Deficient DNA mismatch repair (dMMR) induces a hypermutator phenotype that can lead to tumorigenesis; however, the functional impact of the high mutation burden resulting from this phenotype remains poorly explored. Here, we demonstrate that dMMR-induced destabilizing mutations lead to proteome instability in dMMR tumors, resulting in an abundance of misfolded protein aggregates. To compensate, dMMR cells utilize a Nedd8-mediated degradation pathway to facilitate clearance of misfolded proteins.
View Article and Find Full Text PDFMouse models of gastroesophageal junction (GEJ) cancer strive to recapitulate the intratumoral heterogeneity and cellular crosstalk within patient tumors to improve clinical translation. GEJ cancers remain a therapeutic challenge due to the lack of a reliable mouse model for preclinical drug testing. In this study, a novel patient-derived orthotopic xenograft (PDOX) was established from GEJ cancer via transabdominal surgical implantation.
View Article and Find Full Text PDFCyclin-dependent kinase 9 (CDK9) transcriptionally regulates several proteins and cellular pathways central to radiation induced tissue injury. We investigated a role of BAY1143572, a new highly specific CDK9 inhibitor, as a sensitizer to radiation in esophageal adenocarcinoma. synergy between the CDK9 inhibitor and radiation was evaluated by clonogenic assay.
View Article and Find Full Text PDFVesicular acidification and trafficking are associated with various cellular processes. However, their pathologic relevance to cancer remains elusive. We identified transmembrane protein 9 (TMEM9) as a vesicular acidification regulator.
View Article and Find Full Text PDFPurpose: Though the efficacy of MEK inhibitors is being investigated in KRAS-mutant colorectal cancers (CRC), early clinical trials of MEK inhibitor monotherapy did not reveal significant antitumor activity. Resistance to MEK inhibitor monotherapy developed through a variety of mechanisms converging in ERK reactivation. Since ERK increases cyclin D expression and increases entry into the cell cycle, we hypothesized that the combination of MEK inhibitors and CDK4/6 inhibitors would have synergistic antitumor activity and cause tumor regression in vivo.
View Article and Find Full Text PDFHypobaric treatment is becoming a potential technology to protect fruits from postharvest decay. The objective of this study was to investigate the effects of hypobaric treatments on storage quality, bioactive compounds, and antioxidant activity of tomato fruit. In this study, green tomatoes (cv.
View Article and Find Full Text PDFIn chronic lymphocytic leukemia (CLL), the increment in PBLs is slower than the expected increment calculated from the cells' proliferation rate, suggesting that cellular proliferation and apoptosis are concurrent. Exploring this phenomenon, we found overexpression of caspase-3, higher cleaved poly (ADP-ribose) polymerase levels (p < 0.007), and a higher apoptosis rate in cells from patients with high counts compared with cells from patients with low counts.
View Article and Find Full Text PDFTiming of flowering is not only an interesting topic in developmental biology, but it also plays a significant role in agriculture for its effects on the maturation time of seed. The hexaploid wheat (Triticum aestivum) is one of the most important crop species whose flowering time, i.e.
View Article and Find Full Text PDFUnlabelled: While reviewing chronic lymphocytic leukemia (CLL) bone marrow slides, we identified cytoplasmic lipid vacuoles in CLL cells but not in normal B cells. Because lipoprotein lipase (LPL), which catalyzes hydrolysis of triglycerides into free fatty acids (FFA), is aberrantly expressed in CLL, we investigated whether LPL regulates the oxidative metabolic capacity of CLL cells. We found that unlike normal B cells, CLL cells metabolize FFAs.
View Article and Find Full Text PDFIn chronic lymphocytic leukemia (CLL), stimulation of the B-cell receptor (BCR) triggers survival signals. Because in various cells activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway provides cells with survival advantage, we wondered whether BCR stimulation activates the JAK/STAT pathway in CLL cells. To stimulate the BCR we incubated CLL cells with anti-IgM antibodies.
View Article and Find Full Text PDFCurcumin (diferuloylmethane) is a potent anti-inflammatory and anti-tumorigenic agent that has shown preclinical activity in diverse cancers. Curcumin up-regulates heat shock protein 70 (hsp70) mRNA in several different cancer cell lines. Hsp70 contributes to an escape from the apoptotic effects of curcumin by several different mechanisms including prevention of the release of apoptosis inducing factor from the mitochondria and inhibition of caspases 3 and 9.
View Article and Find Full Text PDFNeurofibromatosis type 2 (NF2) is a genetic condition characterized by inactivation of the NF2 tumor suppressor gene and the development of schwannomas. The NF2 gene product, merlin, is activated (dephosphorylated) by contact inhibition and promotes growth suppression. We investigated the effect of curcumin (diferuloylmethane), a molecule with anti-inflammatory and antitumorigenic properties, on human schwannoma cell growth and the regulation of merlin by curcumin in both NF2 cells and neuroblastoma (non-NF2) cells.
View Article and Find Full Text PDFThe purpose of this study was to determine whether the Bcr-Abl tyrosine kinase can be assessed by gamma-imaging using an 111In-labeled anti-phosphotyrosine (APT) antibody, and if the response to treatment with imatinib could be detected using this imaging technique. APT antibody was labeled with 111In using ethylenedicysteine (EC) as a chelator. To determine if 111In-EC-APT could assess a nonreceptor tyrosine kinase, xenografts of the human chronic myelogenous leukemia cell line K562 were used.
View Article and Find Full Text PDFImatinib mesylate (IM) binds to the BCR-ABL protein, inhibiting its kinase activity and effectively controlling diseases driven by this kinase. IM resistance has been associated with kinase mutations or increased BCR-ABL expression. However, disease progression may be mediated by other mechanisms that render tumor cells independent of BCR-ABL.
View Article and Find Full Text PDFClinical studies have shown that the tyrosine kinase inhibitor STI571 effectively controls BCR-ABL-positive chronic myelogenous leukemia (CML). However, disease progression while on STI571 therapy has been reported, suggesting de novo or intrinsic resistance to BCR-ABL-targeted therapy. To investigate possible mediators of acquired STI571 resistance, K562 cells resistant to 5 microM STI571 (K562-R) were cloned and compared to the parental cell population.
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