Causes and consequences of increased glucose metabolism of cancers

Glucose metabolic rate from four-dimensional [18F]FDG PET/CT to differentiate sarcoid lesions from malignant lesions

OBJECTIVES

On 18F-Fludeoxyglucose (FDG) PET/CT, active sarcoid lesions are often difficult to differentiate from malignant lesions. We investigated the potential of the glucose metabolic rate (MRglc, mg/min/100 mL), a new quantification of glucose metabolic kinetics derived from direct reconstruction based on linear Patlak analysis, to distinguish between sarcoidosis and malignant lesions.

MATERIALS AND METHODS

A total of 100 patients with cardiac sarcoidosis (CS) and 67 patients with cancer who underwent four-dimensional FDG PET/CT were enrolled. The lesions with a standardized uptake value (SUV) ≥ 2.7 on the standard scan were included as active lesions in the analysis. SUV and MRglc were derived using data acquired between 30 min and 50 min on four-dimensional FDG PET/CT. The mean value in the volume of interest (size 1.5 cm3) was measured. The diagnostic performance of sarcoidosis using MRglc and SUV was evaluated using receiver-operating-characteristic (ROC) analysis.

RESULTS

A total of 90 sarcoidosis lesions from 44 CS patients (18 males, 63.4 ± 12.2 years) and 87 malignant lesions from 57 cancer-bearing patients (32 males, 65 ± 14 years) were analyzed. SUV and MRglc for sarcoid lesions were significantly lower than those for malignant lesions (SUV, 4.98 ± 2.00 vs 6.21 ± 2.14; MRglc, 2.52 ± 1.39 vs 3.68 ± 1.61; p < 0.01). ROC analysis indicated that the ability to discriminate sarcoid patients from those with malignancy yielded areas under the curves of 0.703 and 0.754, with sensitivities of 64% and 77% and specificities of 75% and 72% for SUV 5.025 and MRglc 2.855, respectively.

CONCLUSION

MRglc was significantly lower in sarcoid lesions than malignant lesions, and improved sarcoid lesions identification over SUV alone.

CLINICAL RELEVANCE STATEMENT

MRglc improves sarcoid lymph node identification over SUV alone and is expected to shorten the examination time by eliminating delayed scans.

KEY POINTS

Active sarcoid lesions are sometimes associated with FDG accumulation and should be differentiated from malignant lesions. SUV and metabolic rate of glucose (MRglc) strongly positively correlated, and MRglc could differentiate sarcoid and malignant lesions. MRglc allows for accurate evaluation and staging of malignant lesions.

Pharmacological Activation of SIRT3 Modulates the Response of Cancer Cells to Acidic pH

Cancer cells modulate their metabolism, creating an acidic microenvironment that, in turn, can favor tumor progression and chemotherapy resistance. Tumor cells adopt strategies to survive a drop in extracellular pH (pHe). In the present manuscript, we investigated the contribution of mitochondrial sirtuin 3 (SIRT3) to the adaptation and survival of cancer cells to a low pHe. SIRT3-overexpressing and silenced breast cancer cells MDA-MB-231 and human embryonic kidney HEK293 cells were grown in buffered and unbuffered media at pH 7.4 and 6.8 for different times. mRNA expression of SIRT3 and CAVB, was measured by RT-PCR. Protein expression of SIRT3, CAVB and autophagy proteins was estimated by western blot. SIRT3-CAVB interaction was determined by immunoprecipitation and proximity ligation assays (PLA). Induction of autophagy was studied by western blot and TEM. SIRT3 overexpression increases the survival of both cell lines. Moreover, we demonstrated that SIRT3 controls intracellular pH (pHi) through the regulation of mitochondrial carbonic anhydrase VB (CAVB). Interestingly, we obtained similar results by using MC2791, a new SIRT3 activator. Our results point to the possibility of modulating SIRT3 to decrease the response and resistance of tumor cells to the acidic microenvironment and ameliorate the effectiveness of anticancer therapy.

Collagen density regulates tip-stalk cell rearrangement during angiogenesis via cellular bioenergetics

Tumor vasculature plays a crucial role in tumor progression, affecting nutrition and oxygen transportation as well as the efficiency of drug delivery. While targeting pro-angiogenic growth factors has been a significant focus for treating tumor angiogenesis, recent studies indicate that metabolism also plays a role in regulating endothelial cell behavior. Like cancer cells, tumor endothelial cells undergo metabolic changes that regulate rearrangement for tip cell position during angiogenesis. Our previous studies have shown that altered mechanical properties of the collagen matrix regulate angiogenesis and can promote a tumor vasculature phenotype. Here, we examine the effect of collagen density on endothelial cell tip-stalk cell rearrangement and cellular energetics during angiogenic sprouting. We find that increased collagen density leads to an elevated energy state and an increased rate of tip-stalk cell switching, which is correlated with the energy state of the cells. Tip cells exhibit higher glucose uptake than stalk cells, and inhibition of glucose uptake revealed that invading sprouts rely on glucose to meet elevated energy requirements for invasion in dense matrices. This work helps to elucidate the complex interplay between the mechanical microenvironment and the endothelial cell metabolic status during angiogenesis, which could have important implications for developing new anti-cancer therapies.

Targeting glutamine metabolism improves sarcoma response to radiation therapy in vivo

Diverse tumor metabolic phenotypes are influenced by the environment and genetic lesions. Whether these phenotypes extend to rhabdomyosarcoma (RMS) and how they might be leveraged to design new therapeutic approaches remains an open question. Thus, we utilized a Pax7Cre-ER-T2/+; NrasLSL-G12D/+; p53fl/fl (P7NP) murine model of sarcoma with mutations that most frequently occur in human embryonal RMS. To study metabolism, we infuse 13C-labeled glucose or glutamine into mice with sarcomas and show that sarcomas consume more glucose and glutamine than healthy muscle tissue. However, we reveal a marked shift from glucose consumption to glutamine metabolism after radiation therapy (RT). In addition, we show that inhibiting glutamine, either through genetic deletion of glutaminase (Gls1) or through pharmacological inhibition of glutaminase, leads to significant radiosensitization in vivo. This causes a significant increase in overall survival for mice with Gls1-deficient compared to Gls1-proficient sarcomas. Finally, Gls1-deficient sarcomas post-RT elevate levels of proteins involved in natural killer cell and interferon alpha/gamma responses, suggesting a possible role of innate immunity in the radiosensitization of Gls1-deficient sarcomas. Thus, our results indicate that glutamine contributes to radiation response in a mouse model of RMS.

Prevalence of high-risk human papillomavirus infection among women with diabetes mellitus in Accra, Ghana

BACKGROUND

There is increasing evidence of a higher risk and poorer prognosis of cervical cancer among women with diabetes mellitus (DM) compared to the general population. These are mediated by higher susceptibility to persistent high-risk human papillomavirus (hr-HPV) infection due to dysfunctional clearance in an immunocompromised state. We aimed to determine the prevalence of hr-HPV infection and cervical lesions in a cohort of women with DM in Ghana. We further disaggregated the prevalence according to DM type and explored factors associated with hr-HPV infection.

METHODS

This retrospective descriptive cross-sectional study assessed 198 women with DM who underwent cervical screening via concurrent hr-HPV DNA testing and visual inspection with acetic acid in an outpatient department of the National Diabetes Management and Research Centre in Korle-Bu Teaching Hospital, Accra from March to May 2022. Univariate and multivariable binary logistic regression were used to explore factors associated with hr-HPV positivity.

RESULTS

Among 198 women with DM (mean age, 60.2 ± 12.1 years), the overall hr-HPV prevalence rate was 21.7% (95% CI, 16.1-28.1), disaggregated as 1.5% (95% CI, 0.3-4.4) each for HPV16 and HPV18 and 20.7% (95% CI, 15.3-27.0) for other HPV genotype(s). Respective hr-HPV prevalence rates were 37.5% (95% CI, 15.2-64.6) for type 1 DM, 19.8% (95% CI, 13.9-26.7) for type 2 DM, and 25.0% (95% CI, 8.7-49.1) for unspecified/other DM types. Past use of the combined contraceptive pill independently increased the risk of hr-HPV infection by approximately three times (adjusted odds ratio [aOR] = 2.98; 95% CI, 1.03 - 8.64; p-value = 0.045), whereas each unit increase in FBG level increased the odds of hr-HPV infection by about 15% (aOR = 1.15; 95% CI, 1.02 - 1.30; p-value = 0.021).

CONCLUSION

Our study points to a high prevalence of hr-HPV among women with DM and highlights a need for glycemic control among them as this could contribute to lowering their odds of hr-HPV infection. The low overall rates of HPV vaccination and prior screening also indicate a need to build capacity and expand the scope of education and services offered to women with DM as regards cervical precancer screening.

Application of metabolomics in oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a prevalent malignancy affecting the head and neck region. The prognosis for OSCC patients remains unfavorable due to the absence of precise and efficient early diagnostic techniques. Metabolomics offers a promising approach for identifying distinct metabolites, thereby facilitating early detection and treatment of OSCC.

OBJECTIVE

This review aims to provide a comprehensive overview of recent advancements in metabolic marker identification for early OSCC diagnosis. Additionally, the clinical significance and potential applications of metabolic markers for the management of OSCC are discussed.

RESULTS

This review summarizes metabolic changes during the occurrence and development of oral squamous cell carcinoma and reviews prospects for the clinical application of characteristic, differential metabolites in saliva, serum, and OSCC tissue. In this review, the application of metabolomic technology in OSCC research was summarized, and future research directions were proposed.

CONCLUSION

Metabolomics, detection technology that is the closest to phenotype, can efficiently identify differential metabolites. Combined with statistical data analyses and artificial intelligence technology, it can rapidly screen characteristic biomarkers for early diagnosis, treatment, and prognosis evaluations.

Patlak Reconstruction Using Dynamic 18 F-FDG PET Imaging for Evaluation of Malignant Liver Tumors : A Comparison of HCC, ICC, and Metastatic Liver Tumors

PURPOSE OF THE REPORT

The aim of this study was to explore the different patterns of dynamic whole-body (D-WB) FDG PET/CT parameters among liver malignancy types as potential diagnostic clues and investigate the association between static and dynamic PET/CT parameters for each tumor histology.

PATIENTS AND METHODS

Seventy-one patients with intrahepatic cholangiocarcinoma (ICC), metastatic liver tumor (MLT), or hepatocellular carcinoma (HCC) who underwent D-WB and static dual-time-point FDG PET/CT were enrolled. We obtained Pearson correlation coefficients between the metabolic rate of FDG (MR FDG ; mg/min/ 100ml) or distribution volume of free FDG (DV FDG , %) and static PET/CT parameters. We compared MR FDG and DV FDG values by tumor type and performed receiver operating characteristic analyses for MR FDG and static images.

RESULTS

A total of 12 ICC, 116 MLT, and 36 HCC lesions were analyzed. MR FDG and DV FDG showed excellent correlation with early (SUV e ) and delayed SUV max (SUV d ) ( r = 0.71~0.97), but DV FDG in the HCC lesions did not ( r = 0.62 and 0.69 for SUV e and SUV d , respectively) ( P < 0.001 for all). HCC lesions showed significantly lower MR FDG (2.43 ± 1.98) and DV FDG (139.95 ± 62.58) than ICC (5.02 ± 3.56, 207.06 ± 97.13) and MLT lesions (4.51 ± 2.47, 180.13 ± 75.58) ( P < 0.01 for all). The optimal MR FDG could differentiate HCC from ICC and MLT with areas under the curve of 0.84 and 0.80, respectively. Metastatic liver tumor lesions showed the widest distribution of MR FDG and DV FDG values but with no significant difference among most primary sites.

CONCLUSIONS

MR FDG was strongly correlated with SUV max in the 3 malignancies and showed utility for differentiating HCC from ICC and MLT. Each tumor type has a different glucose metabolism, and D-WB FDG PET/CT imaging has the potential to visualize those differences.

Distinct FDG PET/CT avidity among newly diagnosed intravascular large B-cell lymphoma patients: a descriptive observational study

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of aggressive B-cell non-Hodgkin lymphoma that poses a great diagnostic challenge due to its highly heterogenous clinical manifestations. Although 18F-fluorodeoxyglucose (FDG) is widely used as a diagnostic tool for patients suspected of having lymphoma, as it reveals FDG-avid lesions, the FDG avidity of IVLBCL has not been extensively characterized. Here, we present a comprehensive report of FDG avidity in IVLBCL and its association with clinicopathological features and survival. This descriptive observational study included consecutive patients aged at least 18 years diagnosed with IVLBCL in Peking Union Medical Hospital across 9 years. Among 50 screened IVLBCL patients, 42 had undergone 18F-FDG PET/CT to detect possible lesions for biopsy before pathological diagnosis; their FDG PET/CT (positron emission computed tomography, PET/CT) reports were retrospectively reviewed. The primary endpoint was the clinical description of FDG avidity of newly diagnosed intravascular large B-cell lymphoma and frequency. A total of 73.8% patients showed FDG-avid lesions, with a median SUVmax of 7.4 (range 1-27.7), which was lower than that for other aggressive lymphomas. Clinicopathological features were the same between the FDG-avid group and the non-FDG-avid group, except that the latter had a higher Ki-67 index (median 90% in the nonavid group vs. 80% in the avid group, P = 0.043). The overall survival rate was not different between the PET/CT groups. Our findings demonstrate that FDG PET/CT is a useful diagnostic tool for detecting FDG-avid lesions in IVLBCL patients. A random skin biopsy is essential for assisting in the diagnosis of IVLBCL, even for those with negative PET/CT.

Unlocking the potential of amorphous calcium carbonate: A star ascending in the realm of biomedical application

Calcium-based biomaterials have been intensively studied in the field of drug delivery owing to their excellent biocompatibility and biodegradability. Calcium-based materials can also deliver contrast agents, which can enhance real-time imaging and exert a Ca2+-interfering therapeutic effect. Based on these characteristics, amorphous calcium carbonate (ACC), as a brunch of calcium-based biomaterials, has the potential to become a widely used biomaterial. Highly functional ACC can be either discovered in natural organisms or obtained by chemical synthesis However, the standalone presence of ACC is unstable in vivo. Additives are required to be used as stabilizers or core-shell structures formed by permeable layers or lipids with modified molecules constructed to maintain the stability of ACC until the ACC carrier reaches its destination. ACC has high chemical instability and can produce biocompatible products when exposed to an acidic condition in vivo, such as Ca2+ with an immune-regulating ability and CO2 with an imaging-enhancing ability. Owing to these characteristics, ACC has been studied for self-sacrificing templates of carrier construction, targeted delivery of oncology drugs, immunomodulation, tumor imaging, tissue engineering, and calcium supplementation. Emphasis in this paper has been placed on the origin, structural features, and multiple applications of ACC. Meanwhile, ACC faces many challenges in clinical translation, and long-term basic research is required to overcome these challenges. We hope that this study will contribute to future innovative research on ACC.

PI3K/AKT signaling activates HIF1α to modulate the biological effects of invasive breast cancer with microcalcification

Microcalcification (MC) is a valuable diagnostic indicator of breast cancer, and it is reported to be associated with increased tumor aggressiveness and poor prognosis. Nevertheless, the exact potential molecular mechanism is not completely understood. Here, we find that the mineralized invasive breast cancer (IBC) cells not only increased their proliferation and migration, but also showed the characteristic of doxorubicin resistance. The PI3K/AKT signaling pathway is associated with the generation of calcification in IBC, and it activates the transcription and translation of its downstream hypoxia-inducible factor 1α (HIF1α). Knockdown of HIF1α protein significantly downregulated cell proliferation and migration while calcification persists. Meanwhile, calcified breast cancer cells restored sensitivity to doxorubicin because of suppressed HIF1α expression. In addition, we provide initial data on the underlying value of HIF1α as a biomarker of doxorubicin resistance. These findings provide a new direction for exploring microcalcifications in IBC.

Targeting Glucose Metabolism in Cancer Cells as an Approach to Overcoming Drug Resistance

The "Warburg effect" consists of a metabolic shift in energy production from oxidative phosphorylation to glycolysis. The continuous activation of glycolysis in cancer cells causes rapid energy production and an increase in lactate, leading to the acidification of the tumour microenvironment, chemo- and radioresistance, as well as poor patient survival. Nevertheless, the mitochondrial metabolism can be also involved in aggressive cancer characteristics. The metabolic differences between cancer and normal tissues can be considered the Achilles heel of cancer, offering a strategy for new therapies. One of the main causes of treatment resistance consists of the increased expression of efflux pumps, and multidrug resistance (MDR) proteins, which are able to export chemotherapeutics out of the cell. Cells expressing MDR proteins require ATP to mediate the efflux of their drug substrates. Thus, inhibition of the main energy-producing pathways in cancer cells, not only induces cancer cell death per se, but also overcomes multidrug resistance. Given that most anticancer drugs do not have the ability to distinguish normal cells from cancer cells, a number of drug delivery systems have been developed. These nanodrug delivery systems provide flexible and effective methods to overcome MDR by facilitating cellular uptake, increasing drug accumulation, reducing drug efflux, improving targeted drug delivery, co-administering synergistic agents, and increasing the half-life of drugs in circulation.

Unlocking the potential of the tumor microenvironment for cancer therapy

The tumor microenvironment (TME) holds a crucial role in the progression of cancer. Epithelial-derived tumors share common traits in shaping the TME. The Warburg effect is a notable phenomenon wherein tumor cells exhibit resistance to apoptosis and an increased reliance on anaerobic glycolysis for energy production. Recognizing the pivotal role of the TME in controlling tumor growth and influencing responses to chemotherapy, researchers have focused on developing potential cancer treatment strategies. A wide array of therapies, including immunotherapies, antiangiogenic agents, interventions targeting cancer-associated fibroblasts (CAF), and therapies directed at the extracellular matrix, have been under investigation and have demonstrated efficacy. Additionally, innovative techniques such as tumor tissue explants, "tumor-on-a-chip" models, and multicellular tumor spheres have been explored in laboratory research. This comprehensive review aims to provide insights into the intricate cross-talk between cancer-associated signaling pathways and the TME in cancer progression, current therapeutic approaches targeting the TME, the immune landscape within solid tumors, the role of the viral TME, and cancer cell metabolism.

Calculation of ATP production rates using the Seahorse XF Analyzer

Oxidative phosphorylation and glycolysis are the dominant ATP-generating pathways in mammalian metabolism. The balance between these two pathways is often shifted to execute cell-specific functions in response to stimuli that promote activation, proliferation, or differentiation. However, measurement of these metabolic switches has remained mostly qualitative, making it difficult to discriminate between healthy, physiological changes in energy transduction or compensatory responses due to metabolic dysfunction. We therefore present a broadly applicable method to calculate ATP production rates from oxidative phosphorylation and glycolysis using Seahorse XF Analyzer data and empirical conversion factors. We quantify the bioenergetic changes observed during macrophage polarization as well as cancer cell adaptation to in vitro culture conditions. Additionally, we detect substantive changes in ATP utilization upon neuronal depolarization and T cell receptor activation that are not evident from steady-state ATP measurements. This method generates a single readout that allows the direct comparison of ATP produced from oxidative phosphorylation and glycolysis in live cells. Additionally, the manuscript provides a framework for tailoring the calculations to specific cell systems or experimental conditions.

A PD-L1 Antibody-Conjugated PAMAM Dendrimer Nanosystem for Simultaneously Inhibiting Glycolysis and Promoting Immune Response in Fighting Breast Cancer

Breast cancer is the most frequent malignancy affecting women, yet current therapeutic strategies remain ineffective for patients with late-stage or metastatic disease. Here an effective strategy is reported for treating metastatic breast cancer. Specifically, a self-assembling dendrimer nanosystem decorated with an antibody against programmed cell death ligand 1 (PD-L1) is established for delivering a small interfering RNA (siRNA) to target 3-phosphoinositide-dependent protein kinase-1 (PDK1), a kinase involved in cancer metabolism and metastasis. This nanosystem, named PPD, is designed to target PD-L1 for cancer-specific delivery of the siRNA to inhibit PDK1 and modulate cancer metabolism while promoting programmed cell death 1 (PD-1)/PD-L1 pathway-based immunotherapy. Indeed, PPD effectively generates simultaneous inhibition of PDK1-induced glycolysis and the PD-1/PD-L1 pathway-related immune response, leading to potent inhibition of tumor growth and metastasis without any notable toxicity in tumor-bearing mouse models. Collectively, these results highlight the potential use of PPD as an effective and safe tumor-targeting therapy for breast cancer. This study constitutes a successful proof of principle exploiting the intrinsic features of the tumor microenvironment and metabolism alongside a unique self-assembling dendrimer platform to achieve specific tumor targeting and siRNA-based gene silencing in combined and precision cancer therapy.

Photoactive Parietin-loaded nanocarriers as an efficient therapeutic platform against triple-negative breast cancer

The application of photodynamic therapy has become more and more important in combating cancer. However, the high lipophilic nature of most photosensitizers limits their parenteral administration and leads to aggregation in the biological environment. To resolve this problem and deliver a photoactive form, the natural photosensitizer parietin (PTN) was encapsulated in poly(lactic-co-glycolic acid) nanoparticles (PTN NPs) by emulsification diffusion method. PTN NPs displayed a size of 193.70 nm and 157.31 nm, characterized by dynamic light scattering and atomic force microscopy, respectively. As the photoactivity of parietin is essential for therapy, the quantum yield of PTN NPs and the in vitro release were assessed. The antiproliferative activity, the intracellular generation of reactive oxygen species, mitochondrial potential depolarization, and lysosomal membrane permeabilization were evaluated in triple-negative breast cancer cells (MDA-MB-231 cells). At the same time, confocal laser scanning microscopy (CLSM) and flow cytometry were used to investigate the cellular uptake profile. In addition, the chorioallantoic membrane (CAM) was employed to evaluate the antiangiogenic effect microscopically. The spherical monomodal PTN NPs show a quantum yield of 0.4. The biological assessment on MDA-MB-231 cells revealed that free PTN and PTN NPs inhibited cell proliferation with IC50 of 0.95 µM and 1.9 µM at 6 J/cm2, respectively, and this can be attributed to the intracellular uptake profile as proved by flow cytometry. Eventually, the CAM study illustrated that PTN NPs could reduce the number of angiogenic blood vessels and disrupt the vitality of xenografted tumors. In conclusion, PTN NPs are a promising anticancer strategy in vitro and might be a tool for fighting cancer in vivo.

IDH1 K224 acetylation promotes colorectal cancer via miR-9-5p/NHE1 axis-mediated regulation of acidic microenvironment

The acidic microenvironment is considered an important factor in colorectal cancer (CRC) that contributes to malignant transformation. However, the underlying mechanism remains unclear. In a previous study, we confirmed that IDH1 K224 deacetylation promotes enzymatic activity and the production of α-KG. Here, we further investigate the effect of IDH1 hyperacetylation on the CRC acidic microenvironment. We demonstrate that increased α-KG affects hydroxylation of Ago2 and mediates miR-9-5p targeting NHE1 protein. Knockdown of NHE1 dramatically attenuates CRC cell proliferation and migration by restricting transport of intracellular H⁺ out of cells. Furthermore, we show that miR-9-5p is the microRNA with the most significant difference in the alteration of IDH1 K224 acetylation and can downregulate NHE1 mRNA. Our data also indicate that hydroxylation stabilizes Ago2, which in turn promotes miR-9-5p activity. Taken together, our results reveal a novel mechanism through which IDH1 deacetylation regulates the cellular acidic microenvironment and inhibits CRC metastasis.

Synergistic glycolysis disturbance for cancer therapy by a MOF-based nanospoiler

Increased glycolysis for promoting adenosine triphosphate (ATP) generation is one of the hallmarks of cancer. Although reducing glucose intake or depriving cellular glucose can delay the growth of tumors to some extent, their therapeutic efficacy is a highly needed improvement for clinical translation. Herein, we found that mannose synergistic with glucose oxidase (GOx) can induce cell death by ATP inhibition, autophagy activation, and apoptosis protein upgradation. By using biodegradable zeolitic imidazolate frameworks (ZIF-8) as a nanocarrier (denoted as ZIF-8/M&G), the mannose and GOx can accumulate at the tumor site while having no obvious long-term toxicity. At the tumor site, GOx inhibits glycolysis by converting glucose and oxygen to H 2O 2 and gluconic acid, realizing oxidation therapy and expediting the degradation of the pH-responsive ZIF-8 nanoparticles, respectively. Simultaneously, mannose disturbs sugar metabolism and reduces oxygen consumption, which in turn promotes the GOx oxidation process. The concerted glycolysis inhibition through interactions between mannose and GOx endows ZIF-8/M&G nanospolier with excellent therapeutic efficacy both in vitro and in vivo. Synergistic glycolysis disturbance by the designed nanospoiler in this work proposes a versatile approach for metabolism disturbance to tumor treatment.

Functional Imaging of Hypoxia: PET and MRI

Molecular and functional imaging have critical roles in cancer care. Existing evidence suggests that noninvasive detection of hypoxia within a particular type of cancer can provide new information regarding the relationship between hypoxia, cancer aggressiveness and altered therapeutic responses. Following the identification of hypoxia inducible factor (HIF), significant progress in understanding the regulation of hypoxia-induced genes has been made. These advances have provided the ability to therapeutically target HIF and tumor-associated hypoxia. Therefore, by utilizing the molecular basis of hypoxia, hypoxia-based theranostic strategies are in the process of being developed which will further personalize care for cancer patients. The aim of this review is to provide an overview of the significance of tumor hypoxia and its relevance in cancer management as well as to lay out the role of imaging in detecting hypoxia within the context of cancer.

Synthesis and hLDH Inhibitory Activity of Analogues to Natural Products with 2,8-Dioxabicyclo[3.3.1]nonane Scaffold

Human lactate dehydrogenase (hLDH) is a tetrameric enzyme present in almost all tissues. Among its five different isoforms, hLDHA and hLDHB are the predominant ones. In the last few years, hLDHA has emerged as a therapeutic target for the treatment of several kinds of disorders, including cancer and primary hyperoxaluria. hLDHA inhibition has been clinically validated as a safe therapeutic method and clinical trials using biotechnological approaches are currently being evaluated. Despite the well-known advantages of pharmacological treatments based on small-molecule drugs, few compounds are currently in preclinical stage. We have recently reported the detection of some 2,8-dioxabicyclo[3.3.1]nonane core derivatives as new hLDHA inhibitors. Here, we extended our work synthesizing a large number of derivatives (42-70) by reaction between flavylium salts (27-35) and several nucleophiles (36-41). Nine 2,8-dioxabicyclo[3.3.1]nonane derivatives showed IC₅₀ values lower than 10 µM against hLDHA and better activity than our previously reported compound 2. In order to know the selectivity of the synthesized compounds against hLDHA, their hLDHB inhibitory activities were also measured. In particular, compounds 58, 62a, 65b, and 68a have shown the lowest IC₅₀ values against hLDHA (3.6-12.0 µM) and the highest selectivity rate (>25). Structure-activity relationships have been deduced. Kinetic studies using a Lineweaver-Burk double-reciprocal plot have indicated that both enantiomers of 68a and 68b behave as noncompetitive inhibitors on hLDHA enzyme.

Protein posttranslational modifications in health and diseases: Functions, regulatory mechanisms, and therapeutic implications

Protein posttranslational modifications (PTMs) refer to the breaking or generation of covalent bonds on the backbones or amino acid side chains of proteins and expand the diversity of proteins, which provides the basis for the emergence of organismal complexity. To date, more than 650 types of protein modifications, such as the most well-known phosphorylation, ubiquitination, glycosylation, methylation, SUMOylation, short-chain and long-chain acylation modifications, redox modifications, and irreversible modifications, have been described, and the inventory is still increasing. By changing the protein conformation, localization, activity, stability, charges, and interactions with other biomolecules, PTMs ultimately alter the phenotypes and biological processes of cells. The homeostasis of protein modifications is important to human health. Abnormal PTMs may cause changes in protein properties and loss of protein functions, which are closely related to the occurrence and development of various diseases. In this review, we systematically introduce the characteristics, regulatory mechanisms, and functions of various PTMs in health and diseases. In addition, the therapeutic prospects in various diseases by targeting PTMs and associated regulatory enzymes are also summarized. This work will deepen the understanding of protein modifications in health and diseases and promote the discovery of diagnostic and prognostic markers and drug targets for diseases.

Potassium Channels, Glucose Metabolism and Glycosylation in Cancer Cells

Potassium channels emerge as one of the crucial groups of proteins that shape the biology of cancer cells. Their involvement in processes like cell growth, migration, or electric signaling, seems obvious. However, the relationship between the function of K+ channels, glucose metabolism, and cancer glycome appears much more intriguing. Among the typical hallmarks of cancer, one can mention the switch to aerobic glycolysis as the most favorable mechanism for glucose metabolism and glycome alterations. This review outlines the interconnections between the expression and activity of potassium channels, carbohydrate metabolism, and altered glycosylation in cancer cells, which have not been broadly discussed in the literature hitherto. Moreover, we propose the potential mediators for the described relations (e.g., enzymes, microRNAs) and the novel promising directions (e.g., glycans-orinented drugs) for further research.

A reduced model of cell metabolism to revisit the glycolysis-OXPHOS relationship in the deregulated tumor microenvironment

Cancer cells metabolism focuses the interest of the cancer research community. Although this process is intensely studied experimentally, there are very few theoretical models that address this issue. One of the main reasons is the extraordinary complexity of the metabolism that involves numerous interdependent regulatory networks which makes the computational recreation of this complexity illusory. In this study we propose a reduced model of the metabolism which focuses on the interrelation of the three main energy metabolites which are oxygen, glucose and lactate in order to better understand the dynamics of the core system of the glycolysis-OXPHOS relationship. So simple as it is, the model highlights the main rules allowing the cell to dynamically adapt its metabolism to its changing environment. It also makes it possible to address this impact at the tissue scale. The simulations carried out in a spheroid show non-trivial spatial heterogeneity of energy metabolism. It further suggests that the metabolic features that are commonly attributed to cancer cells are not necessarily due to an intrinsic abnormality of the cells. They can emerge spontaneously due to the deregulated over-acidic environment.

Tumor acidic environment directs nanoparticle impacts on cancer cells

Despite impressive progress in nanotechnology-based cancer therapy being made by in vitro research, few nanoparticles (NPs) have been translated into clinical trials. The wide gap between in vitro results and nanomedicine's clinical translation might be partly due to acidic microenvironment of cancer cells being ignored in in vitro studies. To check this hypothesis, we studied the biological impacts of two different structures of NPs on cancer cells (MDA-MB 231) at acidic (pH: 6.5) low (pH: 7) and physiological pH (pH: 7.4). We uncovered that a slight change in the pH of the cancer cell microenvironment affects the cellular uptake efficacy and toxicity mechanism of nanographene sheets and SPION@silica nanospheres. Both nanostructures exerted more substantial toxic impacts (e. g. apoptosis, necrosis, membrane disruption, and oxidative stress induction) against cancer cells at physiological pH compared to acidic niche. They also differently slowed or arrested phases of the cell cycle at different pH (S and G2/M at normal pH while G0/G1 at acidic/low pH). More specifically, cancer cells expressed higher levels of interleukins involved in cancer cell resistance at acidic pH than those incubated at physiological pH. This study revealed that a slight change in extracellular pH of cancer cells could strongly affect the therapeutic/toxic impact of nanomaterials and therefore, it should be considered in the future cancer nanomedicine research.

An oncospace for human cancers

Human cancers comprise an heterogeneous array of diseases with different progression patterns and responses to therapy. However, they all develop within a host context that constrains their natural history. Since it occurs across the diversity of organisms, one can conjecture that there is order in the cancer multiverse. Is there a way to capture the broad range of tumor types within a space of the possible? Here we define the oncospace, a coordinate system that integrates the ecological, evolutionary and developmental components of cancer complexity. The spatial position of a tumor results from its departure from the healthy tissue along these three axes, and progression trajectories inform about the components driving malignancy across cancer subtypes. We postulate that the oncospace topology encodes new information regarding tumorigenic pathways, subtype prognosis, and therapeutic opportunities: treatment design could benefit from considering how to nudge tumors toward empty evolutionary dead ends in the oncospace.

Polymer-Based mRNA Delivery Strategies for Advanced Therapies

Messenger RNA (mRNA)-based therapies offer great promise for the treatment of a variety of diseases. In 2020, two FDA approvals of mRNA-based vaccines have elevated mRNA vaccines to global recognition. However, the therapeutic capabilities of mRNA extend far beyond vaccines against infectious diseases. They hold potential for cancer vaccines, protein replacement therapies, gene editing therapies, and immunotherapies. For realizing such advanced therapies, it is crucial to develop effective carrier systems. Recent advances in materials science have led to the development of promising nonviral mRNA delivery systems. In comparison to other carriers like lipid nanoparticles, polymer-based delivery systems often receive less attention, despite their unique ability to carefully tune their chemical features to promote mRNA protection, their favorable pharmacokinetics, and their potential for targeting delivery. In this review, the central features of polymer-based systems for mRNA delivery highlighting the molecular design criteria, stability, and biodistribution are discussed. Finally, the role of targeting ligands for the future of RNA therapies is analyzed.

ER stress-enhanced HMGA2 plays an important role in Cr (VI)-induced glycolysis and inhibited oxidative phosphorylation by targeting the transcription of ATF4

Hexavalent chromium [Cr (VI)] is a proven human carcinogen which is widely used in steel manufacturing and painting. Here, the involvement of high mobility group A2 (HMGA2) in Cr (VI)-mediated glycolysis and oxidative phosphorylation (OXPHOS) was investigated. First, Cr (VI) treatment induced aerobic glycolysis by increasing the expression of GLUT1, HK II, PKM2 and LDHA enzymes, and reduced OXPHOS by decreasing mitochondrial mass, the expression of COX IV and ND1, and increasing Ca²⁺ content in mitochondria in A549 and HELF cells. And overexpression of HMGA2 induced aerobic glycolysis and decreased OXPHOS. Secondly, using endoplasmic reticulum (ER) stress inhibitor, 4-phenylbutyric acid (4-PBA) and knockdown of activating transcription factor 4 (ATF4) gene by siRNA, we demonstrated that ER stress and ATF4 elevation mediated Cr (VI)-induced glycolysis and inhibited OXPHOS. Furthermore, using tunicamycin (Tm), siHMGA2, transfection of HMGA2 and siATF4, we demonstrated that ER stress-enhanced interaction of HMGA2 and ATF4 resulted in Cr (VI)-induced glycolysis and inhibited OXPHOS. Additionally, ChIP assay revealed that HMGA2 protein could directly bind to the promoter sequence of ATF4 gene, which modulated Cr (VI)-induced ATF4 elevation. Finally, in lung tissues of BALB/c mice injected with HMGA2 plasmids, it is verified that HMGA2 involved in regulation of ATF4, glycolysis and OXPHOS in vivo. Combining, our data discovered that ER stress-enhanced the interaction of HMGA2 and ATF4 played an important role in Cr (VI)-mediated glycolysis and OXPHOS. These results imply a root cause for the carcinogenicity of Cr (VI), and could guide development of novel therapeutics for cancers.

Tumor pH Imaging Using Chemical Exchange Saturation Transfer (CEST)-MRI

Magnetic resonance imaging (MRI) is a noninvasive imaging technique that allows for physiological and functional studies of the tumor microenvironment. Within MRI, the emerging field of chemical exchange saturation transfer (CEST) has been largely exploited for assessing a salient feature of all solid tumors, extracellular acidosis. Iopamidol-based tumor pH imaging has been demonstrated to provide accurate and high spatial resolution extracellular tumor pH maps to elucidate tumor aggressiveness and for assessing response to therapy, with a high potential for clinical translation. Here, we describe the overall setup and steps for measuring tumor extracellular pH of tumor models in mice by exploiting MRI-CEST pH imaging with a preclinical MRI scanner following the administration of iopamidol. We address issues of pH calibration curve setup, animal handling, pH-responsive contrast agent injection, acquisition protocol, and image processing for accurate quantification and visualization of tumor acidosis.

Complex I inhibitor of oxidative phosphorylation in advanced solid tumors and acute myeloid leukemia: phase I trials

Although targeting oxidative phosphorylation (OXPHOS) is a rational anticancer strategy, clinical benefit with OXPHOS inhibitors has yet to be achieved. Here we advanced IACS-010759, a highly potent and selective small-molecule complex I inhibitor, into two dose-escalation phase I trials in patients with relapsed/refractory acute myeloid leukemia (NCT02882321, n = 17) and advanced solid tumors (NCT03291938, n = 23). The primary endpoints were safety, tolerability, maximum tolerated dose and recommended phase 2 dose (RP2D) of IACS-010759. The PK, PD, and preliminary antitumor activities of IACS-010759 in patients were also evaluated as secondary endpoints in both clinical trials. IACS-010759 had a narrow therapeutic index with emergent dose-limiting toxicities, including elevated blood lactate and neurotoxicity, which obstructed efforts to maintain target exposure. Consequently no RP2D was established, only modest target inhibition and limited antitumor activity were observed at tolerated doses, and both trials were discontinued. Reverse translational studies in mice demonstrated that IACS-010759 induced behavioral and physiological changes indicative of peripheral neuropathy, which were minimized with the coadministration of a histone deacetylase 6 inhibitor. Additional studies are needed to elucidate the association between OXPHOS inhibition and neurotoxicity, and caution is warranted in the continued development of complex I inhibitors as antitumor agents.

Para-N-Methylpyridinium Pyrenes: Impact of Positive Charge on ds-DNA/RNA and Protein Recognition, Photo-Induced Bioactivity, and Intracellular Localisation

The 2- and 2,7- substituted para-N-methylpyridinium pyrene cations show high-affinity intercalation into ds-DNAs, whereas their non-methylated analogues interacted with ds-DNA/RNA only in the protonated form (at pH 5), but not at physiological conditions (pH 7). The fluorescence from non-methylated analogues was strongly dependent on the protonation of the pyridines; consequently, they act as fluorescence ratiometric probes for simultaneous detection of both ds-DNA and BSA at pH 5, relying on the ratio between intensities at 420 nm (BSA specific) and 520 nm (DNA specific), whereby exclusively ds-DNA sensing could be switched-off by adjustment to pH 7. Only methylated, permanently charged pyrenes show photoinduced cleavage of circular DNA, attributed to pyrene-mediated irradiation-induced production of singlet oxygen. Consequently, the moderate toxicity of these cations against human cell lines is strongly increased upon irradiation. Detailed studies revealed increased total ROS production in cells treated by the compounds studied, accompanied by cell swelling and augmentation of cellular complexity. The most photo-active 2-para-N-methylpyridinium pyrene showed significant localization at mitochondria, its photo-bioactivity likely due to mitochondrial DNA damage. Other derivatives were mostly non-selectively distributed between various cytoplasmic organelles, thus being less photoactive.

Classification of High-Grade Serous Ovarian Cancer Using Tumor Morphologic Characteristics

IMPORTANCE

Despite similar histologic appearance among high-grade serous ovarian cancers (HGSOCs), clinical observations suggest vast differences in gross appearance. There is currently no systematic framework by which to classify HGSOCs according to their gross morphologic characteristics.

OBJECTIVE

To develop and characterize a gross morphologic classification system for HGSOC.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients with suspected advanced-stage ovarian cancer who presented between April 1, 2013, and August 5, 2016, to the University of Texas MD Anderson Cancer Center, a large referral center. Patients underwent laparoscopic assessment of disease burden before treatment and received a histopathologic diagnosis of HGSOC. Researchers assigning morphologic subtype and performing molecular analyses were blinded to clinical outcomes. Data analysis was performed between April 2020 and November 2021.

EXPOSURES

Gross tumor morphologic characteristics.

MAIN OUTCOMES AND MEASURES

Clinical outcomes and multiomic profiles of representative tumor samples of type I or type II morphologic subtypes were compared.

RESULTS

Of 112 women (mean [SD] age 62.7 [9.7] years) included in the study, most patients (84% [94]) exhibited a predominant morphologic subtype and many (63% [71]) had a uniform morphologic subtype at all involved sites. Compared with those with uniform type I morphologic subtype, patients with uniform type II morphologic subtype were more likely to have a favorable Fagotti score (83% [19 of 23] vs 46% [22 of 48]; P = .004) and thus to be triaged to primary tumor reductive surgery. Similarly, patients with uniform type II morphologic subtype also had significantly higher mean (SD) estimated blood loss (639 [559; 95% CI, 391-887] mL vs 415 [527; 95% CI, 253-577] mL; P = .006) and longer mean (SD) operative time (408 [130; 95% CI, 350-466] minutes vs 333 [113; 95% CI, 298-367] minutes; P = .03) during tumor reductive surgery. Type I tumors had enrichment of epithelial-mesenchymal transition (false discovery rate [FDR] q-value, 3.10 × 10-24), hypoxia (FDR q-value, 1.52 × 10-5), and angiogenesis pathways (FDR q-value, 2.11 × 10-2), whereas type II tumors had enrichment of pathways related to MYC signaling (FDR q-value, 2.04 × 10-9) and cell cycle progression (FDR q-value, 1.10 × 10-5) by integrated proteomic and transcriptomic analysis. Abundances of metabolites and lipids also differed between the 2 morphologic subtypes.

CONCLUSIONS AND RELEVANCE

This study identified 2 novel, gross morphologic subtypes of HGSOC, each with unique clinical features and molecular signatures. The findings may have implications for triaging patients to surgery or chemotherapy, identifying outcomes, and developing tailored therapeutic strategies.

Blood glucose levels and the risk of HPV multiple infections in high-grade squamous intraepithelial lesions: A retrospective cross-sectional study of Chinese patients

Besides the controversy of the association of high glycemic index and glycemic load with precancerous cervical lesions, only a few studies have examined the impact of fasting blood glucose levels on human papillomavirus (HPV) multiple infections. In the present study, we appraised the relationship between blood glucose levels and multiple HPV infections in a population of HPV-positive women with cervical high-grade squamous intraepithelial lesions (HSIL). The present study was designed as a cross-sectional correlative analysis. A total of 560 participants with a pathologically confirmed HSIL with HPV infection were included from a hospital in China during January 1, 2018, and December 31, 2019. The target variables and the outcome variables were the glucose levels at the baseline and HPV multiplicity, respectively. The odds ratio and 95% confidence intervals were calculated to estimate the risk of multiple infections via logistic regression analysis. The average age of the 560 participants was 44.63 ± 10.61 years; the nonlinear relationship was detected between the glucose levels and multiplicity of HPV, with an inflection point at 5.4. After adjusting for the full range of variables, the effect sizes and confidence intervals for the left and right sides of the inflection points were found to be 0.379 (0.196-0.732) and 5.083 (1.592-16.229), respectively. In this cross-sectional study, both high and low blood glucose levels increased the risk of multiple HPV infections, demonstrating a U-shaped relationship between the blood glucose levels and multiple HPV infections.

Overcoming the blood–brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood–brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

The cross-talk of autophagy and apoptosis in breast carcinoma: implications for novel therapies?

Breast cancer is still the most common cancer in women worldwide. Resistance to drugs and recurrence of the disease are two leading causes of failure in treatment. For a more efficient treatment of patients, the development of novel therapeutic regimes is needed. Recent studies indicate that modulation of autophagy in concert with apoptosis induction may provide a promising novel strategy in breast cancer treatment. Apoptosis and autophagy are two tightly regulated distinct cellular processes. To maintain tissue homeostasis abnormal cells are disposed largely by means of apoptosis. Autophagy, however, contributes to tissue homeostasis and cell fitness by scavenging of damaged organelles, lipids, proteins, and DNA. Defects in autophagy promote tumorigenesis, whereas upon tumor formation rapidly proliferating cancer cells may rely on autophagy to survive. Given that evasion of apoptosis is one of the characteristic hallmarks of cancer cells, inhibiting autophagy and promoting apoptosis can negatively influence cancer cell survival and increase cell death. Hence, combination of antiautophagic agents with the enhancement of apoptosis may restore apoptosis and provide a therapeutic advantage against breast cancer. In this review, we discuss the cross-talk of autophagy and apoptosis and the diverse facets of autophagy in breast cancer cells leading to novel models for more effective therapeutic strategies.

Proton export upregulates aerobic glycolysis

INTRODUCTION

Aggressive cancers commonly ferment glucose to lactic acid at high rates, even in the presence of oxygen. This is known as aerobic glycolysis, or the "Warburg Effect." It is widely assumed that this is a consequence of the upregulation of glycolytic enzymes. Oncogenic drivers can increase the expression of most proteins in the glycolytic pathway, including the terminal step of exporting H+ equivalents from the cytoplasm. Proton exporters maintain an alkaline cytoplasmic pH, which can enhance all glycolytic enzyme activities, even in the absence of oncogene-related expression changes. Based on this observation, we hypothesized that increased uptake and fermentative metabolism of glucose could be driven by the expulsion of H+ equivalents from the cell.

RESULTS

To test this hypothesis, we stably transfected lowly glycolytic MCF-7, U2-OS, and glycolytic HEK293 cells to express proton-exporting systems: either PMA1 (plasma membrane ATPase 1, a yeast H+-ATPase) or CA-IX (carbonic anhydrase 9). The expression of either exporter in vitro enhanced aerobic glycolysis as measured by glucose consumption, lactate production, and extracellular acidification rate. This resulted in an increased intracellular pH, and metabolomic analyses indicated that this was associated with an increased flux of all glycolytic enzymes upstream of pyruvate kinase. These cells also demonstrated increased migratory and invasive phenotypes in vitro, and these were recapitulated in vivo by more aggressive behavior, whereby the acid-producing cells formed higher-grade tumors with higher rates of metastases. Neutralizing tumor acidity with oral buffers reduced the metastatic burden.

CONCLUSIONS

Therefore, cancer cells which increase export of H+ equivalents subsequently increase intracellular alkalization, even without oncogenic driver mutations, and this is sufficient to alter cancer metabolism towards an upregulation of aerobic glycolysis, a Warburg phenotype. Overall, we have shown that the traditional understanding of cancer cells favoring glycolysis and the subsequent extracellular acidification is not always linear. Cells which can, independent of metabolism, acidify through proton exporter activity can sufficiently drive their metabolism towards glycolysis providing an important fitness advantage for survival.

Introduction of mutant TP53 related genes in metabolic pathways and evaluation their correlation with immune cells, drug resistance and sensitivity

BACKGROUND

Although the relationship between TP53 mutation, TP53 metabolism pathways, and tumorigenesis has been investigated, pan-cancer analysis of TP53 mutations and related metabolism pathways is not completely available in common types of human cancers. Thus, this study was going to represent TP53 mutant-related metabolism genes and pathways in a pan-cancer study and investigate the relationship between selected genes and drug resistance.

METHODS

The DNA-seq data, RNA-seq data, and clinical information of 12 types of cancer were downloaded from the cancer genome atlas (TCGA) database. GSE70479 data were obtained from GEO database for validation of our TCGA data. To evaluate the survival rate of patients, GEPIA2 was applied. The CCLE and GDSC database were used to investigate drug resistance and sensitivity.

RESULTS

Our findings indicated that TTN, MUC16, and TP53 were present in 12 types of cancer with high level of mutation frequency which abundance of TP53 mutations was higher. Mutant TP53-related (mTP53) pathways and genes including PKM, SLC16A3, HK2, PFKP, PHGDH, and CTSC were obtained from enrichment analysis and interestingly, top pathways were associated with metabolism including glycolysis and mTORC1 pathway. Our results showed the expression of some candidate genes correlated with immune markers, prognosis, and drug resistance.

CONCLUSIONS

Top mutant genes for 12 cancers were highlighted while TP53 was selected as top mutant gene, and metabolic genes associated with the TP53 mutation were identified that some of which are important in poor prognosis. In doing so, mutations in TP53 could run some metabolic pathways and drug resistance and sensitivity.

Ring finger protein 180 suppresses cell proliferation and energy metabolism of non-small cell lung cancer through downregulating C-myc

Background

Non-small cell lung cancer (NSCLC) causes numerous deaths worldwide. however, biomarkers for NSCLC prognosis are scarce for its heterogeneity. Proteins containing the RING finger domain RING finger protein 180 (RNF180) is a key mediator for ubiquitination, which controls cell cycle and regulates progression in certain human tumors. However, the detailed function of RNF180 in NSCLC remains unclear. In the present study, we aimed to investigate the role of RNF180 and its molecule network in NSCLC.

Methods

Quantitative real-time polymerase chain reaction and immunohistochemical staining were used to analyze RNF180 levels. RNA interference and lentiviral-mediated vector transfections were performed to silence and overexpress RNF180 in NSCLC cells. Furthermore, Cell Counting Kit-8 was used for assessing biological function of RNF180 in cell proliferation and a xenograft model for examining its function in vivo. The activity of glycolysis was determined by examining the level of the extracellular acidification rate (ECAR).

Results

RNF180 expression decreased in NSCLC tissues, and its expression was positively correlated with the survival rate of patients with NSCLC. Moreover, RNF180 overexpression suppressed the proliferation and glycolytic activities in NSCLC cells and restricted its tumorigenicity in vivo. Furthermore, RNF180 silencing promoted the proliferation and glycolysis metabolism of NSCLC cells, whereas C-myc inhibitor disrupted these effects. The underlying anti-oncogene of RNF180 involved in C-myc downregulation via ubiquitin-dependent degradation.

Conclusions

Together, these results firstly indicated the anti-tumor properties of RNF180 and its correlation with NSCLC progression, thereby endorsing the potential role of RNF180 as an efficient prognostic biomarker for tumor recurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02599-x.

The risk of increasing tumor malignancy after PET diagnosis

This manuscript reviews evidences underlying the estimation of risk of malignancy enhancement of advanced aggressive cancers as a result of the gamma radiation emitted by tracers used in PET diagnostics. We conclude that among many cancers, such a phenomenon likely occurs, particularly in tumor cells with an aggressive biology in the advanced stages of their development, e.g. prostate cancer, melanoma and colorectal cancer. Moreover, we surmise based on gathered evidence that fluorine -18 (18F) labeled pharmaceuticals (18F-deoxyglucose and 18F-choline), commonly used in positron emission tomography (PET) can lead to malignancy enhancement of diagnosed cancer, manifesting as accelerated infiltration of the neighboring tissue, accelerated metastasis and/or radio- and chemotherapy resistance. In this review, some suggestions on future studies verifying this concept are also proposed. If our concerns are justified, it might be appropriate in the future to consider this assumption at the stage of deciding whether to undertake PET monitoring in some patients with advanced aggressive cancer.

Lipogenesis mediated by OGR1 regulates metabolic adaptation to acid stress in cancer cells via autophagy

Malignant tumors exhibit altered metabolism resulting in a highly acidic extracellular microenvironment. Here, we show that cytoplasmic lipid droplet (LD) accumulation, indicative of a lipogenic phenotype, is a cellular adaption to extracellular acidity. LD marker PLIN2 is strongly associated with poor overall survival in breast cancer patients. Acid-induced LD accumulation is triggered by activation of the acid-sensing G-protein-coupled receptor (GPCR) OGR1, which is expressed highly in breast tumors. OGR1 depletion inhibits acid-induced lipid accumulation, while activation by a synthetic agonist triggers LD formation. Inhibition of OGR1 downstream signaling abrogates the lipogenic phenotype, which can be rescued with OGR1 ectopic expression. OGR1-depleted cells show growth inhibition under acidic growth conditions in vitro and tumor formation in vivo. Isotope tracing shows that the source of lipid precursors is primarily autophagy-derived ketogenic amino acids. OGR1-depleted cells are defective in endoplasmic reticulum stress response and autophagy and hence fail to accumulate LDs affecting survival under acidic stress.

Long noncoding RNA MRPL23-AS1 suppresses anoikis in salivary adenoid cystic carcinoma in vitro

Distant lung metastasis is the main factor that affects the survival rate of patients with salivary adenoid cystic carcinoma (SACC). Anoikis resistance is a feature of tumor cells that easily metastasize. The long non-coding RNA (lncRNA) MRPL23 antisense RNA 1 (MPRL23-AS1) is related to lung metastasis in SACC, but its role in anoikis resistance is unknown.After altering MPRL23-AS1 expression in SACC cells, anoikis resistance was detected by calcein AM/PI staining and annexin V/PI flow cytometry. The apoptosis marker activated caspase-3 and the bcl-2/bax ratio were detected by Western blotting. The relationship between MPRL23-AS1 and the promoter of the potential downstream target gene p19INK4D was identified by chromatin immunoprecipitation (ChIP)-PCR assay. p19INK4D expression in patient tissues was determined using qRT-PCR and immunohistochemistry.The functional experiments showed that MPRL23-AS1 could promote anoikis resistance in vitro. MRPL23-AS1 recruited the EZH2 to the promoter region of p19INK4D, inhibited p19INK4D expression, and promoted tumor cell anoikis resistance. p19INK4D overexpression did not affect anoikis in attached cells; however, it attenuated the anoikis resistance effect of MPRL23-AS1 in suspension cells. p19INK4D expression was significantly lower in SACC tissues than in normal tissues.The novel MRPL23-AS1/p19INK4D axis may be a potential SACC biomarker or therapeutic target.

Travelling-wave analysis of a model of tumour invasion with degenerate, cross-dependent diffusion

In this paper, we carry out a travelling-wave analysis of a model of tumour invasion with degenerate, cross-dependent diffusion. We consider two types of invasive fronts of tumour tissue into extracellular matrix (ECM), which represents healthy tissue. These types differ according to whether the density of ECM far ahead of the wave front is maximal or not. In the former case, we use a shooting argument to prove that there exists a unique travelling-wave solution for any positive propagation speed. In the latter case, we further develop this argument to prove that there exists a unique travelling-wave solution for any propagation speed greater than or equal to a strictly positive minimal wave speed. Using a combination of analytical and numerical results, we conjecture that the minimal wave speed depends monotonically on the degradation rate of ECM by tumour cells and the ECM density far ahead of the front.

Defining the landscape of metabolic dysregulations in cancer metastasis

Metastasis is the primary cause of cancer related deaths due to the limited number of efficient druggable targets. Signatures of dysregulated cancer metabolism could serve as a roadmap for the determination of new treatment strategies. However, the metabolic signatures of metastatic cells remain vastly elusive. Our aim was to determine metabolic dysregulations associated with high metastatic potential in breast cancer cell lines. We have selected 5 triple negative breast cancer (TNBC) cell lines including three with high metastatic potential (HMP) (MDA-MB-231, MDA-MB-436, MDA-MB-468) and two with low metastatic potential (LMP) (BT549, HCC1143). The normal epithelial breast cell line (hTERT-HME1) was also investigated. The untargeted metabolic profiling of cells and growth media was conducted and total of 479 metabolites were quantified. First we characterized metabolic features differentiating TNBC cell lines from normal cells as well as identified cell line specific metabolic fingerprints. Next, we determined 92 metabolites in cells and 22 in growth medium that display significant differences between LMP and HMP. The HMP cell lines had elevated level of molecules involved in glycolysis, TCA cycle and lipid metabolism. We identified metabolic advantages of cell lines with HMP beyond enhanced glycolysis by pinpointing the role of branched chain amino acids (BCAA) catabolism as well as molecules supporting coagulation and platelet activation as important contributors to the metastatic cascade. The landscape of metabolic dysregulations, characterized in our study, could serve as a roadmap for the identification of treatment strategies targeting cancer cells with enhanced metastatic potential.

Targeting the Interplay between Cancer Metabolic Reprogramming and Cell Death Pathways as a Viable Therapeutic Path

In cancer cells, metabolic adaptations are often observed in terms of nutrient absorption, biosynthesis of macromolecules, and production of energy necessary to meet the needs of the tumor cell such as uncontrolled proliferation, dissemination, and acquisition of resistance to death processes induced by both unfavorable environmental conditions and therapeutic drugs. Many oncogenes and tumor suppressor genes have a significant effect on cellular metabolism, as there is a close relationship between the pathways activated by these genes and the various metabolic options. The metabolic adaptations observed in cancer cells not only promote their proliferation and invasion, but also their survival by inducing intrinsic and acquired resistance to various anticancer agents and to various forms of cell death, such as apoptosis, necroptosis, autophagy, and ferroptosis. In this review we analyze the main metabolic differences between cancer and non-cancer cells and how these can affect the various cell death pathways, effectively determining the susceptibility of cancer cells to therapy-induced death. Targeting the metabolic peculiarities of cancer could represent in the near future an innovative therapeutic strategy for the treatment of those tumors whose metabolic characteristics are known.

Silencing of Pyruvate Kinase M2 via a Metal-Organic Framework Based Theranostic Gene Nanomedicine for Triple-Negative Breast Cancer Therapy

Triple-negative breast cancer (TNBC) is typically associated with poor prognosis due to its only partial response to chemotherapy and lack of clinically established targeted therapies coupled with an aggressive disease course. Aerobic glycolysis is a hallmark of reprogrammed metabolic activity in cancer cells, which can be repressed by small-interfering RNA (siRNA). However, the lack of effective carriers to deliver vulnerable siRNA restricts the clinical potentials of glycolysis-based gene therapy for TNBC. Herein, we develop a tumor-targeted, biomimetic manganese dioxide (MnO₂)-shrouded metal-organic framework (MOF) based nanomedicine to deliver siRNA against pyruvate kinase muscle isozyme M2 (siPKM2), wherein PKM2 is a rate-limiting enzyme in glycolysis, to inhibit the reprogrammed glycolysis of TNBC. This MOF-based genetic nanomedicine shows excellent monodispersity and stability and protects siPKM2 against degradation by nucleases. The nanomedicine not only substantially blocks the glycolytic pathway but also improves intracellular hypoxia in TNBC cells, with a resultant O₂-enhanced anticancer effect. In the mice orthotopic TNBC model, the nanomedicine shows a remarkable therapeutic effect. Meanwhile, the Mn²⁺ ions released from acid microenvironment-responsive MnO₂ enable in vivo monitoring of the therapeutic process with magnetic resonance imaging (MRI). Our study shows great promise with this MRI-visible MOF-based nanomedicine for treating TNBC by inhibition of glycolysis via the RNA interference.

Prognostic value of metabolic signature on 18F-FDG uptake in breast cancer patients after radiotherapy

Radiotherapy (RT) is a major modality of postoperative treatment in breast cancer. The maximal standardized value (SUVmax) is ¹⁸FDG-PET/CT derived parameter that reported to be a valuable prognostic factor in cancer patients. Herein, we aimed to identify a prognostic gene signature associated with glucose uptake for breast cancer patients after RT by leveraging the mRNA expression profiling on public datasets. The glucose uptake signature was constructed using the single sample gene set enrichment analysis (ssGSEA) algorithm and evaluated in GSE21217 where SUVmax value was measured by PET-CT directly. The prognostic value was validated in three post-RT breast cancer cohorts (GSE103744, NKI, and FUSCC databases). The patients were stratified into glucose uptake signature score-high and low groups. Patients with a higher score had worse survival than those with a lower score. Mechanistically, the glucose uptake signature was calculated in each cell type of a single-cell RNA-seq database from five breast cancer patients. Glucose uptake signature score was significantly elevated in the malignant epithelial cells compared with normal ones. The immunosuppression markers including PDCD1, TIGIT, LAG3, and HAVCR2 were significantly upregulated in the T cells bearing a high glucose uptake signature score. Collectively, our results demonstrated the potential prognostic value of a glucose uptake signature in the post-RT breast cancer patients.

A Tale of Two Bioconjugations: pH Controlled Divergent Reactivity of Protein α-oxo-Aldehydes in Competing α-oxo-Mannich and Catalyst-Free Aldol Ligations

Site-selective chemical methods for protein bioconjugation have revolutionized the fields of cell and chemical biology through the development of novel protein/enzyme probes bearing fluorescent, spectroscopic, or even toxic cargos. Herein, we report two new methods for the bioconjugation of α-oxo aldehyde handles within proteins using small molecule aniline and/or phenol probes. The "α-oxo-Mannich" and "catalyst-free aldol" ligations both compete for the electrophilic α-oxo aldehyde, which displays pH divergent reactivity proceeding through the "Mannich" pathway at acidic pH to afford bifunctionalized bioconjugates, and the "catalyst-free aldol" pathway at neutral pH to afford monofunctionalized bioconjugates. We explore the substrate scope and utility of both of these bioconjugations in the construction of neoglycoproteins, in the process formulating a mechanistic rationale for how both pathways intersect with each other at different reaction pH's.

Platelet isoform of phosphofructokinase accelerates malignant features in breast cancer

The platelet isoform of phosphofructokinase (PFKP) is one of the key enzymes in the glycolytic pathway. PFKP is highly expressed in several cancers, and it has been reported to be involved in the progression of cancer cells. However, its oncological role in breast cancer (BC) remains unclear. The present study aimed to evaluate the function of PFKP in BC cells and its expression level in patients with BC. Firstly, the mRNA and protein expression of PFKP was evaluated in BC and non‑cancerous mammary cell lines. Polymerase chain reaction (PCR) array analysis was conducted to evaluate the correlation between PFKP and 84 cancer‑related genes. Then, PFKP knockdown was conducted using small interfering RNA, and cell proliferation, invasiveness and migration were analyzed. Furthermore, the association between PFKP mRNA expression and clinicopathological factors was investigated in 167 patients with BC. PFKP was highly expressed in estrogen receptor‑negative and human epidermal growth factor receptor 2‑negative BC cell lines. PCR array analysis demonstrated that the expression level of PFKP was significantly correlated with that of transforming growth factor‑β1 and MYC proto‑oncogene. PFKP knockdown significantly decreased the proliferation and invasiveness of MCF7, SK‑BR‑3, and MDA‑MB‑231 cells. Furthermore, cell migration was inhibited in SK‑BR‑3 and MDA‑MB‑231 cells. In the clinical specimens, patients with T2/T3/T4, lymph node metastasis, or stage II/III/IV exhibited higher expression of PFKP mRNA than patients with less severe disease. In conclusion, the present findings indicated that PFKP is involved in promoting tumor‑progressive oncological roles in BC cells across different subtypes and is considered a possible novel therapeutic target for BC.