3, H3K27Ac). Surprisingly, disrupting FGF19 via gene silencing or the FGFR4 inhibitor BLU9931 recapitulates most phenotypes observed with HMGA1 deficiency, decreasing tumor growth and formation of a desmoplastic stroma in mouse models of PDAC. In human PDAC, overexpression of HMGA1 and FGF19 defines a subset of tumors with extremely poor outcomes. Our results reveal what we believe is a new paradigm whereby HMGA1 and FGF19 drive tumor progression and stroma formation, thus illuminating FGF19 as a rational therapeutic target for a molecularly defined PDAC subtype.

Abstract 2414: HMGA1 induces FGF19 to drive tumor progression and recruit cancer associated fibroblasts in pancreatic adenocarcinoma

Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors characterized by a dense desmoplastic stroma comprised of cancer associated fibroblasts (CAFs) and fibrotic scar tissue. While stromal CAFs act as a barrier to therapy and release signals promoting tumor growth and invasion, the stroma restricts tumor growth in mouse models. The High Mobility Group A1 (HMGA1) protein is an oncofetal protein and epigenetic regulator that amplifies signals from the microenvironment to foster stem cell properties within intestinal epithelium. Although HMGA1 is highly expressed in embryonic and adult stem cells, it is silenced postnatally in most differentiated cells. HMGA1 becomes aberrantly re-expressed in diverse tumors where high levels predict adverse clinical outcomes. In PDAC, HMGA1 is detected only in late-stage precursor lesions or invasive tumors, but not in normal pancreas nor in early precursor lesions. Moreover, high HMGA1 nuclear staining associates with poor differentiation status and decreased patient survival. Here, we discovered a novel epigenetic program whereby HMGA1 recruits stromal CAFs and drives tumor progression by inducing FGF19. Silencing HMGA1 in PDAC cell lines slows proliferation, disrupts oncogenic properties in vitro (migration, invasion, clonogenicity, 3D sphere formation), and depletes tumor initiator cells in xenograft assays. RNA sequencing revealed transcriptional networks up-regulated by HMGA1 that function in cell signaling and proliferation; we focused on FGF19 as a potential mediator of tumor-stromal crosstalk. HMGA1 binds directly to the FGF19 promoter and recruits active histone marks (H3K4me2, H3K27Aac) to induce gene expression and protein secretion from PDAC cells. Silencing FGF19 recapitulates effects of HMGA1 silencing, disrupting oncogenic and cancer stem cell properties in vitro while depleting tumor initiator cells in vivo. In co-culture experiments, FGF19 is required for CAF migration across a membrane towards PDAC cells. Silencing HMGA1, FGF19, or treatment with FGF19 inhibitors disrupts CAF recruitment. Silencing HMGA1 or FGF19 in PDAC cells also decreases both the desmoplastic stroma and tumor growth in mouse xenografts. In primary tumors, co-expression of HMGA1 and FGF19 predict decreased survival. Together, our results reveal a novel paradigm whereby tumor cells collaborate with CAFs via HMGA1 and FGF19 to drive progression, thus illuminating FGF19 as a rational therapeutic target for PDACs overexpressing HMGA1 and FGF19.

Citation Format: Lionel Chia, Shuai Shuai, Jung-Hyun Kim, Woo Jung Sung, Ruitao Zhang, Tait Huso, Leslie Cope, Karen Reddy, Linda M. Resar. HMGA1 induces FGF19 to drive tumor progression and recruit cancer associated fibroblasts in pancreatic adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2414.

Abstract 297: HMGA1 induces FGF-19 to foster tumor-stromal cell crosstalk and drive tumor progression in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors characterized by a dense desmoplastic stroma comprised of cancer associated fibroblasts (CAFs) and fibrotic scar tissue. While stromal CAFs provide a barrier to therapy and release signals that foster tumor growth and invasion, the stroma also restrains tumor growth in murine models. The High Mobility Group A1 (HMGA1) chromatin remodeling gene encodes an oncofetal protein and epigenetic regulator that amplifies signals from the microenvironment to foster stem cell properties within intestinal epithelium. HMGA1 is also highly expressed during embryogenesis and in adult stem cells, but silenced postnatally in most differentiated cells. In diverse, aggressive cancers, HMGA1 becomes aberrantly re-expressed where high levels portend adverse clinical outcomes. In PDAC, HMGA1 protein is detected in late stage precursor lesions and invasive tumors, but not in normal pancreas nor in early precursor lesions. Furthermore, high HMGA1 levels correlate with poor differentiation status and decreased patient survival. Here, we discovered a novel epigenetic program mediated by HMGA1 that recruits CAFs to drive PDAC progression. We discovered that silencing HMGA1 in multiple PDAC cell lines halts proliferation and disrupts oncogenic properties, including migration, invasion, clonogenicity, and xenograft tumorigenesis. HMGA1 silencing also impairs three-dimensional sphere formation and depletes tumor initiator cells in limiting dilution assays. Through RNA sequencing analysis comparing PDAC cells overexpressing HMGA1 to those with HMGA1 silencing, we identified FGF-19 as a potential transcriptional target of HMGA1. HMGA1 binds specifically to the FGF-19 promoter and recruits the active histone mark, H3K4me3, to activate its expression. HMGA1 is also required for FGF-19 secretion from PDAC cells. Similar to HMGA1, silencing FGF-19 blocks oncogenic and cancer stem cell properties in vitro while disrupting tumorigenesis and depleting tumor initiator cells in vivo. In co-culture experiments, HMGA1 expressed in PDAC cells amplifies FGF-19 secretion, thereby stimulating CAF migration to tumor cells across a membrane. Silencing HMGA1 or FGF-19 prevents CAF recruitment to PDAC tumor cells. Furthermore, CAF recruitment is blocked by either FGF-19 blocking antibodies or an inhibitor to the FGF-19 receptor (FGR4). In murine models, silencing HMGA1 also decreases formation of a fibroblastic stroma. Moreover, overexpression of HMGA1 together with that of FGF-19 predict decreased survival in primary human PDAC. Our results reveal a novel paradigm whereby PDAC cells collaborate with stromal CAFs via HMGA1 and FGF-19 to drive tumor progression. These data also provide insight into mechanisms for tumor progression and illuminate FGF-19 as a rational therapeutic target in PDACs with up-regulation of HMGA1 and FGF-19.

Citation Format: Lionel Chia, Shuai Shuai, Lingling Xian, Jung-Hyun Kim, Ruitao Zhang, Tait Huso, David Huso, Leslie Cope, Karen Reddy, Linda Resar. HMGA1 induces FGF-19 to foster tumor-stromal cell crosstalk and drive tumor progression in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 297.

Abstract 4494: HMGA1 drives tumor progression and recruits cancer-associated fibroblasts in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinomas (PDACs) are highly lethal tumors for which there are no effective therapies. Emerging evidence suggests that the tumor stroma interacts with the cancer cells to induce cancer stem cell properties and drive tumor progression. In PDAC, the fibroblast stroma also provides a dense barrier preventing cytotoxic therapy from reaching PDAC cells. We previously discovered that high levels of High Mobility Group A1 (HMGA1) protein predict decreased survival in primary PDAC. Here, we report a novel role for HMGA1-FGF19 in mediating tumor-stromal interactions and tumor progression. Silencing HMGA1 in PDAC cell lines or low-passge, patient-derived cells abruptly halts proliferation. Spindle-shaped, mesenchymal cells became reprogrammed into cuboidal, more epithelial-like cells. Sensitivity to gemcitabine was enhanced and colony formation, migration, invasion, and three-dimensional (3D) sphere formation were all disrupted in cells with HMGA1 knock-down. Silencing HMGA1 also disrupted xenograft tumorigenesis and depleted cancer stem cells/tumor-initiator cells in limiting dilution tumorigenicity assays. To elucidate underlying molecular mechanisms mediating these striking phenotypes, we performed RNA-seq after silencing HMGA1 in invasive, highly metastatic, low-passage patient-derived PDAC cells (10.7). Among the genes regulated by HMGA1 were those encoding proteins involved in tumor-stromal signaling, including the fibroblast growth factor 19 (FGF19). The FGF19 gene is highly expressed in GI tumors (liver, colon, PDAC) and transgenic mice overexpressing Fgr15 (the murine homolog) in hepatocytes develop hepatocellular carcinoma (HCC). FGF19 also correlates with poor outcomes in human HCC and colon cancer, although it's role in PDAC was unknown. Here, we found that FGF19 expression is dependent upon HMGA1 in 3 different PDAC cell lines; silencing HMGA1 represses FGF19 in these cells. HMGA1 also binds directly to the FGF19 promoter at 2 predicted DNA binding sites as assessed by chromatin immunoprecipiation. To determine whether FGF19 plays a functional role in HMGA1-mediated tumor progression and cancer stem cell properties, we silenced FGF19 in PDAC cells. Similar to our results with HMGA1, silencing FGF19 impaired PDAC growth and 3D sphere formation in vitro. Because fibroblast growth factors interact with fibroblasts, we determined whether the HMGA1-FGF19 pathway was involved in tumor cell – stromal crosstalk. PDAC 10.7 cells recruit cancer-associated fibroblasts (CAFs) in a co-culture system, although this recruitment was abrogated when HMGA1 was silenced. CAF migration was also disrupted by anti-human FGF19 neutralizing antibodies. Together, these findings indicate that HMGA1 drive tumor progression and cancer stem cell properties through FGF19 and suggest that targeting the HMGA1-FGF19 pathway maybe efficaceous in PDAC.

Citation Format: Shuai Shuai, Lingling Xian, Tait Huso, Karen Reddy, Linda Resar. HMGA1 drives tumor progression and recruits cancer-associated fibroblasts in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4494.

Abstract 5019: HMGA1 amplifies Wnt signaling and expands the intestinal stem cell compartment to drive premalignant polyposis in transgenic mice

Emerging evidence suggests that cancer cells undergo chromatin remodeling and epigenetic reprogramming to co-opt stem cell properties and drive tumor progression. The HMGA1 chromatin remodeling protein is an architectural transcription factor that binds to DNA at AT-rich sequences where it “opens” chromatin, recruits transcriptional complexes, and modulates gene expression. The HMGA1 gene is highly expressed during embryogenesis and in adult stem cells, but silenced postnatally in differentiated tissues. HMGA1 becomes re-expressed in most high-grade cancers and high levels portend adverse clinical outcomes. In colon cancer, HMGA1 is among the genes most highly overexpressed compared to normal intestinal epithelium. We previously reported that HMGA1 drives tumor progression in colon cancer by inducing stem cell genes involved in an epithelial-mesenchymal transition. We also discovered that Hmga1 transgenic mice develop marked proliferative changes and pre-malignant polyposis in the intestinal epithelium. To determine how Hmga1 functions in the intestines during tissue homeostasis and carcinogenesis, we examined in transgenic mice and organoid models. Here, we uncover a novel role for Hmga1 in maintaining the intestinal stem cell (ISC) pool and Paneth cell niche. Hmga1 is required by ISCs to organize into three-dimensional organoids in vitro; silencing Hmga1 disrupts organoid formation and bud development. Conversely, overexpression of Hmga1 increases organoid formation, bud development, and replating efficiency, suggesting that Hmga1 enhances ISC function and/or number. We therefore crossed the Hmga1 transgenic mice onto the Lgr5-EGFP background to enumerate ISCs and found that Hmga1 expands the ISC compartment. To determine how this occurs, we performed in vivo imaging and discovered that Hmga1 enhances self-renewal of ISCs. Mechanistically, we found that Hmga1 amplifies Wnt/β-catenin signaling by inducing genes encoding both Wnt agonist receptors and downstream Wnt target genes. Surprisingly, Hmga1 also expands the Paneth cell niche, which is comprised of terminally differentiated crypt cells that secrete Wnt to support ISCs. Because Paneth cells require Sox9 for development, we determined whether Hmga1 regulates its expression. Hmga1 binds directly to the Sox9 promoter at 2 AT-rich sites to activate its expression. In human colonic epithelium, HMGA1 and SOX9 are positively correlated, and both become markedly up-regulated in colon carcinogenesis. This work not only provides new insights into the role of Hmga1 in intestinal homeostasis by maintaining both the stem cell pool and epithelial niche compartment, but also suggests that deregulated Hmga1 perturbs this equilibrium during polyposis and carcinogenesis. Our results also highlight the HMGA1-WNT-SOX9 pathway as rational therapeutic target in colon carcinogenesis.

Citation Format: Lingling Xian, Dan Georgess, Li Luo, Lionel Chia, Qihua Gu, Tait Huso, Amy Belton, David Huso, Andrew Ewald, Linda M.S. Resar. HMGA1 amplifies Wnt signaling and expands the intestinal stem cell compartment to drive premalignant polyposis in transgenic mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5019. doi:10.1158/1538-7445.AM2017-5019

HMGA1 amplifies Wnt signalling and expands the intestinal stem cell compartment and Paneth cell niche

High-mobility group A1 (Hmga1) chromatin remodelling proteins are enriched in intestinal stem cells (ISCs), although their function in this setting was unknown. Prior studies showed that Hmga1 drives hyperproliferation, aberrant crypt formation and polyposis in transgenic mice. Here we demonstrate that Hmga1 amplifies Wnt/β-catenin signalling to enhance self-renewal and expand the ISC compartment. Hmga1 upregulates genes encoding both Wnt agonist receptors and downstream Wnt effectors. Hmga1 also helps to 'build' an ISC niche by expanding the Paneth cell compartment and directly inducing Sox9, which is required for Paneth cell differentiation. In human intestine, HMGA1 and SOX9 are positively correlated, and both become upregulated in colorectal cancer. Our results define a unique role for Hmga1 in intestinal homeostasis by maintaining the stem cell pool and fostering terminal differentiation to establish an epithelial stem cell niche. This work also suggests that deregulated Hmga1 perturbs this equilibrium during intestinal carcinogenesis.

The High Mobility Group A1 (HMGA1) Transcriptome in Cancer and Development

BACKGROUND & OBJECTIVES

Chromatin structure is the single most important feature that distinguishes a cancer cell from a normal cell histologically. Chromatin remodeling proteins regulate chromatin structure and high mobility group A (HMGA1) proteins are among the most abundant, nonhistone chromatin remodeling proteins found in cancer cells. These proteins include HMGA1a/HMGA1b isoforms, which result from alternatively spliced mRNA. The HMGA1 gene is overexpressed in cancer and high levels portend a poor prognosis in diverse tumors. HMGA1 is also highly expressed during embryogenesis and postnatally in adult stem cells. Overexpression of HMGA1 drives neoplastic transformation in cultured cells, while inhibiting HMGA1 blocks oncogenic and cancer stem cell properties. Hmga1 transgenic mice succumb to aggressive tumors, demonstrating that dysregulated expression of HMGA1 causes cancer in vivo. HMGA1 is also required for reprogramming somatic cells into induced pluripotent stem cells. HMGA1 proteins function as ancillary transcription factors that bend chromatin and recruit other transcription factors to DNA. They induce oncogenic transformation by activating or repressing specific genes involved in this process and an HMGA1 "transcriptome" is emerging. Although prior studies reveal potent oncogenic properties of HMGA1, we are only beginning to understand the molecular mechanisms through which HMGA1 functions. In this review, we summarize the list of putative downstream transcriptional targets regulated by HMGA1. We also briefly discuss studies linking HMGA1 to Alzheimer's disease and type-2 diabetes.

CONCLUSION

Further elucidation of HMGA1 function should lead to novel therapeutic strategies for cancer and possibly for other diseases associated with aberrant HMGA1 expression.

Fecal Metabolome in Hmga1 Transgenic Mice with Polyposis: Evidence for Potential Screen for Early Detection of Precursor Lesions in Colorectal Cancer

Because colorectal cancer (CRC) remains a leading cause of cancer mortality worldwide, more accessible screening tests are urgently needed to identify early stage lesions. We hypothesized that highly sensitive, metabolic profile analysis of stool samples will identify metabolites associated with early stage lesions and could serve as a noninvasive screening test. We therefore applied traveling wave ion mobility mass spectrometry (TWIMMS) coupled with ultraperformance liquid chromatography (UPLC) to investigate metabolic aberrations in stool samples in a transgenic model of premalignant polyposis aberrantly expressing the gene encoding the high mobility group A (Hmga1) chromatin remodeling protein. Here, we report for the first time that the fecal metabolome of Hmga1 mice is distinct from that of control mice and includes metabolites previously identified in human CRC. Significant alterations were observed in fatty acid metabolites and metabolites associated with bile acids (hypoxanthine xanthine, taurine) in Hmga1 mice compared to controls. Surprisingly, a marked increase in the levels of distinctive short, arginine-enriched, tetra-peptide fragments was observed in the transgenic mice. Together these findings suggest that specific metabolites are associated with Hmga1-induced polyposis and abnormal proliferation in intestinal epithelium. Although further studies are needed, these data provide a compelling rationale to develop fecal metabolomic analysis as a noninvasive screening tool to detect early precursor lesions to CRC in humans.

Abstract 1704: High mobility group A1 chromatin remodeling protein expands the intestinal stem cell compartment and Paneth cell niche through Wnt/β-catenin signaling and Sox9

The High Mobility Group A1 (HMGA1) gene is overexpressed in most poorly differentiated cancers and high levels portend adverse clinical outcomes, although the molecular mechanisms through which it functions are poorly understood. HMGA1 encodes the HMGA1a and HMGA1b chromatin remodeling proteins, which modulate gene expression by bending chromatin and orchestrating the assembly of transcription factor complexes to DNA. HMGA1 is highly expressed during embryogenesis, but silenced in adult, differentiated tissues. Postnatally, HMGA1 expression is maintained in adult stem cells, such as intestinal stem cells (ISCs); however, its role in this setting has been unknown. Here, we report that Hmga1 overexpression in ISCs of transgenic mice drives expansion in the ISC compartment leading to hyperproliferation, aberrant crypt formation, and polyposis. Surprisingly, Hmga1 transgenic mice also exhibit marked expansion in terminally differentiated Paneth cells, which comprise an epithelial cell niche for ISCs. To dissect the mechanisms mediating these phenotypes, we generated three-dimensional (3D) intestinal organoids with varied expression of Hmga1. Strikingly, silencing Hmga1 in wildtype crypt cells disrupts their ability to organize into functional 3D organoids with bud formation, while crypt cells expressing ectopic Hmga1 exhibit enhanced organoid formation with increased ISC number, proliferation, and bud development. Because Wnt/β-catenin signaling is central to ISC function, we determined whether Hmga1 modulates this pathway. β-catenin protein is increased in the crypts of the Hmga1 transgenic mice and organoids. Hmga1 amplifies Wnt/β-catenin signaling by inducing both genes that encode Wnt cell surface receptors and target genes downstream of Wnt/β-catenin. Hmga1 also directly up-regulates Sox9, which is required for terminal differentiation to Paneth cells. This is the first example of Hmga1 fostering terminal differentiation to establish a stem cell niche. In human intestinal epithelium, HMGA1 and SOX9 are highly correlated (P = 0.008), and both become up-regulated in carcinogenesis. These results reveal a novel role for Hmga1 in intestinal homeostasis by maintaining both the stem cell pool and epithelial niche compartment and suggest that deregulated Hmga1 perturbs this equilibrium during intestinal carcinogenesis.

Citation Format: Lingling Xian, Tait Huso, Amy Belton, David Huso, Linda M. S. Resar. High mobility group A1 chromatin remodeling protein expands the intestinal stem cell compartment and Paneth cell niche through Wnt/β-catenin signaling and Sox9. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1704.

The High Mobility Group A1 (HMGA1) gene is highly overexpressed in human uterine serous carcinomas and carcinosarcomas and drives Matrix Metalloproteinase-2 (MMP-2) in a subset of tumors

OBJECTIVES

Although uterine cancer is the fourth most common cause for cancer death in women worldwide, the molecular underpinnings of tumor progression remain poorly understood. The High Mobility Group A1 (HMGA1) gene is overexpressed in aggressive cancers and high levels portend adverse outcomes in diverse tumors. We previously reported that Hmga1a transgenic mice develop uterine tumors with complete penetrance. Because HMGA1 drives tumor progression by inducing MatrixMetalloproteinase (MMP) and other genes involved in invasion, we explored the HMGA1-MMP-2 pathway in uterine cancer.

METHODS

To investigate MMP-2 in uterine tumors driven by HMGA1, we used a genetic approach with mouse models. Next, we assessed HMGA1 and MMP-2 expression in primary human uterine tumors, including low-grade carcinomas (endometrial endometrioid) and more aggressive tumors (endometrial serous carcinomas, uterine carcinosarcomas/malignant mesodermal mixed tumors).

RESULTS

Here, we report for the first time that uterine tumor growth is impaired in Hmga1a transgenic mice crossed on to an Mmp-2 deficient background. In human tumors, we discovered that HMGA1 is highest in aggressive carcinosarcomas and serous carcinomas, with lower levels in the more indolent endometrioid carcinomas. Moreover, HMGA1 and MMP-2 were positively correlated, but only in a subset of carcinosarcomas. HMGA1 also occupies the MMP-2 promoter in human carcinosarcoma cells.

CONCLUSIONS

Together, our studies define a novel HMGA1-MMP-2 pathway involved in a subset of human carcinosarcomas and tumor progression in murine models. Our work also suggests that targeting HMGA1 could be effective adjuvant therapy for more aggressive uterine cancers and provides compelling data for further preclinical studies.

HMGA1 drives metabolic reprogramming of intestinal epithelium during hyperproliferation, polyposis, and colorectal carcinogenesis

Although significant progress has been made in the diagnosis and treatment of colorectal cancer (CRC), it remains a leading cause of cancer death worldwide. Early identification and removal of polyps that may progress to overt CRC is the cornerstone of CRC prevention. Expression of the High Mobility Group A1 (HMGA1) gene is significantly elevated in CRCs as compared with adjacent, nonmalignant tissues. We investigated metabolic aberrations induced by HMGA1 overexpression in small intestinal and colonic epithelium using traveling wave ion mobility mass spectrometry (TWIMMS) in a transgenic model in which murine Hmga1 was misexpressed in colonic epithelium. To determine if these Hmga1-induced metabolic alterations in mice were relevant to human colorectal carcinogenesis, we also investigated tumors from patients with CRC and matched, adjacent, nonmalignant tissues. Multivariate statistical methods and manual comparisons were used to identify metabolites specific to Hmga1 and CRC. Statistical modeling of data revealed distinct metabolic patterns in Hmga1 transgenics and human CRC samples as compared with the control tissues. We discovered that 13 metabolites were specific for Hmga1 in murine intestinal epithelium and also found in human CRC. Several of these metabolites function in fatty acid metabolism and membrane composition. Although further validation is needed, our results suggest that high levels of HMGA1 protein drive metabolic alterations that contribute to CRC pathogenesis through fatty acid synthesis. These metabolites could serve as potential biomarkers or therapeutic targets.

The HMGA1-COX-2 axis: a key molecular pathway and potential target in pancreatic adenocarcinoma

CONTEXT

Although pancreatic cancer is a common, highly lethal malignancy, the molecular events that enable precursor lesions to become invasive carcinoma remain unclear. We previously reported that the high-mobility group A1 (HMGA1) protein is overexpressed in >90% of primary pancreatic cancers, with absent or low levels in early precursor lesions.

METHODS

Here, we investigate the role of HMGA1 in reprogramming pancreatic epithelium into invasive cancer cells. We assessed oncogenic properties induced by HMGA1 in non-transformed pancreatic epithelial cells expressing activated K-RAS. We also explored the HMGA1-cyclooxygenase (COX-2) pathway in human pancreatic cancer cells and the therapeutic effects of COX-2 inhibitors in xenograft tumorigenesis.

RESULTS

HMGA1 cooperates with activated K-RAS to induce migration, invasion, and anchorage-independent cell growth in a cell line derived from normal human pancreatic epithelium. Moreover, HMGA1 and COX-2 expression are positively correlated in pancreatic cancer cell lines (r(2) = 0.93; p < 0.001). HMGA1 binds directly to the COX-2 promoter at an AT-rich region in vivo in three pancreatic cancer cell lines. In addition, HMGA1 induces COX-2 expression in pancreatic epithelial cells, while knock-down of HMGA1 results in repression of COX-2 in pancreatic cancer cells. Strikingly, we also discovered that Sulindac (a COX-1/COX-2 inhibitor) or Celecoxib (a more specific COX-2 inhibitor) block xenograft tumorigenesis from pancreatic cancer cells expressing high levels of HMGA1.

CONCLUSIONS

Our studies identify for the first time an important role for the HMGA1-COX-2 pathway in pancreatic cancer and suggest that targeting this pathway could be effective to treat, or even prevent, pancreatic cancer.