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The reprogramming of lipid metabolism and its association with oncogenic signaling pathways within the tumor microenvironment (TME) have emerged as significant hallmarks of cancer. Lipid metabolism is defined as a complex set of molecular processes including lipid uptake, synthesis, transport, and degradation. The dysregulation of lipid metabolism is affected by enzymes and signaling molecules directly or indirectly involved in the lipid metabolic process. Regulation of lipid metabolizing enzymes has been shown to modulate cancer development and to avoid resistance to anticancer drugs in tumors and the TME. Because of this, understanding the metabolic reprogramming associated with oncogenic progression is important to develop strategies for cancer treatment. Recent advances provide insight into fundamental mechanisms and the connections between altered lipid metabolism and tumorigenesis. In this review, we explore alterations to lipid metabolism and the pivotal factors driving lipid metabolic reprogramming, which exacerbate cancer progression. We also shed light on the latest insights and current therapeutic approaches based on small molecular inhibitors and phytochemicals targeting lipid metabolism for cancer treatment. Further investigations are worthwhile to fully understand the underlying mechanisms and the correlation between altered lipid metabolism and carcinogenesis. [ABSTRACT FROM AUTHOR]

Cancer tissues are not just simple masses of malignant cells, but rather complex and heterogeneous collections of cellular and even non-cellular components, such as endothelial cells, stromal cells, immune cells, and collagens, referred to as tumor microenvironment (TME). These multiple players in the TME develop dynamic interactions with each other, which determines the characteristics of the tumor. Platelets are the smallest cells in the bloodstream and primarily regulate blood coagulation and hemostasis. Notably, cancer patients often show thrombocytosis, a status of an increased platelet number in the bloodstream, as well as the platelet infiltration into the tumor stroma, which contributes to cancer promotion and progression. Thus, platelets function as one of the important stromal components in the TME, emerging as a promising chemotherapeutic target. However, the use of traditional antiplatelet agents, such as aspirin, has limitations mainly due to increased bleeding complications. This requires to implement new strategies to target platelets for anti-cancer effects. In oral squamous cell carcinoma (OSCC) patients, both high platelet counts and low tumor-stromal ratio (high stroma) are strongly correlated with increased metastasis and poor prognosis. OSCC tends to invade adjacent tissues and bones and spread to the lymph nodes for distant metastasis, which is a huge hurdle for OSCC treatment in spite of relatively easy access for visual examination of precancerous lesions in the oral cavity. Therefore, locoregional control of the primary tumor is crucial for OSCC treatment. Similar to thrombocytosis, higher expression of podoplanin (PDPN) has been suggested as a predictive marker for higher frequency of lymph node metastasis of OSCC. Cumulative evidence supports that platelets can directly interact with PDPN-expressing cancer cells via C-type lectin-like receptor 2 (CLEC2), contributing to cancer cell invasion and metastasis. Thus, the platelet CLEC2-PDPN axis could be a pinpoint target to inhibit interaction between platelets and OSCC, avoiding undesirable side effects. Here, we will review the role of platelets in cancer, particularly focusing on CLEC2-PDPN interaction, and will assess their potentials as therapeutic targets for OSCC treatment. [ABSTRACT FROM AUTHOR]

A new iridoid ( 1) was isolated from the stems of Viburnum erosum along with two known iridoids, 7-O-tigloylsecologanolic acid ( 2) and 7-ketologanin ( 3). The chemical structure of the compounds was established based on NMR, IR, and MS spectroscopic data. [ABSTRACT FROM AUTHOR]

15-Deoxy-Δ12,14-prostaglandin J2(15d-PGJ2), a representative J-series cyclopentenone prostaglandin, has biphasic roles in cell proliferation and apoptosis. Hypoxia inducible factor-1 (HIF-1) regulates expression of various genes involved in tumor growth and angiogenesis. In the present study, treatment of human breast cancer (MCF-7) cells with 15d-PGJ2resulted in the accumulation of the α-subunit of HIF-1. Pretreatment with zinc protoporphyrin IX, a pharmacological inhibitor of heme oxygenase-1 (HO-1), as well as siRNA knockdown ofHO-1gene in MCF-7 cells attenuated 15d-PGJ2-mediated HIF-1α accumulation. 15d-PGJ2treatment increased intracellular production of reactive oxygen species (ROS), which was mediated by HO-1 induction. Preincubation of MCF-7 cells with trolox, a water-soluble form of vitamin E, attenuated 15d-PGJ2-induced HIF-1α expression although HO-1 expression was unchanged. This finding suggests that ROS accumulated as a consequence of HO-1 up-regulation can enhance HIF-1α expression in MCF-7 cells treated with 15d-PGJ2. Alternatively, 15d-PGJ2was found to covalently bind to HIF-1α prolyl-4-hydroxylase 2 (PHD2) in MCF-7 cells, which hampers the proline hydroxylation of HIF-1α, thereby disrupting ubiquitin-dependent proteasomal degradation of this transcription factor. Pretreatment with thiol reducing agents blunted 15d-PGJ2-induced HIF-1α stabilization, indicative of a cysteine residue as a direct target of 15d-PGJ2. Molecular docking analysis suggests that 15d-PGJ2preferentially binds to PHD2 in the vicinity of the Cys201residue based on binding energies and carbon–sulfur distances. In summary, 15d-PGJ2stabilizes HIF-1α in MCF-7 cells through HO-1 induction with subsequent ROS generation and also through direct modification of PHD2. [ABSTRACT FROM AUTHOR]

One new phenylglycoside, 1-hydroxy-3,4,5-trimethoxyphenyl-1-O-[6′-O-(4″-carboxy-1″ ,3″ ,5″ - trihydroxy)phenyl]-β-D-glucopyranoside ( 1), along with eight known ones, isosalicin ( 2), vanilloloside ( 3), (4-hydroxy-3,5-dimethoxyphenyl)methyl-β-D-glucopyranoside ( 4), crenatin ( 5), hydrageifolin I ( 6), tachioside ( 7), isotachioside ( 8), and koaburside ( 9), were isolated from the stems of Spiraea prunifolia var. simpliciflora. The chemical structures of these compounds were identified on the basis of spectroscopic data such as NMR, FAB-MS, and IR. All these compounds were isolated from this plant for the first time. [ABSTRACT FROM AUTHOR]

A new lignan, (7′ S,8 S,8′ S)-3,5′-dimethoxy-3′,4,9′-trihydroxy-7′,9-epoxy-8,8′-lignan, named vibruresinol ( 1), was isolated from the stems of Viburnum erosum by silica gel, ODS, and Sephadex LH-20 column chromatography. In addition, four other known lignans, (7′ R,8 S,8′ S)-3,5′-dimethoxy-3′,4,8′,9′-tetrahydroxy-7′,9-epoxy-8,8′-lignan ( 2), (+)-syringaresinol ( 3), (+)-pinoresinol ( 4), and (+)-pinoresinol-4- O- β- d-glucopyranoside ( 5), and five known neolignans, herpetol ( 6), vibsanol ( 7), (−)-dehydrodiconiferyl alcohol ( 8), icariside E ( 9), and dihydrodehydrodiconiferyl alcohol ( 10), were isolated in the same manner. The chemical structures of the compounds were determined based on spectroscopic data including NMR, MS, and IR. All of the compounds described above were isolated from V. erosum for the first time. The isolated compounds 3, 4, and 6 were evaluated for neuroprotective activity on glutamate-induced cell death in HT22 cells and had EC values of 6.33 ± 1.22, 6.96 ± 0.65, and 9.15 ± 0.36 μM, respectively. Likewise, the same compounds had inhibitory activity on NO production in LPS-induced RAW 264.7 cells with IC values of 8.30 ± 1.56, 7.89 ± 1.22, and 9.32 ± 0.36 μM, respectively. [ABSTRACT FROM AUTHOR]

The stem wood of Machilus japonica Siebold & Zucc were extracted with 80 % aqueous MeOH, and the concentrated extract was successively partitioned with ethyl acetate (EtOAc), normal butanol, and water. From the EtOAc fraction, five procyanidins, procyanidin A1 ( 1), procyanidin A2 ( 2), procyanidin B7 ( 3), cinnamtannin B1 ( 4), and aesculitannin B ( 5), were isolated. Their chemical structures were identified through spectroscopic data analyses including NMR, MS, and IR. This is the first time any of these compounds have been isolated from this plant. The compounds were evaluated for inhibition activity on LDL oxidation. All of these compounds and the positive control, BHT, showed a very high inhibition effect with IC values of 0.94, 2.1, 1.8, 1.1, 1.0, and 1.9 μM, respectively. [ABSTRACT FROM AUTHOR]

Two new iridoids were isolated and identified to three known ones, namely, loganic acid ( 2), sweroside ( 3), and 7- O-tigloylsecologanol ( 4), from the stems of Viburnum erosum. Dried stems of V. erosum were extracted with 80% methanol (MeOH), and the concentrated extract was partitioned successively with ethyl acetate (EtOAc), n-butyl alcohol ( n-BuOH), and H2O. Five compounds were isolated after repeated silica gel (SiO2), octadecyl SiO2 (ODS), and Sephadex LH-20 column chromatography of the EtOAc fraction. The chemical structures of the compounds were determined based on spectroscopic data from 1H- and 13C-NMR, DEPT, and 2D-NMR (gCOSY, gHSQC, gHMBC) data. The new iridoids were identified as 3,7-dihydroxy-8-methyl-cyclopenta[ c]pyran-4-carboxylic acid ( 1) and rel-(1 S,5 R,9 S)-9-ethenyl-1-( β-D-glucopyrinosyloxy)-5,9-dihydro-5-{2-[(2-methylbut-2-enoyl)oxy]ethyl}-1 H-pyran-4-carboxylic acid ( 5) and named viburnin and epi-7- O-tigloylsecologanolic acid, respectively. This is the first report of the isolation of these five iridoids from V. erosum. [ABSTRACT FROM AUTHOR]

Column chromatographic technology was applied to isolate six purified ursane triterpenoids from the calyx of Fragaria ananassa and they were identified on the basis of spectroscopic methods to be ursolic acid (1), pomolic acid (2), 2-oxo-pomolic acid (3), 3-O-acetyl pomolic acid (4), fupenzic acid (5) and euscaphic acid (6). This is the first study in which these compounds have been isolated from the calyx of F. ananassa. Compared to a well-known inhibitor, α-arbutin, compounds 2–6 showed a significant decrease in intracellular melanin content in B16-F10 cells, and in culture media melanin. [ABSTRACT FROM AUTHOR]

Summary: The inflammatory microenvironment promotes skin tumorigenesis. However, the mechanisms by which cells protect themselves from inflammatory signals are unknown. Downregulation of IKKα promotes skin tumor progression from papillomas to squamous cell carcinomas, which is frequently accompanied by genomic instability, including aneuploid chromosomes and extra centrosomes. In this study, we found that IKKα promoted oligomerization of nucleophosmin (NPM), a negative centrosome duplication regulator, which further enhanced NPM and centrosome association, inhibited centrosome amplification, and maintained genome integrity. Levels of NPM hexamers and IKKα were conversely associated with skin tumor progression. Importantly, proinflammatory cytokine-induced IKKα activation promoted the formation of NPM oligomers and reduced centrosome numbers in mouse and human cells, whereas kinase-dead IKKα blocked this connection. Therefore, our findings suggest a mechanism in which an IKKα-NPM axis may use inflammatory signals to suppress centrosome amplification, promote genomic integrity, and prevent tumor progression. [Copyright &y& Elsevier]

Silent mating type information regulation 1 (Sirtuin 1; SIRT1) has been reported to regulate various physiological events, such as aging and metabolism, via deacetylation of histone and nonhistone proteins. Notably, cumulative evidence supports the notion that SIRT1 has a Janus-faced role in tumorigenesis. SIRT1 contributes to anti-inflammation, genomic stability, and cancer cell death, and hence it has tumor-suppressor properties. On the other hand, SIRT1 can stimulate oncogenic signaling pathways and can create a tumor microenvironment favorable to growth and survival of cancer cells. Such dual functions of SIRT1 may be determined, at least in part, by its subcellular localization. Interestingly, SIRT1 displays differential localization in normal cells and cancer cells, which in turn may affect the substrate specificity for its deacetylase activity. [ABSTRACT FROM AUTHOR]

Six flavonoid glycosides were isolated from the n-butanol fraction of cowpea seeds ( Vigna sinensis K.) through silica gel (SiO) and octadecyl silica gel (ODS) column chromatographies. Based on their chemical structures determined via interpretation of spectroscopic data including NMR, MS, and IR, the compounds were identified as kaempferol 3- O-β- d-sophoroside ( 1), quercetin 3- O-β- d-sophoroside ( 2), isoquercitrin ( 3), hyperin ( 4), catechin 7- O-β- d-glucopyranoside ( 5), and quercetin 3- O-β-Dglucopyranosyl( 1→6)- O-β- d-galactopyranoside ( 6). This is the first report of the isolation of these flavonoids from this plant. Among these flavonoids, compound 2, 5, and 6 significantly inhibited LDL oxidation exhibiting 96.0±0.1 (IC: 3.9 μM), 96.8±1.7 (IC: 2.9 μM), and 97.4±0.1% (IC: 3.5 μM) inhibition, respectively, at a concentration of 40 μM. [ABSTRACT FROM AUTHOR]

Simple Summary: Microbiota dysbiosis is correlated with numerous diseases in the human body. To date, the research on the microbiome-associated diseases been focused on an organ-specific microbiome. However, the interorgan microbial network is emerging as an important regulator in physiological functions and pathological processes. The oral cavity and gut are the two largest microbial ecosystems. Recent studies have demonstrated that the oral-to-gut and gut-to-oral microbial transmission can regulate pathogenesis, indicating the presence of the oral–gut microbiome axis. Here, we will review the role of the oral–gut microbiome axis in gastrointestinal disease and cancer, which may provide insight for precise diagnosis/prognosis and effective treatment. It is well-known that microbiota dysbiosis is closely associated with numerous diseases in the human body. The oral cavity and gut are the two largest microbial habitats, playing a major role in microbiome-associated diseases. Even though the oral cavity and gut are continuous regions connected through the gastrointestinal tract, the oral and gut microbiome profiles are well-segregated due to the oral–gut barrier. However, the oral microbiota can translocate to the intestinal mucosa in conditions of the oral–gut barrier dysfunction. Inversely, the gut-to-oral microbial transmission occurs as well in inter- and intrapersonal manners. Recently, it has been reported that oral and gut microbiomes interdependently regulate physiological functions and pathological processes. Oral-to-gut and gut-to-oral microbial transmissions can shape and/or reshape the microbial ecosystem in both habitats, eventually modulating pathogenesis of disease. However, the oral–gut microbial interaction in pathogenesis has been underappreciated to date. Here, we will highlight the oral–gut microbiome crosstalk and its implications in the pathogenesis of the gastrointestinal disease and cancer. Better understanding the role of the oral–gut microbiome axis in pathogenesis will be advantageous for precise diagnosis/prognosis and effective treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: Signal transducer and activator of transcription 3 (STAT3) and nuclear factor-κB (NF-κB) play a cooperative role in inflammation-associated tumorigenesis at multi-levels. The α subunit of the inhibitor of the κB kinase (IKK) complex, IKKα, is involved in both classical and non-classical activation of NF-κB. However, the interplay between STAT3 and IKKα has not been clarified yet. Here, we report overexpression and co-localization of IKKα and STAT3 in human breast cancer tissues as well as in human breast cancer cells, which promotes breast cancer promotion and progression. IKKα was stabilized and upregulated by STAT3. We identified the lysine 44 residue of IKKα as a putative binding site for STAT3. Taken together, these findings propose a novel mechanism responsible for NF-κB activation by STAT3 through stabilization of IKKα. Thus, STAT3 and IKKα could integrate, and coordinately mediate the growth and progression of human breast cancer. Signal transducer and activator of transcription 3 (STAT3) and nuclear factor-κB (NF-κB) are two representative transcription factors that play a critical role in inflammation-associated tumorigenesis through multi-level cooperation. Unlike other types of tumors, breast carcinomas have shown a significant dependency on the non-classical NF-κB pathway as well as the classical one. The α subunit of the inhibitor of the κB kinase (IKK) complex, IKKα, is involved in both classical and non-classical activation of NF-κB. Although the cross-talk between STAT3 and NF-κB has been suggested in several studies, the interplay between STAT3 and the regulators of NF-κB including IKKα has not been fully clarified yet. In this study, we observed overexpression and co-localization of IKKα and STAT3 in human breast cancer tissues as well as in H-Ras transformed human breast epithelial (H-Ras MCF-10A) and breast cancer (MDA-MB-231) cells. By utilizing small interfering RNA (siRNA) technology, we were able to demonstrate that STAT3 up-regulated IKKα, but not IKKβ or IKKγ, in these cells. This was attributable to direct binding to and subsequent stabilization of IKKα protein by blocking the ubiquitin-proteasome system. Notably, we identified the lysine 44 residue of IKKα as a putative binding site for STAT3. Moreover, siRNA knockdown of IKKα attenuated viability, anchorage-independent growth and migratory capabilities of H-Ras MCF-10A cells. Taken together, these findings propose a novel mechanism responsible for NF-κB activation by STAT3 through stabilization of IKKα, which contributes to breast cancer promotion and progression. Thus, breaking the STAT3-IKKα alliance can be an alternative therapeutic strategy for the treatment of breast cancer. [ABSTRACT FROM AUTHOR]

Chemerin is secreted as prochemerin from various cell types and then cleaved into the bioactive isoform by specific proteases. In various cancer types, chemerin exhibits pro- or antitumor effects. In the present study, chemerin treatment significantly inhibited the viability and invasion of breast cancer cells in the absence or presence of transforming growth factor (TGF)-β and insulin-like growth factor (IGF)-1. The expression levels of E-cadherin and vimentin were reduced in chemerin-treated breast cancer cells. However, chemerin treatment recovered the reduced E-cadherin expression level in breast cancer cells treated with TGF-β or IGF-1. Chemerin treatment inhibited nuclear β-catenin levels in breast cancer cells stimulated with or without TGF-β or IGF-1. In addition, chemerin treatment blocked the increase in the receptor activator of nuclear factor kappa-Β ligand (RANKL)/osteoprotegerin (OPG) ratio in osteoblastic cells exposed to metastatic breast cancer cell-derived conditioned medium. Chemerin treatment inhibited RANKL-induced osteoclast formation and bone resorption by reducing the secretion of matrix metalloproteinase (MMP)-2, MMP-9, and cathepsin K. Intraperitoneal administration of chemerin inhibited tumor growth in MCF-7 breast cancer cell-injected mice and reduced the development of osteolytic lesions resulting from intratibial inoculation of MDA-MB-231 cells. Taken together, chemerin inhibits the growth and invasion of breast cancer cells and prevents bone loss resulting from breast cancer cells by inhibiting finally osteoclast formation and activity. [ABSTRACT FROM AUTHOR]

The role of Situin 1 (SIRT1) in tumorigenesis is still controversial due to its wide range of substrates, including both oncoproteins and tumor suppressors. A recent study has demonstrated that SIRT1 interferes in the Kirsten rat sarcoma viral oncogene homolog (KRAS)-driven activation of the Raf-mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK pathway, thereby inhibiting tumorigenesis. However, the molecular mechanism of SIRT1 as a tumor suppressor in RAS-driven tumorigenesis has been less clearly determined. This study presents evidence that the ectopic expression of SIRT1 attenuates RAS- or MEK-driven ERK activation and reduces cellular proliferation and transformation in vitro. The attenuation of ERK activation by SIRT1 results from prompt dephosphorylation of ERK, while MEK activity remains unchanged. We identified that MKP1, a dual specific phosphatase for MAPK, was deacetylated by SIRT1. Deacetylation of MKP1 by direct interaction with SIRT1 increased the binding affinity to ERK which in turn facilitated inactivation of ERK. Taken together, these results suggest that SIRT1 would act as a tumor suppressor by modulating RAS-driven ERK activity through MKP1 deacetylation. [ABSTRACT FROM AUTHOR]

Even when targets responsible for chemoresistance are identified, drug development is often hampered due to the poor druggability of these proteins. We systematically analyzed therapy-resistance with a large-scale cancer cell transcriptome and drug-response datasets and predicted the candidate drugs based on the gene expression profile. Our results implicated the epithelial–mesenchymal transition as a common mechanism underlying resistance to chemotherapeutic drugs. Notably, we identified ITGB3, whose expression was abundant in both drug resistance and mesenchymal status, as a promising target to overcome chemoresistance. We also confirmed that depletion of ITGB3 sensitized cancer cells to conventional chemotherapeutic drugs by modulating the NF-κB signaling pathway. Considering the poor druggability of ITGB3 and the lack of feasible drugs to directly inhibit this protein, we took an in silico screening for drugs mimicking the transcriptome-level changes caused by knockdown of ITGB3. This approach successfully identified atorvastatin as a novel candidate for drug repurposing, paving an alternative path to drug screening that is applicable to undruggable targets. [ABSTRACT FROM AUTHOR]