Browsing by Subject "KRAS"

Now showing 1 - 4 of 4
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    Beyond Kras: MYC Rules in Pancreatic Cancer
    (Elsevier, 2018-05-26) Korc, Murray; Medicine, School of Medicine
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    Loss of TIP30 Accelerates Pancreatic Cancer Progression and Metastasis
    (2019-07) Imasuen Williams, Imade E.; Hurley, Thomas; Harrington, Maureen; Herbert, Brittney-Shea; Nakshatri, Harikrishna
    Pancreatic ductal adenocarcinoma (PDAC) is currently the fourth leading cause of cancer-related death in the United States, and is characterized by key driver mutations (e.g. KRAS, TP53, CDKN2A, and SMAD4), elevated expression of growth factors such as TGF-βs and the EGF receptor (EGFR), a markedly desmoplastic stroma, and a propensity to develop multi-organ metastases and chemoresistance. Consistent with its aggressive nature, the 5-year survival rate for PDAC is 8-9%, which demonstrates an urgent need to develop novel therapies. High expression levels of microRNA-10b (miR-10b) in PDAC tissues are associated with decreased patient survival and earlier appearance of metastatic disease following neoadjuvant chemoradiotherapy. miR-10b downregulates the expression of transcription coactivator Tat-Interacting Protein 30 (TIP30) by targeting its 3’UTR. TIP30 has multiple reported functions. TIP30 suppresses tumor formation and metastasis, forms a complex that regulates EGFR trafficking and degradation, and transcriptionally upregulates pro-apoptotic genes. Alterations in TIP30 have been reported in multiple human cancers, including pancreatic cancer. We hypothesized that Tip30-deficiency accelerates PDAC progression and metastasis in a murine model of PDAC. To test this hypothesis, we crossed mice with oncogenic Kras (KC) localized to the pancreas epithelium, with Tip30-deficient mice (K30C). We compared PDAC histopathology between Tip30-heterozygous (K30+/-C) and Tip30-null (K30-/-C) mice. Tip30-heterozygosity accelerated PDAC-lesion-associated pancreatic cancer cell (PCC) pulmonary seeding. By contrast, total loss of Tip30 enhanced PCC micrometastatic seeding to the liver and hepatic metastasis. K30+/-C mice also presented with an early, increased penetrance of lung lesions and lung adenocarcinoma; and PCCs isolated from K30+/-C pancreata exhibited increased EGFR protein levels. These findings suggest that TIP30 deficiency can have a dose-dependent effect on organotropic metastasis and EGFR levels in PCCs. Future studies will delineate the molecular consequences of TIP30 loss in PDAC and contribute to a broader understanding of pancreatic cancer metastasis.
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    Outcomes of patients with stage III non-small cell lung cancer (NSCLC) that harbor a STK11 mutation
    (AME, 2021) An, Josiah; Yan, Melissa; Yu, Nanmeng; Chennamadhavuni, Adithya; Furqan, Muhammad; Mott, Sarah L.; Loeffler, Bradley T.; Kruser, Timothy; Sita, Timothy L.; Feldman, Lawrence; Nguyen, Ryan; Pasquinelli, Mary; Hanna, Nasser H.; Hejleh, Taher Abu; Medicine, School of Medicine
    Background: STK11 mutation (STK11m ) in patients (pts) with stage IV non-small cell lung cancer (NSCLC) is associated with inferior survival and poor response to immune checkpoint inhibitors (ICI). The significance of STK11m in stage III NSCLC pts treated with concurrent chemoradiation (CCRT) with or without consolidation ICI is unknown. Methods: Stage III NSCLC patients who received CCRT and had known STK11 mutational status were included in this retrospective study. The data on the STK11m pts were collected from 4 cancer institutions. A cohort of pts with wild type STK11 (STK11w ) from the University of Iowa served as a comparison group. Patient demographics and clinical characteristics were collected. Cox regression models were used to explore the effect of STK11 mutation on survival. Results: 75 pts with stage III NSCLC who had known STK11 mutational status were identified. 16/75 (21%) had STK11m . 5/16 with STK11 m did not receive CCRT so they were excluded from the analysis. The clinical and demographic characteristics for the 11 STK11m and 59 STK11w pts were not statistically different (STK11m vs. STK11w ): mean age: 57 vs. 64 yrs, non-squamous histology: 8/11 (73%) vs. 37/59 (63%), KRAS mutation: 3/11 (27%) vs. 11/59 (19%), TP53 mutation: 6/11 (55%) vs. 15/59 (25%), PD-L1 ≥50%: 1/8 (13%) vs. 10/32 (31%), and consolidation ICI 6/11 (55%) vs. 17/59 (29%). Regarding the 6 STK11m pts who received ICI (4 pembrolizumab, 2 durvalumab), the median number of ICI infusions was 8 (range, 3-17) vs. 6 (range, 1-25) in the 17 pts with STK11w who received ICI (durvalumab). After adjusting for performance status and cancer stage, multivariable analysis showed that progression free survival (PFS) for the STK11m pts was significantly worse than STK11 w pts (HR =2.25; 95% CI, 1.03-4.88, P=0.04), whereas overall survival (OS) showed no significant difference for STK11m vs. STK11w patients (HR 1.47, 95% CI, 0.49-4.38, P=0.49). Conclusions: In stage III NSCLC patients who received CCRT, STK11m was associated with worse PFS compared to STK11w . Larger studies are needed to further explore the prognostic implications of STK11m in stage III NSCLC and whether ICI impacts survival for this subgroup.
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    Targeting KRAS for the potential treatment of pancreatic ductal adenocarcinoma: Recent advancements provide hope (Review)
    (Spandidos, 2023-10-04) Zhang, Joshua; Darman , Lily; Hassan , Md Sazzad; Holzen , Urs Von; Awasthi, Niranjan; Medicine, School of Medicine
    Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most frequently mutated oncogenes in solid tumors. More than 90% of pancreatic ductal adenocarcinoma (PDAC) are driven by mutations in the KRAS gene, suggesting the importance of targeting this oncogene in PDAC. Initial efforts to target KRAS have been unsuccessful due to its small size, high affinity for guanosine triphosphate/guanosine diphosphate, and lack of distinct drug‑binding pockets. Therefore, much of the focus has been directed at inhibiting the activation of major signaling pathways downstream of KRAS, most notably the PI3K/AKT and RAF/MAPK pathways, using tyrosine kinase inhibitors and monoclonal antibodies. While preclinical studies showed promising results, clinical data using the inhibitors alone and in combination with other standard therapies have shown limited practicality, largely due to the lack of efficacy and dose‑limiting toxicities. Recent therapeutic approaches for KRAS‑driven tumors focus on mutation‑specific drugs such as selective KRASG12C inhibitors and son of sevenless 1 pan‑KRAS inhibitors. While KRASG12C inhibitors showed great promise against patients with non‑small cell lung cancer (NSCLC) harboring KRASG12C mutations, they were not efficacious in PDAC largely because the major KRAS mutant isoforms in PDAC are G12D, G12V, and G12R. As a result, KRASG12D and pan‑KRAS inhibitors are currently under investigation as potential therapeutic options for PDAC. The present review summarized the importance of KRAS oncogenic signaling, challenges in its targeting, and preclinical and clinical targeted agents including recent direct KRAS inhibitors for blocking KRAS signaling in PDAC.