Bacterial Metabolism Affects the C. elegans Response to Cancer Chemotherapeutics.

The human microbiota greatly affects physiology and disease; however, the contribution of bacteria to the response to chemotherapeutic drugs remains poorly understood. Caenorhabditis elegans and its bacterial diet provide a powerful system to study host-bacteria interactions. Here, we use this system to study how bacteria affect the C. elegans response to chemotherapeutics. We find that different bacterial species can increase the response to one drug yet decrease the effect of another. We perform genetic screens in two bacterial species using three chemotherapeutic drugs: 5-fluorouracil (5-FU), 5-fluoro-2'-deoxyuridine (FUDR), and camptothecin (CPT). We find numerous bacterial nucleotide metabolism genes that affect drug efficacy in C. elegans. Surprisingly, we find that 5-FU and FUDR act through bacterial ribonucleotide metabolism to elicit their cytotoxic effects in C. elegans rather than by thymineless death or DNA damage. Our study provides a blueprint for characterizing the role of bacteria in the host response to chemotherapeutics.

Host-Microbe Co-metabolism Dictates Cancer Drug Efficacy in C. elegans.

Fluoropyrimidines are the first-line treatment for colorectal cancer, but their efficacy is highly variable between patients. We queried whether gut microbes, a known source of inter-individual variability, impacted drug efficacy. Combining two tractable genetic models, the bacterium E. coli and the nematode C. elegans, we performed three-way high-throughput screens that unraveled the complexity underlying host-microbe-drug interactions. We report that microbes can bolster or suppress the effects of fluoropyrimidines through metabolic drug interconversion involving bacterial vitamin B6, B9, and ribonucleotide metabolism. Also, disturbances in bacterial deoxynucleotide pools amplify 5-FU-induced autophagy and cell death in host cells, an effect regulated by the nucleoside diphosphate kinase ndk-1. Our data suggest a two-way bacterial mediation of fluoropyrimidine effects on host metabolism, which contributes to drug efficacy. These findings highlight the potential therapeutic power of manipulating intestinal microbiota to ensure host metabolic health and treat disease.

5-Fluorouracil efficacy requires anti-tumor immunity triggered by cancer-cell-intrinsic STING.

5-Fluorouracil (5-FU) is a widely used chemotherapeutic drug, but the mechanisms underlying 5-FU efficacy in immunocompetent hosts in vivo remain largely elusive. Through modeling 5-FU response of murine colon and melanoma tumors, we report that effective reduction of tumor burden by 5-FU is dependent on anti-tumor immunity triggered by the activation of cancer-cell-intrinsic STING. While the loss of STING does not induce 5-FU resistance in vitro, effective 5-FU responsiveness in vivo requires cancer-cell-intrinsic cGAS, STING, and subsequent type I interferon (IFN) production, as well as IFN-sensing by bone-marrow-derived cells. In the absence of cancer-cell-intrinsic STING, a much higher dose of 5-FU is needed to reduce tumor burden. 5-FU treatment leads to increased intratumoral T cells, and T-cell depletion significantly reduces the efficacy of 5-FU in vivo. In human colorectal specimens, higher STING expression is associated with better survival and responsiveness to chemotherapy. Our results support a model in which 5-FU triggers cancer-cell-initiated anti-tumor immunity to reduce tumor burden, and our findings could be harnessed to improve therapeutic effectiveness and toxicity for colon and other cancers.

Dihydropyrimidine Dehydrogenase Polymorphism c.2194G>A Screening Is a Useful Tool for Decreasing Gastrointestinal and Hematological Adverse Drug Reaction Risk in Fluoropyrimidine-Treated Patients.

Although the risk of fluoropyrimidine toxicity may be decreased by identifying poor metabolizers with a preemptive dihydropyrimidine dehydrogenase (DPYD) test, following international standards, many patients with wild-type (WT) genotypes for classic variations may still exhibit adverse drug reactions (ADRs). Therefore, the safety of fluoropyrimidine therapy could be improved by identifying new DPYD polymorphisms associated with ADRs. This study was carried out to assess whether testing for the underestimated c.2194G>A (DPYD*6 polymorphism, rs1801160) is useful, in addition to other well-known variants, in reducing the risk of ADRs in patients undergoing chemotherapy treatment. This retrospective study included 132 patients treated with fluoropyrimidine-containing regimens who experienced ADRs such as gastrointestinal, dermatological, hematological, and neurological. All subjects were screened for DPYD variants DPYD2A (IVS14+1G>A, c.1905+1G>A, rs3918290), DPYD13 (c.1679T>G, rs55886062), c.2846A>T (rs67376798), c.1236G>A (rs56038477), and c.2194G>A by real-time polymerase chain reaction (RT-PCR). In this cohort, the heterozygous c.2194G>A variant was present in 26 patients, while 106 individuals were WT; both subgroups were compared for the incidence of ADRs. This assessment revealed a high incidence of gastrointestinal and hematological ADRs in DPYD6 carriers compared to WT. Moreover, we have shown a higher prevalence of ADRs in females compared to males when stratifying c.2194G>A carrier individuals. Considering that c.2194G>A was linked to clinically relevant ADRs, we suggest that this variant should also be assessed preventively to reduce the risk of fluoropyrimidine-related ADRs.

The combination of SHP099 inhibits the malignant biological behavior of L-OHP/5-FU-resistant colorectal cancer cells by regulating energy metabolism reprogramming.

BACKGROUND AND OBJECTIVE: Colorectal cancer (CRC) is one of the most common malignancies in China. At present, there is a problem that the CRC treatment drugs SHP099, L-OHP and 5-FU are insensitive to tumor cells. Combination medication is an important means to solve the insensitivity of medication alone. The purpose of this project was to explore the effect and molecular mechanism of SHP099 combination on the malignant biological behavior of L-OHP/5-FU resistant strains of CRC. METHODS: HT29 and SW480 cells were cultured in media supplemented with L-OHP or 5-FU to establish drug-resistant strains. HT29 and SW480 drug-resistant cells were subcutaneously injected into the ventral nerves of nude mice at a dose of 5 × 106 to establish CRC drug-resistant animal models. CCK-8, Western blot, flow cytometry, Transwell and kit detection were used to detect the regulatory mechanism of energy metabolism reprogramming in drug-resistant CRC cells. RESULTS: Compared with nonresistant strains, L-OHP/5-FU-resistant strains exhibited greater metabolic reprogramming. Functionally, SHP099 can restrain the metabolic reprogramming of L-OHP/5-FU-resistant strains and subsequently restrain the proliferation, colony formation, migration and spheroid formation of L-OHP/5-FU-resistant strains. Downstream mechanistic studies have shown that SHP099 interferes with the metabolic reprogramming of L-OHP/5-FU drug-resistant strains by suppressing the PI3K/AKT pathway, thereby restraining the malignant biological behavior of L-OHP/5-FU drug-resistant strains and alleviating CRC. CONCLUSION: The combination of SHP099 can restrain the malignant biological behavior of L-OHP/5-FU-resistant CRC cells and alleviate the progression of CRC by interfering with the reprogramming of energy metabolism. This study explored the effect of SHP099 combination on dual-resistant CRC cells for the first time, and provided a new therapeutic idea for solving the problem of SHP099 insensitivity to CRC cells.

The FOXO1/G6PC axis promotes gastric cancer progression and mediates 5-fluorouracil resistance by targeting the PI3K/AKT/mTOR signaling pathway.

Gastric cancer (GC) is a prevalent malignancy of the digestive system. Distant metastasis and chemotherapy resistance are the crucial obstacles to prognosis in GC. Recent research has discovered that the glucose-6-phosphatase catalytic subunit (G6PC) plays an important role in tumor malignant development. However, little evidence has highlighted its role in GC. Herein, through a comprehensive analysis including profiling of tissue samples and functional validation in vivo and in vitro, we identify G6PC as a crucial factor in GC tumorigenesis. Importantly, we found that the FOXO1/G6PC axis could accelerate GC cell proliferation, metastasis, and 5-Fluorouracil (5-FU) resistance by targeting the PI3K/AKT/mTOR signaling pathway, implicating that as a prospective therapeutic approach in GC.

Bacterial DnaK reduces the activity of anti-cancer drugs cisplatin and 5FU.

BACKGROUND: Chemotherapy is a primary treatment for cancer, but its efficacy is often limited by cancer-associated bacteria (CAB) that impair tumor suppressor functions. Our previous research found that Mycoplasma fermentans DnaK, a chaperone protein, impairs p53 activities, which are essential for most anti-cancer chemotherapeutic responses. METHODS: To investigate the role of DnaK in chemotherapy, we treated cancer cell lines with M. fermentans DnaK and then with commonly used p53-dependent anti-cancer drugs (cisplatin and 5FU). We evaluated the cells' survival in the presence or absence of a DnaK-binding peptide (ARV-1502). We also validated our findings using primary tumor cells from a novel DnaK knock-in mouse model. To provide a broader context for the clinical significance of these findings, we investigated human primary cancer sequencing datasets from The Cancer Genome Atlas (TCGA). We identified F. nucleatum as a CAB carrying DnaK with an amino acid composition highly similar to M. fermentans DnaK. Therefore, we investigated the effect of F. nucleatum DnaK on the anti-cancer activity of cisplatin and 5FU. RESULTS: Our results show that both M. fermentans and F. nucleatum DnaKs reduce the effectiveness of cisplatin and 5FU. However, the use of ARV-1502 effectively restored the drugs' anti-cancer efficacy. CONCLUSIONS: Our findings offer a practical framework for designing and implementing novel personalized anti-cancer strategies by targeting specific bacterial DnaKs in patients with poor response to chemotherapy, underscoring the potential for microbiome-based personalized cancer therapies.

LncRNA FOXD1-AS1 regulates pancreatic cancer stem cell properties and 5-FU resistance by regulating the miR-570-3p/SPP1 axis as a ceRNA.

Cancer stem cells (CSCs) play a pivotal role in the pathogenesis of human cancers. Previous studies have highlighted the role of long non-coding RNA (lncRNA) in modulating the stemness of CSCs. In our investigation, we identified an upregulation of lncRNA FOXD1-AS1 in CSCs. The enforced expression of lncRNA FOXD1-AS1 promotes tumorigenesis and self-renewal in pancreatic cancer CSCs. Conversely, the knockdown of lncRNA FOXD1-AS1 inhibits tumorigenesis and self-renewal in pancreatic cancer CSCs. Furthermore, our findings reveal that lncRNA FOXD1-AS1 enhances self-renewal and tumorigenesis in pancreatic cancer CSCs by up-regulating osteopontin/secreted phosphoprotein 1(SPP1) and acting as a ceRNA to sponge miR-570-3p in pancreatic cancer (PC) CSCs. Additionally, lncRNA FOXD1-AS1 depleted pancreatic cancer cells exhibit heightened sensitivity to 5-FU-indued cell growth inhibition and apoptosis. Analysis of patient-derived xenografts (PDX) indicates that a low level of lncRNA FOXD1-AS1 may serve as a predictor of 5-FU benefits in PC patients. Moreover, the introduction of SPP1 can reverse the sensitivity of lncRNA FOXD1-AS1-knockdown PC cells to 5-FU-induced cell apoptosis. Importantly, molecular studies have indicated that the elevated levels of lncRNAFOXD1-AS1 in PC are facilitated through METTL3 and YTHDF1-dependent m6A methylation. In summary, our results underscore the critical functions of lncRNA FOXD1-AS1 in the self-renewal and tumorigenesis of pancreatic cancer CSCs, positioning lncRNA FOXD1-AS1 as a promising therapeutic target for PC.

The METTL3/TRAP1 axis as a key regulator of 5-fluorouracil chemosensitivity in colorectal cancer.

Colorectal cancer (CRC) remains a significant clinical challenge, with 5-Fluorouracil (5-FU) being the frontline chemotherapy. However, chemoresistance remains a major obstacle to effective treatment. METTL3, a key methyltransferase involved in RNA methylation processes, has been implicated in CRC carcinogenesis. However, its role in modulating CRC sensitivity to 5-FU remains elusive. In this study, we aimed to investigate the role and mechanisms of METTL3 in regulating 5-FU chemosensitivity in CRC cells. Initially, we observed that 5-FU treatment inhibited cell viability and induced apoptosis, accompanied by a reduction in METTL3 expression in HCT-116 and HCT-8 cells. Subsequent assays including drug sensitivity, EdU, colony formation, TUNEL staining, and flow cytometry revealed that METTL3 depletion enhanced 5-FU sensitivity and increased apoptosis induction both in vitro and in vivo. Conversely, METTL3 overexpression conferred resistance to 5-FU in both cell lines. Moreover, knockdown of METTL3 in 5-FU-resistant CRC cell lines HCT-116/FU and HCT-15/FU significantly decreased 5-FU tolerance and induced apoptosis upon 5-FU treatment. Mechanistically, we found that METTL3 regulated 5-FU sensitivity and apoptosis induction by modulating TRAP1 expression. Further investigations using m6A colorimetric ELISA, dot blot, MeRIP-qPCR and RNA stability assays demonstrated that METTL3 regulated TRAP1 mRNA stability in an m6A-dependent manner. Additionally, overexpression of TRAP1 mitigated the cytotoxic effects of 5-FU on CRC cells. In summary, our study uncovers the pivotal role of the METTL3/TRAP1 axis in modulating 5-FU chemosensitivity in CRC. These findings provide new insights into the mechanisms underlying CRC resistance to 5-FU and may offer potential targets for future therapeutic interventions.

Omission of 5-Fluorouracil Bolus From Multidrug Regimens for Advanced Gastrointestinal Cancers: A Multicenter Cohort Study.

BACKGROUND: 5-Fluorouracil (5-FU) is a major component of gastrointestinal cancer treatments. In multidrug regimens such as FOLFOX, FOLFIRI, and FOLFIRINOX, 5-FU is commonly administered as a bolus followed by an infusion. However, the pharmacologic rationale for incorporating the 5-FU bolus in these regimens is unclear, and there are other effective regimens for gastrointestinal cancers that do not include the bolus. The purpose of this study was to determine whether omission of the 5-FU bolus was associated with a difference in survival and toxicity. METHODS: A real-world database from Flatiron Health was queried for patients with advanced colorectal, gastroesophageal, and pancreatic cancers who received first-line FOLFOX, FOLFIRI, and FOLFIRINOX regimens. Cox proportional hazards and Kaplan-Meier analyses were performed to compare survival outcomes between patients who received the 5-FU bolus and those who did not. Inverse probability of treatment weighted (IPTW) analysis was performed to adjust for treatment selection bias. RESULTS: This study included 11,765 patients with advanced colorectal (n=8,670), gastroesophageal (n=1,481), and pancreatic (n=1,614) cancers. Among all first-line 5-FU multidrug regimens, 10,148 (86.3%) patients received a 5-FU bolus and 1,617 (13.7%) did not. After IPTW analysis, we found that omitting the bolus was not associated with a decrease in overall survival (hazard ratio, 0.99; 95% CI, 0.91-1.07; P=.74). However, omitting the bolus was associated with reductions in neutropenia (10.7% vs 22.7%; P<.01), thrombocytopenia (11.2% vs 16.1%; P<.01), and use of granulocyte colony-stimulating factors after treatment (19.6% vs 29.1%; P<.01). CONCLUSIONS: After adjusting for baseline clinical factors, we found that omission of the 5-FU bolus from FOLFOX, FOLFIRI, and FOLFIRINOX regimens was not associated with decreased survival, but resulted in decreased toxicity and possible health care savings.

Economic evaluation of personalized vs. standard dosing of 5-fluorouracil in first-line chemotherapy for metastatic colorectal cancer in Australia.

AIMS: Using pharmacokinetics (PK)-guided 5-fluorouracil (5-FU) for metastatic colorectal cancer (mCRC) improves overall survival (OS) and decreases toxicity, yet its value for money in the Australian setting is unknown. Our study assesses the cost-effectiveness of PK vs. body surface area (BSA) dosing of 5-FU for patients with mCRC. METHODS: We developed a semi-Markov model with four health states to compare PK-guided dosing within a FOLFOX regimen vs. BSA-guided dosing for mCRC patients from an Australian healthcare system perspective. Transition probabilities were derived from fitted survival models, with utility values obtained directly from published studies. We calculated direct healthcare costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs), and included both one-way and probabilistic sensitivity analyses. RESULTS: BSA-guided FOLFOX provided 1.291 QALYs at a cost of $36 379, compared with PK-guided FOLFOX which delivered 1.751 QALYs at a cost of $32 564. Therefore, PK-guided dosing emerges as the dominant strategy offering both better health outcomes and lower costs. The variables that had the greatest impact on the overall ICER were the adverse event rates in the BSA and PK groups, model time horizon, utility of progression-free survival and PREDICT assay cost. Our univariate and multivariate sensitivity analysis confirmed that the ICER for PK FOLFOX consistently remained below $50 000 per QALY across all tested variables. CONCLUSIONS: PK dose management of 5-FU-based chemotherapy in mCRC patients appears to be a cost-saving strategy in Australia. However, our model estimates are drawn from limited, low-quality evidence. Further evidence from randomized controlled trials (RCTs), directly comparing PK-based to BSA-based dosing across a variety of current regimens, is needed to address our model's uncertainties.

Ataxia telangiectasia and Rad3-related (ATR) inhibition by VE-822 potently reversed 5-flourouracil resistance in colorectal cancer cells through targeting DNA damage response.

BACKGROUND: VE-822 is a novel inhibitor of ATR, a key kinase involved in the DNA damage response pathway. The role of ATR inhibition in reversing drug resistance in various cancer types has been investigated. Therefore, this study investigated the effects of ATR inhibition by VE-822 on reversing 5-fluorouracil (5-FU) resistance in colorectal cancer cell line (Caco-2). METHODS: Caco-2 and 5-FU resistance Caco-2 (Caco-2/5-FU) cells were treated with 5-FU and VE-822, alone and in combination. Cell proliferation and viability were assessed by MTT assay and Trypan Blue staining. P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1) activities were measured by Rhodamine123 accumulation and uptake assay. The mRNA levels of P-gp, MRP-1, ataxia telangiectasia and Rad3-related (ATR) and checkpoint kinase 1 (CHK1) were measured by qRT-PCR. Western blot was used to measure the protein levels of P-gp, MRP-1, γ-H2AX, ATR and CHK1 in cells. 8-Oxo-2'-deoxyguanosine (8-oxo-dG) levels were determined via ELISA. Apoptosis was evaluated by ELISA death assay, DAPI staining and lactate dehydrogenase (LDH) assay. RESULTS: The Caco-2/5-FU cells showed lower levels of 5-FU mediated proliferation inhibition in comparison to Caco-2 cells. VE-822 decreased the IC50 value of 5-FU on resistant cells. In addition, the expression levels and activity of P-gp and MRP-1 were significantly decreased in resistant cells treated with VE-822 (P < 0.05). The combination of 5-FU and VE-822 increased apoptosis in Caco-2/5-FU cells by downregulating CHK1 and ATR and upregulating γ-H2AX and 8-oxo-dG. CONCLUSION: The simultaneous treatment of resistant colorectal cancer cells with 5-FU and ATR inhibitor, VE-822, was demonstrated to be effective in reversing drug resistance and potentiating 5-FU mediated anticancer effects via targeting DNA damage.

Stomatin-like protein 2 promotes cell proliferation and survival under 5-Fluorouracil stress in hepatocellular carcinoma.

BACKGROUND: The crucial role of STOML2 in tumor progression has been documented recently in various cancers. Previous studies have shown that STOML2 promoted cancer cell proliferation, but the underlying mechanism is not fully illustrated. METHODS AND RESULTS: The expression and clinical relevance of STOML2 in pan-cancer was analyzed by TIMER2 web platform in pan-cancer. The prognostic significance of STOML2 in HCC was evaluated utilizing KM curve and a nomogram model. Signaling pathways associated with STOML2 expression were discovered by GSEA. CCK-8 assay was performed to evaluate the proliferative capacity of HCC cells after manipulating STOML2 expression. Flow cytometry was utilized to analyze cell cycle progression. Results indicated that increased STOML2 expression in HCC linked to unfavorable clinical outcomes. Cell cycle and cell division related terms were enriched under conditions of elevated STOML2 expression via GSEA analysis. A notable decrease in cell proliferation was observed in MHCC97H with STOML2 knocked-down, accompanied by G1-phase arrest, up-regulation of p21, down-regulation of CyclinD1 and its regulatory factor MYC, while STOML2 overexpression in Huh7 showed the opposite results. These results indicated that STOML2 was responsible for HCC proliferation by regulating the expression level of MYC/cyclin D1 and p21. Furthermore, an inverse correlation was found between STOML2 expression and 5-FU sensitivity. CONCLUSIONS: STOML2 promotes cell cycle progression in HCC which is associated with activation of MYC/CyclinD1/p21 pathway, and modulates the response of HCC to 5-FU.

Intelligent nanovesicle for remodeling tumor microenvironment and circulating tumor chemoimmunotherapy amplification.

Imperceptible examination and unideal treatment effect are still intractable difficulties for the clinical treatment of pancreatic ductal adenocarcinoma (PDAC). At present, despite 5-fluorouracil (5-FU), as a clinical first-line FOLFIRINOX chemo-drug, has achieved significant therapeutic effects. Nevertheless, these unavoidable factors such as low solubility, lack of biological specificity and easy to induce immunosuppressive surroundings formation, severely limit their treatment in PDAC. As an important source of energy for many tumor cells, tryptophan (Trp), is easily degraded to kynurenine (Kyn) by indolamine 2,3- dioxygenase 1 (IDO1), which activates the axis of Kyn-AHR to form special suppressive immune microenvironment that promotes tumor growth and metastasis. However, our research findings that 5-FU can induce effectively immunogenic cell death (ICD) to further treat tumor by activating immune systems, while the secretion of interferon-γ (IFN-γ) re-induce the Kyn-AHR axis activation, leading to poor treatment efficiency. Therefore, a metal matrix protease-2 (MMP-2) and endogenous GSH dual-responsive liposomal-based nanovesicle, co-loading with 5-FU (anti-cancer drug) and NLG919 (IDO1 inhibitor), was constructed (named as ENP919@5-FU). The multifunctional ENP919@5-FU can effectively reshape the tumor immunosuppression microenvironment to enhance the effect of chemoimmunotherapy, thereby effectively inhibiting cancer growth. Mechanistically, PDAC with high expression of MMP-2 will propel the as-prepared nanovesicle to dwell in tumor region via shedding PEG on the nanovesicle surface, effectively enhancing tumor uptake. Subsequently, the S-S bond containing nanovesicle was cut via high endogenous GSH, leading to the continued release of 5-FU and NLG919, thereby enabling circulating chemoimmunotherapy to effectively cause tumor ablation. Moreover, the combination of ENP919@5-FU and PD-L1 antibody (αPD-L1) showed a synergistic anti-tumor effect on the PDAC model with abdominal cavity metastasis. Collectively, ENP919@5-FU nanovesicle, as a PDAC treatment strategy, showed excellent antitumor efficacy by remodeling tumor microenvironment to circulate tumor chemoimmunotherapy amplification, which has promising potential in a precision medicine approach.

Treatment of ocular surface squamous neoplasia in an Indian rural facility: a study of 38 eyes.

PURPOSE: To report the demographic profile, clinical presentation, and management outcomes of ocular surface squamous neoplasia (OSSN) treated with primary topical chemotherapy in a limited resource secondary eye care facility in rural parts of South India. METHODS: Retrospective interventional study of 38 eyes of 37 patients with OSSN treated with topical 1% 5-Fluorouracil (5FU), over a period of two years. RESULTS: The median age at presentation with OSSN was 44 years (mean, 46 years; range 13 to 74 years). Majority (76%) were males. The most common morphological variant was placoid OSSN (18, 47%). Limbus was the most common epicenter (31, 82%). Corneal OSSN was the most initially misdiagnosed variant (n = 3). Of the 38 eyes receiving one week on and 3-weeks off cycles of 5FU regimen, complete tumor resolution was achieved in 36 (95%) eyes. The median number of topical 5FU cycles for tumor resolution was 2 (mean, 2; range, 1 to 4). Over a median follow-up period of 5 months (mean, 6 months; range, 1 to 27 months), tumor recurrence was noted in 3 eyes (8%), of which one case had xeroderma pigmentosum with bilateral multifocal recurrence. Complication rate was 5% (n = 2), which included transient conjunctival hyperemia (n = 1), and bacterial keratitis (n = 1) which resolved with fortified antibiotics. CONCLUSION: Primary chemotherapy with topical 1% 5FU is a safe and effective management modality for OSSN at limited resource settings in rural India.

Semilicoisoflavone B induces oral cancer cell apoptosis by targeting claspin and ATR-Chk1 signaling pathways.

The prevalence of oral squamous cell carcinoma (OSCC) is increasing worldwide mainly due to poor oral hygiene and unrestricted lifestyle. Advanced-stage OSCC is associated with poor prognosis and a 5-year survival rate of only 30%-50%. The present study was designed to investigate the anticancer effect and mode of action of Glycyrrhiza-derived semilicoisoflavone B (SFB) in 5-fluorourasil (5FU)-resistant human OSCC cell lines. The study findings revealed that SFB significantly reduces OSCC cell viability and colony formation ability by arresting cell cycle at the G2/M and S phases and reducing the expressions of key cell cycle regulators including cyclin A, cyclin B, CDC2, and CDK2. The compound caused a significant induction in the percentage of nuclear condensation and apoptotic cells in OSCC. Regarding pro-apoptotic mode of action, SFB was found to increase Fas-associated death domain and death receptor 5 expressions and reduce decoy receptor 2 expression, indicating involvement of extrinsic pathway. Moreover, SFB was found to increase pro-apoptotic Bim expression and reduce anti-apoptotic Bcl-2 and Bcl-xL expressions, indicating involvement of intrinsic pathway. Moreover, SFB-mediated induction in cleaved caspases 3, 8, and 9 and cleaved poly(ADP-ribose) polymerase confirmed the induction of caspase-mediated apoptotic pathways. Regarding upstream signaling pathway, SFB was found to reduce extracellular signal regulated kinase 1/2 (ERK) phosphorylation to execute its pro-apoptotic activity. The Human Apoptotic Array findings revealed that SFB suppresses claspin expression, which in turn caused reduced phosphorylation of ATR, checkpoint kinase 1 (Chk1), Wee1, and CDC25C, indicating disruption of ATR-Chk1 signaling pathway by SFB. Taken together, these findings indicate that SFB acts as a potent anticancer compound against 5FU-resistant OSCC by modulating mitogen-activated protein kinase (MAPK) and ATR-Chk1 signaling pathways.

Schisandrin A can promote the anti-tumor effect of 5-Fu by reversing the immunosuppressive state of the body in rat.

In this study, based on Walker 256 in vitro experiments, CCK-8 assay, clone formation assay, wound healing assay, and flow cytometry were used to detect cell apoptosis and cell cycle. It was found that schisandrin may have significant anti-tumor effects in vitro by inhibiting TGF-ß/Smad signaling pathway. In addition, in vivo experiments, immunohistochemistry was used to observe the expression of HIF-1α, VEGF and VEGFR-2 in tumor tissues. It was found that schisandrin could significantly improve the immunosuppression induced by 5-Fu and enhance the antitumor effect of 5-Fu. The mechanism may be related to the inhibition of Wnt-1/ß-catenin signaling pathway.

Discovery of the Natural Bibenzyl Compound Erianin in Dendrobium Inhibiting the Growth and EMT of Gastric Cancer through Downregulating the LKB1-SIK2/3-PARD3 Pathway.

Erianin, a bibenzyl compound found in dendrobium extract, has demonstrated broad anticancer activity. However, its mechanism of action in gastric cancer (GC) remains poorly understood. LKB1 is a tumor-suppressor gene, and its mutation is an important driver of various cancers. Yet some studies have reported contradictory findings. In this study, we combined bioinformatics and in vitro and in vivo experiments to investigate the effect and potential mechanism of Erianin in the treatment of GC. The results show that LKB1 was highly expressed in patients' tumor tissues and GC cells, and it was associated with poor patient prognosis. Erianin could promote GC cell apoptosis and inhibit the scratch repair, migration, invasion, and epithelial-mesenchymal transition (EMT) characteristics. Erianin dose-dependently inhibited the expression of LKB1, SIK2, SIK3, and PARD3 but had no significant effect on SIK1. Erianin also inhibited tumor growth in CDX mice model. Unexpectedly, 5-FU also exhibited a certain inhibitory effect on LKB1. The combination of Erianin and 5-FU significantly improved the anti-tumor efficacy of 5-FU in the growth of GC cells and xenograft mouse models. In summary, Erianin is a potential anti-GC compound that can inhibit GC growth and EMT properties by targeting the LKB1-SIK2/3-PARD3-signaling axis. The synergistic effect of Erianin and 5-FU suggests a promising therapeutic strategy for GC treatment.

HPMC-Zein Film-forming Gel Loaded with 5-Fluorouracil Coupled with CO2 Laser Dermabrasion for Managing Stable Vitiligo.

Vitiligo is a significant dermatological challenge affecting 0.5 to 2% of the global population. Despite the various existing medical approaches, current vitiligo treatments are far from ideal. The present study aimed to prepare and evaluate a film-forming gel of 5 fluorouracil (5FU) using different ratios of hydroxypropyl methylcellulose (HPMC) and Zein for treating vitiligo. The prepared film-forming gels were fully characterized in terms of morphology, Fourier-transform infrared spectroscopy, drug content, pH, drying time, in-vitro drug release, and clinical investigation. A 32-full factorial design was used to study the impact of varying concentrations of HPMC (X1) and Zein (X2) on the percentage of 5FU released (Y1) from the prepared film-forming gels. Scanning electron microscopy (SEM) revealed a cross-linked network structure between polymers. An increase in HPMC concentration (2-4%) correlated with higher 5FU release, whereas increased Zein concentration (1-2%) resulted in reduced 5FU release. Furthermore, patients treated with 5FU film-forming gel after dermabrasion with fractional CO2 (FCO2) laser exhibited a significant decrease in JAK3 gene expression and higher effectiveness than those treated with FCO2 laser alone. Our results suggest that the film-forming gel of 5FU is promising as an effective formulation for treating vitiligo.

Development of nanoemulgel of 5-Fluorouracil for skin melanoma using glycyrrhizin as a penetration enhancer.

The purpose of this study was to enhance the topical delivery of 5-Fluorouracil (5-FU), a cancer treatment, by developing a nanoemulgel formulation. Glycyrrhizin (GLY), a natural penetration enhancer has been investigated to exhibit synergistic effects with 5-FU in inhibiting melanoma cell proliferation and inducing apoptosis, Hence, GLY, along with suitable lipids was utilized to create an optimized nanoemulsion (NE) based gel. Solubility studies and ternary phase diagram revealed isopropyl myristate (IPM), Span 80, Tween 80 as Smix and Transcutol P as co-surfactant. IPM demonstrates excellent solubilizing properties facilitates higher drug loading, ensuring efficient delivery to the target site.,The optimized formulation consisting of 40 % IPM, 30 % of mixture of Tween80: Span80 (Smix) and 15 % Transcutol P provides with a nanometric size of 64.1 ± 5.13 nm and drug loading of 97.3 ± 5.83 %. The optimized formulation observed with no creaming and breakeing of NE and found thermodynamically stable during different stress conditions (temperatures of 4.0 °C and 45.0 °C) and physical thawing (-21.0 ± 0.50 °C to 20.0 ± 0.50 °C). The NE was then transformed into a nanoemulgel (NEG) using 1.5 % w/w Carbopol base and 0.1 % w/w glycyrrhizin. The ex vivo permeability studies showed significant enhancements in drug permeability with the GLY-based 5-FU-NEG formulation compared to pure 5-FU gel in excised pig skin upto1440 min in PBS 7.4 as receptor media. The IC50 values for Plain 5-FU gel, 5-FU-NEG, and GLY-based 5-FU-NEG were found to be 20 µg/mL, 1.1 µg/mL, and 0.1 µg/mL, respectively in B16F10 cell lines. The percentage intracellular uptake of GLY-5-FU-NEG and 5-FU-NEG was found to be 44.3 % and 53.6 %, respectively. GLY-based 5-FU-NEG formulation showed alterations in cell cycle distribution, in compared to 5-FU-NE gel. The overall findings suggest that the GLY-based 5-FU-NEG holds promise for improving anti-melanoma activity.