Study on the difference and regularity of tongue images in 309 patients with different pathological stages of non-small cell lung cancer.

BACKGROUND: Tongue diagnosis is a crucial traditional Chinese medicine (TCM) inspection method for TCM syndrome differentiation and treatment. OBJECTIVE: The primary research focus was on tongue image characteristic parameters of patients with non-small cell lung cancer (NSCLC). Analysis of the tongue image parameters of various pathological stages of NSCLC provides technical support for establishing an integrated Chinese and Western auxiliary diagnosis and efficacy evaluation medicine system for lung cancer that integrates tongue image features. METHODS: Tongue image characteristics of 309 patients with NSCLC and 206 controls were collected and analyzed clinically. The T-test or rank sum test and logistic regression analysis were applied to analyze the characteristics of tongue image indicators of different pathological stages of NSCLC. RESULTS: There were differences in tongue image characteristics in the NSCLC group compared to the control group. The tongue quality and brightness of the tongue coating in the NSCLC group increased, the red component was reduced, the tongue coating thickened, and the yellow component increased compared to the healthy control group. A comparison of tongue image indexes of NSCLC in different pathological stages showed that stage IV had lower TB-b and higher TB-a than stage I. In addition, stage IV had lower TB-b than stage II + III, showing an increase in the blue and red components of the tongue in stage IV and the appearance of cyanotic tongue features. CONCLUSION: The tongue image characteristics of NSCLC patients differed from those of the control group. Tongue imaging indicators can reflect the characteristics of tongue images of patients with NSCLC. The tongue image characteristics of patients with stage IV lung cancer are bluish and purple compared with those with stage I, II, and III. It is suggested that the tongue's image characteristics can be used as a reference for the pathological classification of NSCLC and judgment of the disease process.

RNA modification in cardiovascular disease: implications for therapeutic interventions.

Cardiovascular disease (CVD) is the leading cause of death in the world, with a high incidence and a youth-oriented tendency. RNA modification is ubiquitous and indispensable in cell, maintaining cell homeostasis and function by dynamically regulating gene expression. Accumulating evidence has revealed the role of aberrant gene expression in CVD caused by dysregulated RNA modification. In this review, we focus on nine common RNA modifications: N6-methyladenosine (m6A), N1-methyladenosine (m1A), 5-methylcytosine (m5C), N7-methylguanosine (m7G), N4-acetylcytosine (ac4C), pseudouridine (Ψ), uridylation, adenosine-to-inosine (A-to-I) RNA editing, and modifications of U34 on tRNA wobble. We summarize the key regulators of RNA modification and their effects on gene expression, such as RNA splicing, maturation, transport, stability, and translation. Then, based on the classification of CVD, the mechanisms by which the disease occurs and progresses through RNA modifications are discussed. Potential therapeutic strategies, such as gene therapy, are reviewed based on these mechanisms. Herein, some of the CVD (such as stroke and peripheral vascular disease) are not included due to the limited availability of literature. Finally, the prospective applications and challenges of RNA modification in CVD are discussed for the purpose of facilitating clinical translation. Moreover, we look forward to more studies exploring the mechanisms and roles of RNA modification in CVD in the future, as there are substantial uncultivated areas to be explored.

Skp2-mediated MLKL degradation confers cisplatin-resistant in non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) is the most prevalent type of cancer and the leading cause of cancer-related death. Chemotherapeutic resistance is a major obstacle in treating NSCLC patients. Here, we discovered that the E3 ligase Skp2 is overexpressed, accompanied by the downregulation of necroptosis-related regulator MLKL in human NSCLC tissues and cell lines. Knockdown of Skp2 inhibited viability, anchorage-independent growth, and in vivo tumor development of NSCLC cells. We also found that the Skp2 protein is negatively correlated with MLKL in NSCLC tissues. Moreover, Skp2 is increased and accompanied by an upregulation of MLKL ubiquitination and degradation in cisplatin-resistant NSCLC cells. Accordingly, inhibition of Skp2 partially restores MLKL and sensitizes NSCLC cells to cisplatin in vitro and in vivo. Mechanistically, Skp2 interacts and promotes ubiquitination-mediated degradation of MLKL in cisplatin-resistant NSCLC cells. Our results provide evidence of an Skp2-dependent mechanism regulating MLKL degradation and cisplatin resistance, suggesting that targeting Skp2-ubiquitinated MLKL degradation may overcome NSCLC chemoresistance.

Dioscin inhibiting EGFR-mediated Survivin expression promotes apoptosis in oral squamous cell carcinoma cells.

Overexpression of survivin plays a crucial role in tumorigenesis and correlates with poor prognosis in human malignancies, including oral squamous cell carcinoma (OSCC). Thus, survivin has been proposed as an attractive target for new antitumor interventions. In the present study, we found that a natural compound, Dioscin, inhibited OSCC cells by reducing the survivin protein level and activating apoptotic signaling. Dioscin inhibits survivin expression by interrupting EGFR binding to the AT-rich sequences (ATRSs) at the survivin promoter, eventually promoting survivin-mediated cell apoptosis. The in vivo study showed that Dioscin suppressed the tumor development of SCC25 cells. Furthermore, the immunohistochemistry (IHC) results revealed that treated with Dioscin reduced the protein levels of EGFR and survivin in SCC25 xenograft tumors. Overall, our findings indicate that targeting the EGFR-survivin axis might be a promising OSCC treatment strategy.

Neoadjuvant therapy with anlotinib in a locally advanced and pulmonary metastasis PTC patient harboring TERT promoter and BRAFV600E mutations: a case report.

A 71-year-old woman with recurrent papillary thyroid carcinoma (PTC) was referred to our hospital. A computed tomography scan revealed extensive recurrence in the neck, invading sternocleidomastoid muscle, internal jugular vein, sternal end of the clavicle, strap muscle and skin; and lateral compartment and subclavian lymph nodes were also involved. Multiple pulmonary micrometastases also noticed. The tumor was considered unresectable; however, the patient was unwilling to accept highly invasive surgery. Therefore, we initiated neoadjuvant therapy with anlotinib, 12mg p.o. daily with a 2-week on/1-week off regimen. The tumor shrunk to resectable state after 4 cycles of treatment, and after 3 weeks of withdrawal, successful surgical resection without gross tumor residual was performed. Pathology confirmed as classic PTC harboring coexistent TERT promoter and BRAFV600E mutations by NGS. After anlotinib therapy, apoptosis induction was observed, and proliferation increased, which was due to three weeks of anlotinib withdraw. Structual recurrence was recorded at 6 months after operation due to no further treatment was taken. Our finding suggests that anlotinib could represent as a good treatment option for patients with locally advanced (with or without distant metastasis) PTC; Anlotinib treatment resulted in sufficient reduction of the tumor mass to enable total thyroidectomy and radioactive iodine treatment, providing long-term control of the disease.

PD-L1 translocation to the plasma membrane enables tumor immune evasion through MIB2 ubiquitination.

Programmed death-ligand 1 (PD-L1), a critical immune checkpoint ligand, is a transmembrane protein synthesized in the endoplasmic reticulum of tumor cells and transported to the plasma membrane to interact with programmed death 1 (PD-1) expressed on T cell surface. This interaction delivers coinhibitory signals to T cells, thereby suppressing their function and allowing evasion of antitumor immunity. Most companion or complementary diagnostic devices for assessing PD-L1 expression levels in tumor cells used in the clinic or in clinical trials require membranous staining. However, the mechanism driving PD-L1 translocation to the plasma membrane after de novo synthesis is poorly understood. Herein, we showed that mind bomb homolog 2 (MIB2) is required for PD-L1 transportation from the trans-Golgi network (TGN) to the plasma membrane of cancer cells. MIB2 deficiency led to fewer PD-L1 proteins on the tumor cell surface and promoted antitumor immunity in mice. Mechanistically, MIB2 catalyzed nonproteolytic K63-linked ubiquitination of PD-L1, facilitating PD-L1 trafficking through Ras-associated binding 8-mediated (RAB8-mediated) exocytosis from the TGN to the plasma membrane, where it bound PD-1 extrinsically to prevent tumor cell killing by T cells. Our findings demonstrate that nonproteolytic ubiquitination of PD-L1 by MIB2 is required for its transportation to the plasma membrane and tumor cell immune evasion.

Neoadjuvant therapy with anlotinib in a locally advanced and pulmonary metastasis PTC patient harboring TERT promoter and BRAFV600E mutations: a case report

SUMMARY A 71-year-old woman with recurrent papillary thyroid carcinoma (PTC) was referred to our hospital. A computed tomography scan revealed extensive recurrence in the neck, invading sternocleidomastoid muscle, internal jugular vein, sternal end of the clavicle, strap muscle and skin; and lateral compartment and subclavian lymph nodes were also involved. Multiple pulmonary micrometastases also noticed. The tumor was considered unresectable; however, the patient was unwilling to accept highly invasive surgery. Therefore, we initiated neoadjuvant therapy with anlotinib, 12mg p.o. daily with a 2-week on/1-week off regimen. The tumor shrunk to resectable state after 4 cycles of treatment, and after 3 weeks of withdrawal, successful surgical resection without gross tumor residual was performed. Pathology confirmed as classic PTC harboring coexistent TERT promoter and BRAFV600E mutations by NGS. After anlotinib therapy, apoptosis induction was observed, and proliferation increased, which was due to three weeks of anlotinib withdraw. Structual recurrence was recorded at 6 months after operation due to no further treatment was taken. Our finding suggests that anlotinib could represent as a good treatment option for patients with locally advanced (with or without distant metastasis) PTC; Anlotinib treatment resulted in sufficient reduction of the tumor mass to enable total thyroidectomy and radioactive iodine treatment, providing long-term control of the disease.

Stabilization of MCL-1 by E3 ligase TRAF4 confers radioresistance.

The E3 ligase TNF receptor-associated factor 4 (TRAF4) is frequently overexpressed and closely related to poor prognosis in human malignancies. However, its effect on carcinogenesis and radiosensitivity in oral squamous cell carcinoma (OSCC) remains unclear. The present study found that TRAF4 was significantly upregulated in primary and relapsed OSCC tumor tissues. Depletion of TRAF4 markedly improved the sensitivity of OSCC cells to irradiation (IR) treatment, showing that tumor cell proliferation, colony formation and xenograft tumor growth were reduced. Mechanistically, IR promoted the interaction between TRAF4 and Akt to induce Akt K63-mediated ubiquitination and activation. TRAF4 knockout inhibited the phosphorylation of Akt and upregulated GSK3ß activity, resulting in increased myeloid cell leukemia-1 (MCL-1) S159 phosphorylation, which disrupted the interaction of MCL-1 with Josephin domain containing 1 (JOSD1), and ultimately induced MCL-1 ubiquitination and degradation. Moreover, TRAF4 was positively correlated with MCL-1 in primary and in radiotherapy-treated, relapsed tumor tissues. An MCL-1 inhibitor overcame radioresistance in vitro and in vivo. Altogether, the present findings suggest that TRAF4 confers radioresistance in OSCC by stabilizing MCL-1 through Akt signaling, and that targeting TRAF4 may be a promising therapeutic strategy to overcome radioresistance in OSCC.

Epithelial-mesenchymal reprogramming by KLF4-regulated Rictor expression contributes to metastasis of non-small cell lung cancer cells.

Non-small cell lung cancer (NSCLC) is one of the deadliest cancers in the world. Metastasis is considered one of the leading causes of treatment failure and death in NSCLC patients. A crucial factor of promoting metastasis in epithelium-derived carcinoma has been considered as epithelial-mesenchymal transition (EMT). Rictor, one of the components of mTORC2, has been reportedly involved in EMT and metastasis of human malignancies. However, the regulatory mechanisms of Rictor, Rictor-mediated EMT and metastasis in cancers remain unknown. Our present study indicates that Rictor is highly expressed in human NSCLC cell lines and tissues and is regulated, at least partially, at the transcriptional level. Knockdown of Rictor expression causes phenotype alterations through EMT, which is accompanied by the impairment of migration and invasion ability in NSCLC cells. Additionally, we have cloned and identified the human Rictor core promoter for the first time and confirmed that transcription factor KLF4 directly binds to the Rictor promoter and transcriptionally upregulated Rictor expression. Knockdown of KLF4 results in Rictor's downregulation accompanied by a series of characteristic changes of mesenchymal-epithelial transition (MET) and significantly decreases migration, invasion as well as metastasis of NSCLC cells. Re-introducing Rictor in KLF4-knockdown NSCLC cells partially reverses the epithelial phenotype to the mesenchymal phenotype and attenuates the inhibition of cell migration and invasion caused by KLF4 knocking down. Knockdown of KLF4 prevents mTOR/Rictor interaction and metastasis of NSCLC in vivo. The understanding of the regulator upstream of Rictor may provide an opportunity for the development of new inhibitors and the rational design of combination regimens based on different metastasis-related molecular targets and finally prevents cancer metastasis.

Skp2 stabilizes Mcl-1 and confers radioresistance in colorectal cancer.

Overexpression of Skp2 plays a critical role in tumorigenesis and correlates with poor prognosis in human malignancies. Thus, Skp2 has been proposed as an attractive target for anti-tumor interventions. The expression of Skp2 in human colorectal cancer (CRC) and the role of Skp2 in tumorigenic properties and irradiation sensitivities of CRC cells were examined by anchorage-dependent and -independent growth assays, immunoblot, flow cytometry, immunohistochemical staining, ubiquitination analysis, co-immunoprecipitation assay, CRISPR-Cas9-based gene knockout, and xenograft experiments. Skp2 is highly expressed in CRC patient tissues. Blocking Skp2 expression reduces the tumorigenic properties of CRC cells in vitro and in vivo. Depletion of Skp2 confers sensitivity to irradiation of CRC cells. Skp2 deficiency enhances irradiation-induced intrinsic apoptosis by facilitating E3 ligase FBW7-mediated Mcl-1 ubiquitination and degradation. Knockout of Skp2 sensitizes CRC cells to irradiation treatments in vivo. Our findings indicate that Skp2 stabilizes Mcl-1, and targeting Skp2 in combination with traditional radiotherapy might be efficacious in treating CRC.

Successful management of a rare case of juvenile giant right ventricular myxoma.

Primary cardiac tumors are extremely uncommon in young children and infants. Cardiac myxoma are typically found in the atria, predominately in the left atrium, with relatively few found on the right side, such as in the right ventricle or pulmonary artery. Numerous significant complications, including sudden death, can result from obstruction of the main pulmonary artery trunk and right ventricular outflow tract. Here, we describe the case of a 14-year-old Chinese girl diagnosed with a right ventricular myxoma located in the right ventricle and extended into the main pulmonary trunk. Complete resection of the myxoma and histological confirmation were performed.

Identification and Integrate Analysis of Key Biomarkers for Diagnosis and Prognosis of Non-Small Cell Lung Cancer Based on Bioinformatics Analysis.

Background: Non-small cell lung cancer (NSCLC) is the most common type of lung cancer affecting humans. However, appropriate biomarkers for diagnosis and prognosis have not yet been established. Here, we evaluated the gene expression profiles of patients with NSCLC to identify novel biomarkers. Methods: Three datasets were downloaded from the Gene Expression Omnibus (GEO) database, and differentially expressed genes were analyzed. Venn diagram software was applied to screen differentially expressed genes, and gene ontology functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed. Cytoscape was used to analyze protein-protein interactions (PPI) and Kaplan-Meier Plotter was used to evaluate the survival rates. Oncomine database, Gene Expression Profiling Interactive Analysis (GEPIA), and The Human Protein Atlas (THPA) were used to analyze protein expression. Quantitative real-time polymerase (qPCR) chain reaction was used to verify gene expression. Results: We identified 595 differentially expressed genes shared by the three datasets. The PPI network of these differentially expressed genes had 202 nodes and 743 edges. Survival analysis identified 10 hub genes with the highest connectivity, 9 of which (CDC20, CCNB2, BUB1, CCNB1, CCNA2, KIF11, TOP2A, NDC80, and ASPM) were related to poor overall survival in patients with NSCLC. In cell experiments, CCNB1, CCNB2, CCNA2, and TOP2A expression levels were upregulated, and among different types of NSCLC, these four genes showed highest expression in large cell lung cancer. The highest prognostic value was detected for patients who had successfully undergone surgery and for those who had not received chemotherapy. Notably, CCNB1 and CCNA2 showed good prognostic value for patients who had not received radiotherapy. Conclusion: CCNB1, CCNB2, CCNA2, and TOP2A expression levels were upregulated in patients with NSCLC. These genes may be meaningful diagnostic biomarkers and could facilitate the development of targeted therapies.

Targeting Aurora B kinase with Tanshinone IIA suppresses tumor growth and overcomes radioresistance.

Aurora B kinase is aberrantly overexpressed in various tumors and shown to be a promising target for anti-cancer therapy. In human oral squamous cell carcinoma (OSCC), the high protein level of Aurora B is required for maintaining of malignant phenotypes, including in vitro cell growth, colony formation, and in vivo tumor development. By molecular modeling screening of 74 commercially available natural products, we identified that Tanshinone IIA (Tan IIA), as a potential Aurora B kinase inhibitor. The in silico docking study indicates that Tan IIA docks into the ATP-binding pocket of Aurora B, which is further confirmed by in vitro kinase assay, ex vivo pull-down, and ATP competitive binding assay. Tan IIA exhibited a significant anti-tumor effect on OSCC cells both in vitro and in vivo, including reduction of Aurora B and histone H3 phosphorylation, induction of G2/M cell cycle arrest, increase the population of polyploid cells, and promotion of apoptosis. The in vivo mouse model revealed that Tan IIA delayed tumor growth of OSCC cells. Tan IIA alone or in combination with radiation overcame radioresistance in OSCC xenograft tumors. Taken together, our data indicate that Tan IIA is an Aurora B kinase inhibitor with therapeutic potentials for cancer treatment.

MYD88 L265P elicits mutation-specific ubiquitination to drive NF-κB activation and lymphomagenesis.

Myeloid differentiation primary response protein 88 (MYD88) is a critical universal adapter that transduces signaling from Toll-like and interleukin receptors to downstream nuclear factor-κB (NF-κB). MYD88L265P (leucine changed to proline at position 265) is a gain-of-function mutation that occurs frequently in B-cell malignancies such as Waldenstrom macroglobulinemia. In this study, E3 ligase RING finger protein family 138 (RNF138) catalyzed K63-linked nonproteolytic polyubiquitination of MYD88L265P, resulting in enhanced recruitment of interleukin-1 receptor-associated kinases and elevated NF-κB activation. However, RNF138 had little effect on wild-type MYD88 (MYD88WT). With either RNF138 knockdown or mutation on MYD88 ubiquitination sites, MYD88L265P did not constitutively activate NF-κB. A20, a negative regulator of NF-κB signaling, mediated K48-linked polyubiquitination of RNF138 for proteasomal degradation. Depletion of A20 further augmented MYD88L265P-mediated NF-κB activation and lymphoma growth. Furthermore, A20 expression correlated negatively with RNF138 expression and NF-κB activation in lymphomas with MYD88L265P and in those without. Strikingly, RNF138 expression correlated positively with NF-κB activation in lymphomas with MYD88L265P, but not in those without it. Our study revealed a novel mutation-specific biochemical reaction that drives B-cell oncogenesis, providing a therapeutic opportunity for targeting oncogenic MYD88L265P, while sparing MYD88WT, which is critical to innate immunity.

RIP1/RIP3/MLKL-mediated necroptosis contributes to vinblastine-induced myocardial damage.

Vinblastine (VBL) has been considered as a first-line anti-tumor drug for many years. However, vinblastine-caused myocardial damage has been continually reported. The underlying molecular mechanism of the myocardial damage remains unknown. Here, we show that vinblastine induces myocardial damage and necroptosis is involved in the vinblastine-induced myocardial damage both in vitro and in vivo. The results of WST-8 and flow cytometry analysis show that vinblastine causes damage to H9c2 cells, and the results of animal experiments show that vinblastine causes myocardial cell damage. The necrosome components, receptor-interacting protein 1 (RIP1) receptor-interacting protein 3 (RIP3), are significantly increased in vinblastine-treated H9c2 cells, primary neonatal rat ventricular myocytes and rat heart tissues. And the downstream substrate of RIP3, mixed lineage kinase domain like protein (MLKL) was also increased. Pre-treatment with necroptosis inhibitors partially inhibits the necrosome components and MLKL levels and alleviates vinblastine-induced myocardial injury both in vitro and in vivo. This study indicates that necroptosis participated in vinblastine-evoked myocardial cell death partially, which would be a potential target for relieving the chemotherapy-related myocardial damage.

Ubiquitination of the DNA-damage checkpoint kinase CHK1 by TRAF4 is required for CHK1 activation.

BACKGROUND: Aberrant activation of DNA damage response (DDR) is a major cause of chemoresistance in colorectal cancer (CRC). CHK1 is upregulated in CRC and contributes to therapeutic resistance. We investigated the upstream signaling pathways governing CHK1 activation in CRC. METHODS: We identified CHK1-binding proteins by mass spectrometry analysis. We analyzed the biologic consequences of knockout or overexpression of TRAF4 using immunoblotting, immunoprecipitation, and immunofluorescence. CHK1 and TRAF4 ubiquitination was studied in vitro and in vivo. We tested the functions of TRAF4 in CHK1 phosphorylation and CRC chemoresistance by measuring cell viability and proliferation, anchorage-dependent and -independent cell growth, and mouse xenograft tumorigenesis. We analyzed human CRC specimens by immunohistochemistry. RESULTS: TRAF4 catalyzed the ubiquitination of CHK1 in multiple CRC cell lines. Following DNA damage, ubiquitination of CHK1 at K132 by TRAF4 is required for CHK1 phosphorylation and activation mediated by ATR. Notably, TRAF4 was highly expressed in chemotherapy-resistant CRC specimens and positively correlated with phosphorylated CHK1. Furthermore, depletion of TRAF4 impaired CHK1 activity and sensitized CRC cells to fluorouracil and other chemotherapeutic agents in vitro and in vivo. CONCLUSIONS: These data reveal two novel steps required for CHK1 activation in which TRAF4 serves as a critical intermediary and suggest that inhibition of the ATR-TRAF4-CHK1 signaling may overcome CRC chemoresistance.

Deguelin suppresses non-small cell lung cancer by inhibiting EGFR signaling and promoting GSK3ß/FBW7-mediated Mcl-1 destabilization.

Activating mutations of epidermal growth factor receptor (EGFR) play crucial roles in the oncogenesis of human non-small cell lung cancer (NSCLC). By screening 79 commercially available natural products, we found that the natural compound deguelin exhibited a profound anti-tumor effect on NSCLC via directly down-regulating of EGFR-signaling pathway. Deguelin potently inhibited in vitro EGFR kinase activity of wild type (WT), exon 19 deletion, and L858R/T790M-mutated EGFR. The in silico docking study indicated that deguelin was docked into the ATP-binding pocket of EGFRs. By suppression of EGFR signaling, deguelin inhibited anchorage-dependent, and independent growth of NSCLC cell lines, and significantly delayed tumorigenesis in vivo. Further study showed that deguelin inhibited EGFR and downstream kinase Akt, which resulted in the activation of GSK3ß and eventually enhanced Mcl-1 phosphorylation at S159. Moreover, deguelin promoted the interaction between Mcl-1 and E3 ligase SCFFBW7, which enhanced FBW7-mediated Mcl-1 ubiquitination and degradation. Additionally, phosphorylation of Mcl-1 by GSK3ß is a prerequisite for FBW7-mediated Mcl-1 destruction. Depletion or pharmacological inactivation of GSK3ß compromised deguelin-induced Mcl-1 ubiquitination and reduction. Taken together, our data indicate that enhancement of ubiquitination-dependent Mcl-1 turnover might be a promising approach for cancer treatment.

Cdh1-mediated Skp2 degradation by dioscin reprogrammes aerobic glycolysis and inhibits colorectal cancer cells growth.

BACKGROUND: The F-box protein S-phase kinase-associated protein 2 (Skp2) is overexpressed and correlated with poor prognosis in human malignancies, including colorectal cancer (CRC). METHODS: A natural product library was used for natural compound screening through glycolysis analysis. The expression of Skp2 in CRCs and the inhibitory effect of dioscin on glycolysis were examined through methods of immunoblot, immunofluorescence, immunohistochemical staining, anchorage-dependent and -independent growth assays, EdU incorporation assay, ubiquitination analysis, co-immunoprecipitation assay, CRISPR-Cas9-based gene knockout, and xenograft experiment. FINDINGS: We demonstrated that Skp2 was highly expressed in CRC tissues and cell lines. Knockout of Skp2 inhibited HK2 and glycolysis and decreased CRC cell growth in vitro and in vivo. We screened 88 commercially available natural products and found that dioscin, a natural steroid saponin derived from several plants, significantly inhibited glycolysis in CRC cells. Dioscin decreased the protein level of Skp2 by shortening the half-life of Skp2. Further study showed that dioscin attenuated Skp2 phosphorylation on S72 and promoted the interaction between Skp2 and Cdh1, which eventually enhanced Skp2 lysine 48 (K48)-linked polyubiquitination and degradation. Depletion of Cdh1 impaired dioscin-induced Skp2 reduction, rescued HK2 expression, and glycolysis in CRC cells. Finally, dioscin delayed the in vivo tumor growth, promoted Skp2 ubiquitination, and inhibited Skp2 expression in a mouse xenograft model. INTERPRETATION: This study suggests that in addition to pharmacological inactivation of Skp2, enhancement of ubiquitination-dependent Skp2 turnover is a promising approach for cancer treatment.

Xanthohumol inhibits colorectal cancer cells via downregulation of Hexokinases II-mediated glycolysis.

Deregulation of glycolysis is a common phenomenon in human colorectal cancer (CRC). In the present study, we reported that Hexokinase 2 (HK2) is overexpressed in human CRC tissues and cell lines, knockout of HK2 inhibited cell proliferation, colony formation, and xenograft tumor growth. We demonstrated that the natural compound, xanthohumol, has a profound anti-tumor effect on CRC via down-regulation of HK2 and glycolysis. Xanthohumol suppressed CRC cell growth both in vitro and in vivo. Treatment with xanthohumol promoted the release of cytochrome C and activated the intrinsic apoptosis pathway. Moreover, our results revealed that xanthohumol down-regulated the EGFR-Akt signaling, exogenous overexpression of constitutively activated Akt1 significantly impaired xanthohumol-induced glycolysis suppression and apoptosis induction. Our results suggest that targeting HK2 appears to be a new approach for clinical CRC prevention or treatment.

Skp2-mediated ubiquitination and mitochondrial localization of Akt drive tumor growth and chemoresistance to cisplatin.

The E3 ligase S-phase kinase-associated protein 2(Skp2) is overexpressed in human cancers and correlated with poor prognosis, but its contributions to tumorigenesis and chemoresistance in nasopharyngeal carcinoma (NPC) are not evident. Herein we show that Skp2 is highly expressed in NPC tumor tissues and cell lines. Knockdown of Skp2 suppresses tumor cell growth, colony formation, glycolysis, and in vivo tumor growth. Skp2 promotes Akt K63-mediated ubiquitination and activation, which is required for EGF-induced Akt mitochondrial localization. Importantly, K63-linked ubiquitination enhances the interaction between Akt and HK2 and eventually increases HK2 phosphorylation on Thr473 and mitochondrial localization. Overexpression of Skp2 impaired the intrinsic apoptotic pathway and confers cisplatin resistance. Moreover, ectopic expression of Myr-Akt1 or phosphomimetic HK2-T473D rescued cisplatin-induced tumor suppression in Skp2 knockdown stable cells. Also, depletion of Akt ubiquitination enhances the antitumor efficacy of cisplatin in vitro and in vivo. Finally, we demonstrated that Skp2 is positively correlated with p-Akt and HK2 in NPC tumor tissues. This study highlights the clinical value of Skp2 targeting in NPC treatment.