Carcinogenesis最新文献

BRAF V600E, one of the most frequent mutations in the MAPK pathway, confers poor prognosis to colorectal cancers (CRCs), partly because of chemotherapeutic resistance. Oncogene-induced DNA damage responses (DDRs) that primarily activate p53 are important mechanistic barriers to the malignant transformation of cells; however, the mechanism underlying this impairment in cancer remains unknown. Here, we evaluated the responses of BRAFV600E-induced DDRs in two CRC cell lines, SW48 and LIM1215, both of which harbor wild-type TP53, KRAS, and BRAF. BRAFV600E transduction exhibited distinct phenotypes in these cells: SW48 cell proliferation markedly decreased, whereas that of LIM1215 increased. BRAFV600E expression induced the activation of oncogene-induced DDR signaling in SW48 cells, but not in LIM1215 cells, whereas chemotherapeutic agents similarly activated DDRs in both cell lines. Knockdown experiments revealed that these responses in SW48 cells were mediated by p53-p21 pathway activation. Comet assay (both alkaline and neutral) revealed that BRAFV600E increased single-strand breaks to the same extent in both cell lines; however, in the case of LIM1215 cells, it only facilitated double-strand breaks. Furthermore, the proliferation of LIM1215 cells, wherein no oncogene-induced DDRs occurred, was synergistically inhibited upon MDM2 inhibitor-mediated p53 activation combined with MEK inhibition. Taken together, these distinct DDR signaling responses highlight the novel characteristics of BRAFV600E-mutated CRC cells and define the therapeutic potential of p53 activation combined with MAPK inhibition against TP53 wild-type CRC harboring a BRAFV600E mutation.

Ultra-low-pass whole-genome sequencing (ULP-WGS) (≤0.5× coverage) of plasma cell-free DNA (cfDNA) has emerged as a low-cost promising tool to assess circulating tumor DNA (ctDNA) fraction. This meta-analysis aims to summarize the current findings and comprehensively investigate the prognostic value of baseline ctDNA detected by ULP-WGS in solid tumors. A systematic review was carried out by searching PubMed/MEDLINE and Scopus databases to identify eligible studies conducted between January 2014 and January 2024. Inclusion criteria comprised studies with reported overall survival (OS) and progression-free survival (PFS) outcomes across therapy-naïve patients with different solid tumors. All patients underwent baseline ULP-WGS of plasma cfDNA and were categorized as ctDNA positive (tumor fraction ≥10%) or negative (tumor fraction <10%). A one-stage meta-analysis was performed using patient-level survival data reconstructed from published articles. A Cox proportional hazards model with shared frailty was used to assess the difference in survival between arms. A total of six studies, comprising 620 patients (367 negative ctDNA and 253 positive ctDNA), were included in the OS analysis, while five studies, involving 349 patients (212 negative ctDNA and 137 positive ctDNA), were included in the PFS analysis. The meta-analysis showed that patients with baseline positive ctDNA had a significantly higher risk of death (HR = 2.60, 95% CI: 2.01-3.36) and disease progression (HR = 2.28, 95% CI: 1.71-3.05) compared to those with negative ctDNA. The presence of a positive ctDNA at baseline is associated with increased risk of death and progression in patients with same stage cancer.

New-onset diabetes (NOD) is a common condition among patients with pancreatic adenocarcinoma (PAAD) and is related to poor clinical outcomes. The potential impact of NOD on PAAD progression and the tumor microenvironment remains unclear. Here, we revealed that NOD in PAAD was associated with metabolic disorders. Utilizing three machine learning algorithms, a new-onset diabetes-related metabolism signature (NRMS) was established. Validated in three independent cohorts, patients with a high NRMS score exhibited worse prognosis. Moreover, an elevated NRMS score was associated with an immunosuppressive microenvironment and diminished response to immunotherapy. Further experiments demonstrated that ALDH3A1, a key feature in NRMS, was significantly up-regulated in tissues from PAAD patients with NOD and played a crucial role in tumor progression and immune suppression. Our findings highlight the potential of NRMS as a prognostic biomarker and an indicator of immunotherapy response for patients with PAAD.

Phospholipase D (PLD) plays a critical role in cancer progression. However, its role in pancreatic cancer remains unclear. Thus, we evaluated the role of PLD1, one of two classical isoforms of PLD, in pancreatic carcinogenesis in vivo. The role of PLD1 in tumor growth was evaluated by subcutaneously transplanting human MIA PaCa-2 cells expressing endogenous PLD1 levels (Ctr KD cells) or cells in which PLD1 was knocked down (Pld1 KD cells) into immunodeficient mice. Twenty days post-implantation, tumors that arose from Pld1-KD cells were significantly smaller, compared to controls (Ctr KD). Then, we assessed the role of PLD1 in the tumor microenvironment, by subcutaneously implanting mouse LSL-KrasG12D/+;Trp53R172H/+;Pdx-1-Cre (KPC) cells into wild-type (WT) or PLD1 knockout (Pld1-/-) mice. Compared to WT, tumor growth was attenuated in Pld1-/- mice by 39%, whereas treatment of Pld1-/- mice with gemcitabine reduced tumor growth by 79%. When PLD1 was ablated in LSL-KrasG12D;Ptf1Cre/+ (KC) mice, no reduction in acinar cell loss was observed, compared to KC mice. Finally, treatment of KC mice with a small molecule inhibitor of PLD1 and PLD2 (FIPI) significantly reduced acinar cell loss and cell proliferation, compared to vehicle-treated mice. Mechanistically, the effect of PLD on tumor growth is mediated, partly, by the FAK pathway. In conclusion, while PLD1 is a critical regulator of pancreatic xenograft and allograft growth, playing an important role at the tumor and at the microenvironment levels, inhibition of PLD1 and PLD2 are necessary to reduce pancreatic carcinogenesis in KC mice, and might represent a novel therapeutic target.

Cancer cells exhibit heterogeneous metastatic potential, and high metastatic (HM) subclones can enhance the metastatic potential of low metastatic subclones by transmitting some factors. Exosomal miRNAs play a pivotal role in the crosstalk of heterogeneous metastatic subclones. This study discovered that miR-20a-3p was upregulated in colorectal adenocarcinoma (CRA), correlated with metastasis, and potentially served as a prognostic indicator for CRA. miR-20a-3p could promote the proliferation, migration, and invasion of CRA cells. Interestingly, HM CRA cells could promote malignant phenotypes of low metastatic CRA cells by transmitting exosomal miR-20a-3p. Mechanically, miR-20a-3p could inhibit neurofibromin 1(NF1), thereby activate the rat sarcoma viral oncogene (RAS)-mediated mitogen-activated protein kinases (MAPK) signaling pathway to drive the metastasis of CRA. In summary, our study provided evidence that colorectal cancer cells with HM potential drive metastasis by transmitting exosomal miR-20a-3p through modulating the NF1/MAPK pathway.

Nucleotide metabolism is the ultimate and most critical link in the self-replication process of tumors, including gastric cancer (GC). However, in clinical treatment, classic antitumor drugs such as 5-fluorouracil (5-FU) are mostly metabolic analogs of purines or pyrimidines, which lack specificity for tumor cells and therefore have significant side effects. It is unclear whether there are other drugs that can target nucleotide metabolism, except for nucleic acid analogs. Here, we found that a natural compound, dehydroabietylamine (DHAA), significantly reduced the viability and proliferation of GC cells and organoids. DHAA disrupts the purine and pyrimidine metabolism of GC cells, causing DNA damage and further inducing apoptosis. DHAA treatment decreased transcription and protein levels of key enzymes involved in the nucleotide metabolism pathway, with significant reductions in the expression of pyrimidine metabolism key enzymes CAD, DHODH, and purine metabolism key enzymes PAICS. We also found that DHAA directly binds to and reduces the expression of Forkhead box K2 (FOXK2), a common transcription factor for these metabolic enzymes. Ultimately, DHAA was shown to delay tumorigenesis in K19-Wnt1/C2mE transgenic mice model and reduce levels of CAD, DHODH, and PAICS in vivo. We demonstrate that DHAA exerts an anticancer effect on GC by targeting transcription factor FOXK2, reducing transcription of key genes for nucleotide metabolism and impairing nucleotide biosynthesis, thus DHAA is a promising candidate for GC therapy.

Merriam-Webster and Oxford define a xenobiotic as any substance foreign to living systems. Allura Red AC (a.k.a., E129; FD&C Red No. 40), a synthetic food dye extensively used in manufacturing ultra-processed foods and therefore highly prevalent in our food supply, falls under this category. The surge in synthetic food dye consumption during the 70s and 80s was followed by an epidemic of metabolic diseases and the emergence of early-onset colorectal cancer in the 1990s. This temporal association raises significant concerns, particularly given the widespread inclusion of synthetic food dyes in ultra-processed products, notably those marketed toward children. Given its interactions with key contributors to colorectal carcinogenesis such as inflammatory mediators, the microbiome, and DNA damage, there is growing interest in understanding Allura Red AC's potential impact on colon health as a putative carcinogen. This review discusses the history of Allura Red AC, current research on its effects on the colon and rectum, potential mechanisms underlying its impact on colon health, and provides future considerations. Indeed, although no governing agencies classify Allura Red AC as a carcinogen, its interaction with key guardians of carcinogenesis makes it suspect and worthy of further molecular investigation. The goal of this review is to inspire research into the impact of synthetic food dyes on colon health.

Osteosarcoma (OS) is a bone malignant tumor affecting children, adolescents, and young adults. Currently, osteosarcoma is treated with chemotherapy regimens established over 40 years ago. The investigation of novel therapeutic strategies for the treatment of osteosarcoma remains an important clinical need. Cyclin-dependent kinases (CDKs) have been considered promising molecular targets in cancer therapy. Among these, CDK12 has been shown to play a crucial role in the pathogenesis of malignancies, but its clinical significance and biological mechanisms in osteosarcoma remain unclear. In the present study, we aim to determine the expression and function of CDK12 and evaluate its prognostic and therapeutic value in metastatic osteosarcoma. We found that overexpression of CDK12 was associated with high tumor grade, tumor progression and reduced patient survival. The underlying mechanism revealed that knockdown of CDK12 expression with small interfering RNA or functional inhibition with the CDK12-targeting agent THZ531 effectively exhibited time- and dose-dependent cytotoxicity. Downregulation of CDK12 paused transcription by reducing RNAP II phosphorylation, interfered with DNA damage repair with increased γH2AX, and decreased cell proliferation through the PI3K-AKT pathway. This was accompanied by the promotion of apoptosis, as evidenced by enhanced Bax expression and reduced Bcl-xL expression. Furthermore, the CDK12 selective inhibitor THZ531 also hindered ex vivo 3D spheroid formation, growth of in vitro 2D cell colony, and prevented cell mobility. Our findings highlight the clinical importance of CDK12 as a potentially valuable prognostic biomarker and therapeutic target in metastatic osteosarcoma.

High circulating vitamin D levels and supplementation may lower prostate cancer mortality. To probe for direct effects of vitamin D signaling in the primary tumor, we assessed how activation of intratumoral vitamin D signaling in prostate cancer is associated with lethal prostate cancer during long-term follow-up. Among 404 participants with primary prostate cancer in the Health Professionals Follow-up Study and the Physicians' Health Study, we defined a gene score of expected activated intratumoral vitamin D signaling consisting of transcriptionally upregulated (CYP27A1, CYP2R1, RXRA, RXRB, and VDR) and downregulated genes (CYP24A1 and DHCR7). We contrasted vitamin D signaling in tumors that progressed to lethal disease (metastases/prostate cancer-specific death, n = 119) over up to three decades of follow-up with indolent tumors that remained nonmetastatic for >8 years post-diagnosis (n = 285). The gene score was downregulated in tumor tissue compared with tumor-adjacent histologically normal tissue of the same men. Higher vitamin D gene scores were inversely associated with lethal prostate cancer (odds ratio for highest versus lowest quartile: 0.46, 95% confidence interval: 0.21-0.99) in a dose-response fashion and after adjusting for clinical and pathologic factors. This association appeared strongest among men with high predicted plasma 25-hydroxyvitamin D3 and men with body mass index ≥25 kg/m2. Findings were replicated with broader gene sets. These data support the hypothesis that active intratumoral vitamin D signaling is associated with better prostate cancer outcomes and provide further rationale for testing how vitamin D-related interventions after diagnosis could improve prostate cancer survival through effects on the tumor.