POU1F1 transcription factor induces metabolic reprogramming and breast cancer progression via LDHA regulation

The early-stage clinical course of anti-pituitary-specific transcription factor-1 hypophysitis diagnosed post-immune checkpoint inhibitor treatment: A case with review of literature

Anti-pituitary-specific transcription factor-1 (PIT-1) hypophysitis, a paraneoplastic syndrome resulting from an autoimmune response against PIT-1, typically manifests with undetectable levels of growth hormone (GH) and prolactin (PRL), and significantly low levels of serum thyroid-stimulating hormone (TSH) at diagnosis. These hormonal levels are highly specific to this disease and serve as key diagnostic indicators. Herein, we present a detailed clinical course of a 69-year-old male with a history of gastric cancer and lymph node metastases who developed anti-PIT-1 hypophysitis after the initiation of immune checkpoint inhibitor (ICI) therapy, specifically nivolumab, oxaliplatin, and capecitabine. The patient was referred to our department owing to decreased TSH, free triiodothyronine (T3), and free thyroxine (T4) levels after two doses of nivolumab. Initially suspected as central hypothyroidism due to ICI-related hypophysitis, further assessment confirmed the diagnosis of anti-PIT-1 hypophysitis. Notably, GH, PRL, and TSH levels markedly declined, leading to complete deficiencies 2 months after the first nivolumab dose-a pattern consistent with that of previous cases of anti-PIT-1 hypophysitis. Therefore, this report not only presents an atypical subset of ICI-related hypophysitis but also delineates the process of hormone impairment leading to complete deficiencies in anti-PIT-1 hypophysitis. This case highlights the importance of vigilant monitoring for endocrine issues in patients undergoing ICI therapy, given the escalating incidence of immune-related adverse events associated with the extensive use of ICI therapy for various cancers.

Metastatic outgrowth via the two-way interplay of autophagy and metabolism

Metastasis represents one of the most dangerous issue of cancer progression, characterized by intricate interactions between invading tumor cells, various proteins, and other cells on the way towards target sites. Tumor cells, while undergoing metastasis, engage in dynamic dialogues with stromal cells and undertake epithelial-mesenchymal transition (EMT) phenoconversion. To ensure survival, tumor cells employ several strategies such as restructuring their metabolic needs to adapt to the alterations of the microenvironmental resources via different mechanisms including macroautophagy (autophagy) and to circumvent anoikis-a form of cell death induced upon detachment from the extracellular matrix (ECM). This review focuses on the puzzling connections of autophagy and energetic metabolism within the context of cancer metastasis.

Transcription factors in fibroblast plasticity and CAF heterogeneity

In recent years, research focused on the multifaceted landscape and functions of cancer-associated fibroblasts (CAFs) aimed to reveal their heterogeneity and identify commonalities across diverse tumors for more effective therapeutic targeting of pro-tumoral stromal microenvironment. However, a unified functional categorization of CAF subsets remains elusive, posing challenges for the development of targeted CAF therapies in clinical settings.The CAF phenotype arises from a complex interplay of signals within the tumor microenvironment, where transcription factors serve as central mediators of various cellular pathways. Recent advances in single-cell RNA sequencing technology have emphasized the role of transcription factors in the conversion of normal fibroblasts to distinct CAF subtypes across various cancer types.This review provides a comprehensive overview of the specific roles of transcription factor networks in shaping CAF heterogeneity, plasticity, and functionality. Beginning with their influence on fibroblast homeostasis and reprogramming during wound healing and fibrosis, it delves into the emerging insights into transcription factor regulatory networks. Understanding these mechanisms not only enables a more precise characterization of CAF subsets but also sheds light on the early regulatory processes governing CAF heterogeneity and functionality. Ultimately, this knowledge may unveil novel therapeutic targets for cancer treatment, addressing the existing challenges of stromal-targeted therapies.

Combined inhibition of pyruvate dehydrogenase kinase 1 and lactate dehydrogenase a induces metabolic and signaling reprogramming and enhances lung adenocarcinoma cell killing

Lung adenocarcinoma (LUAD) is one of the most prevalent and aggressive types of lung cancer. Metabolic reprogramming plays a critical role in the development and progression of LUAD. Pyruvate dehydrogenase kinase 1 (PDK1) and lactate dehydrogenase A (LDHA) are two key enzymes involved in glucose metabolism, whilst their aberrant expressions are often associated with tumorigenesis. Herein, we investigated the anticancer effects of combined inhibition of PDK1 and LDHA in LUAD in vitro and in vivo and its underlying mechanisms of action. The combination of a PDK1 inhibitor, 64, and a LDHA inhibitor, NHI-Glc-2, led to a synergistic growth inhibition in 3 different LUAD cell lines and more than additively suppressed tumor growth in the LUAD xenograft H1975 model. This combination also inhibited cellular migration and colony formation, while it induced a metabolic shift from glycolysis to oxidative phosphorylation (OXPHOS) resulting in mitochondrial depolarization and apoptosis in LUAD cells. These effects were related to modulation of multiple cell signaling pathways, including AMPK, RAS/ERK, and AKT/mTOR. Our findings demonstrate that simultaneous inhibition of multiple glycolytic enzymes (PDK1 and LDHA) is a promising novel therapeutic approach for LUAD.

Metastases and treatment-resistant lineages in patient-derived cancer cells of colorectal cancer

Circulating tumor cells (CTCs) play an important role in metastasis and recurrence. However, which cells comprise the complex tumor lineages in recurrence and are key in metastasis are unknown in colorectal cancer (CRC). CRC with high expression of POU5F1 has a poor prognosis with a high incidence of liver metastatic recurrence. We aim to reveal the key cells promoting metastasis and identify treatment-resistant lineages with established EGFP-expressing organoids in two-dimensional culture (2DOs) under the POU5F1 promotor. POU5F1-expressing cells are highly present in relapsed clinical patients' blood as CTCs. Sorted POU5F1-expressing cells from 2DOs have cancer stem cell abilities and abundantly form liver metastases in vivo. Single-cell RNA sequencing of 2DOs identifies heterogeneous populations derived from POU5F1-expressing cells and the Wnt signaling pathway is enriched in POU5F1-expressing cells. Characteristic high expression of CTLA4 is observed in POU5F1-expressing cells and immunocytochemistry confirms the co-expression of POU5F1 and CTLA4. Demethylation in some CpG islands at the transcriptional start sites of POU5F1 and CTLA4 is observed. The Wnt/β-catenin pathway inhibitor, XAV939, prevents the adhesion and survival of POU5F1-expressing cells in vitro. Early administration of XAV939 also completely inhibits liver metastasis induced by POU5F1-positive cells.

Further Studies on the Highly Active Des-C-Ring and Aromatic-D-Ring Analogues of 1α,25-Dihydroxyvitamin D3 (Calcitriol): Refinement of the Side Chain

Current efforts in the vitamin D field are directed toward the development of highly antiproliferative yet noncalcemic analogues of the natural hormone 1α,25-dihydroxyvitamin D3 (1,25D3). We have recently reported the design, synthesis, biological evaluation, and crystal structures of a series of novel analogues that both lack the steroidal C-ring and have an m-phenylene ring replacing the steroidal cyclopentane D-ring. We have now investigated the potentiating effects of incorporating selected modifications (hexafluorination and/or an internal triple bond) within the steroidal side chain in our series. An alternative synthetic strategy (Wittig-Horner approach instead of our previously used Pd-catalyzed tandem cyclization/cross-coupling) for the construction of the vitamin D triene system was found convenient for the target compounds 2, 3a, 3b, and 3c of this report. These modifications enhance vitamin D nuclear receptor (VDR) interactions and consequently VDR-associated biological properties compared to parental PG-136 compound while maintaining normal calcium levels.

Role of POU1F1 promoting the properties of stemness of gastric carcinoma through ENO1-mediated glycolysis reprogramming

Cancer stem cells (CSCs), a rare subset of tumor cells, have been recognized as promotive role on tumor initiation and propagation. Among, aerobic glycolysis, widely clarified in multiple tumor cells, is the key for maintaining cancer stemness. Regrettably, it is largely unknown about the connection of cellular metabolic reprogramming and stemness in gastric carcinoma (GC). Two GC parental cells lines PAMC-82 and SNU-16 and their spheroids were obtained to determine the expression status of POU1F1 using quantitative real-time PCR (qRT-PCR) and western blotting analysis, respectively. Gain or loss-of-function assay was employed to assess its biological effects. Sphere formation and transwell assays were performed to evaluate the stem cell-like traits, including self-renewal capacity, migration and invasion. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays were conducted for determining the binding relationship of POU1F1 on ENO1 promoter region. Herein, aberrantly upregulated POU1F1 was observed in spheroids, compared with the parental PAMC-82 and SNU-16 cells, which promoted stem cell-like traits, as representing increasing sphere formation, enhanced cell migration and invasion. Additionally, POU1F1 expression was positively with glycolytic signaling, as displaying increasing glucose consumption, lactic acid production, and extracellular acid ratio (ECAR). Furthermore, POU1F1 was identified to be a transcriptional activator of ENO1, of which overexpression remarkably abolished POU1F1 knockdown-mediated blocking effects. Taken together, we draw a conclusion that POU1F1 facilitated the stem cell-like properties of GC cells through transcriptionally augmenting ENO1 to enhance glycolysis.

Lactate metabolic pathway regulates tumor cell metastasis and its use as a new therapeutic target

Abnormal energy metabolism is one of the ten hallmarks of tumors, and tumor cell metabolism provides energy and a suitable microenvironment for tumorigenesis and metastasis. Tumor cells can consume large amounts of glucose and produce large amounts of lactate through glycolysis even in the presence of oxygen, a process called aerobic glycolysis, also known as the Warburg effect. Lactate is the end product of the aerobic glycolysis. Lactate dehydrogenase A (LDHA), which is highly expressed in cancer cells, promotes lactate production and transports lactate to the tumor microenvironment and is taken up by surrounding stromal cells under the action of monocarboxylate transporter 1/4 (MCT1/4), which in turn influences the immune response and enhances the invasion and metastasis of cancer cells. Therapeutic strategies targeting lactate metabolism have been intensively investigated, focusing on its metastasis-promoting properties and various target inhibitors; AZD3965, an MCT1 inhibitor, has entered phase I clinical trials, and the LDHA inhibitor N-hydroxyindole (NHI) has shown cancer therapeutic activity in pre-clinical studies. Interventions targeting lactate metabolism are emerging as a promising option for cancer therapy, with chemotherapy or radiotherapy combined with lactate-metabolism-targeted drugs adding to the effectiveness of cancer treatment. Based on current research, this article outlines the role of lactate metabolism in tumor metastasis and the potential value of inhibitors targeting lactate metabolism in cancer therapy.

Cancer-associated fibroblasts: from basic science to anticancer therapy

Cancer-associated fibroblasts (CAFs), as a central component of the tumor microenvironment in primary and metastatic tumors, profoundly influence the behavior of cancer cells and are involved in cancer progression through extensive interactions with cancer cells and other stromal cells. Furthermore, the innate versatility and plasticity of CAFs allow their education by cancer cells, resulting in dynamic alterations in stromal fibroblast populations in a context-dependent manner, which highlights the importance of precise assessment of CAF phenotypical and functional heterogeneity. In this review, we summarize the proposed origins and heterogeneity of CAFs as well as the molecular mechanisms regulating the diversity of CAF subpopulations. We also discuss current strategies to selectively target tumor-promoting CAFs, providing insights and perspectives for future research and clinical studies involving stromal targeting.

Tumor immune microenvironment in pituitary neuroendocrine tumors (PitNETs): increased M2 macrophage infiltration and PD-L1 expression in PIT1-lineage subset

PURPOSE

Tumor immune microenvironment in pituitary neuroendocrine tumors (PitNETs) and application of current immunotherapy for refractory PitNETs remains debated. We aim to evaluate the immune landscape in different lineages of PitNETs and determine the potential role of pituitary transcription factors in reshaping the tumor immune microenvironment (TIME), thus promoting the application of current immunotherapy for aggressive and metastatic PitNETs.

METHODS

Immunocyte infiltration and expression patterns of immune checkpoint molecules in different lineages of PitNETs were estimated via in silico analysis and validated using an IHC validation cohort. The correlation between varying immune components with clinicopathological features was assessed in PIT1-lineage PitNETs.

RESULTS

Transcriptome profiles from 210 PitNETs/ 8 normal pituitaries (NPs) and immunohistochemical validations of 77 PitNETs/6 NPs revealed a significant increase in M2-macrophage infiltration in PIT1-lineage PitNETs, compared with the TPIT-lineage, SF1-lineage subsets and NPs. While CD68 + macrophage, CD4 + T cells, and CD8 + T cells were not different among them. Increased M2-macrophage infiltration was associated with tumor volume (p < 0.0001, r = 0.57) in PIT1-lineage PitNETs. Meanwhile, differentially expressed immune checkpoint molecules (PD-L1, PD1, and CTLA-4) were screened and validated in IHC cohorts. The results showed that PD-L1 was highly expressed in PIT1-lineage subsets, and PD-L1 overexpression showed a positive correlation with tumor volume (p = 0.04, r = 0.29) and cavernous sinus invasion (p < 0.0001) in PIT1-lineage PitNETs.

CONCLUSION

PIT1-lineage PitNETs exhibit a distinct immune profile with enrichment of M2 macrophage infiltration and PD-L1 expression, which may contribute to its clinical aggressiveness. Application of current immune checkpoint inhibitors and M2-targeted immunotherapy might be more beneficial to treat aggressive and metastatic PIT-lineage PitNETs.

The hsa_circ_0000276-ceRNA regulatory network and immune infiltration in cervical cancer

BACKGROUND

Our previous studies have confirmed that miR-154-5p can regulate pRb expression, and thus, play a tumor suppressor role in HPV16 E7-induced cervical cancer. However, its upstream molecules have not been elucidated in the progression of cervical cancer. This study aimed to explore the role of the miR-154-5p upstream molecule, hsa_circ_0000276 in cervical cancer development and its possible mechanisms of action.

METHODS

We detected differences in whole transcriptome expression profiles of cervical squamous carcinoma and tissues adjacent to cervical cancer tissues from patients using microarray technology to predict circular RNAs (circRNAs) with binding sites to miR-154-5p. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression of hsa_circ_0000276 (which had the strongest binding capacity to miR-154 and was selected as the target molecule) in cervical cancer tissues, followed by in vitro functional assays. Downstream microRNAs (miRNAs) and mRNAs of hsa_circ_0000276 were identified using transcriptome microarray data and databases, while the protein-protein interaction networks were obtained using STRING. A competing endogenous RNA (ceRNA) network centered on hsa_circ_0000276 was constructed using Cytoscape and GO and KEGG databases. Abnormal expression and prognosis of critical downstream molecules were analyzed using gene databases and molecular experiments. qRT-PCR and western blot analysis was performed to verify the expression of candidate genes.

RESULTS

We identified 4,001 differentially expressed circRNAs between HPV16-positive cervical squamous carcinoma and benign cervical tissues and 760 circRNAs targeting miR-154-5p, including hsa_circ_0000276. hsa_circ_0000276 and miR-154-5p directly bound, and hsa_circ_0000276 was upregulated, in cervical precancerous lesions and cervical cancer tissues and cells. Silencing hsa_circ_0000276 inhibited G1/S transition and cell proliferation and promoted apoptosis in SiHa and CaSki cells. Bioinformatics analysis showed that the hsa_circ_0000276 ceRNA network included 17 miRNAs and seven mRNAs, and downstream molecules of hsa_circ_0000276 were upregulated in cervical cancer tissues. These downstream molecules were associated with a poor prognosis and affected cervical cancer-associated immune infiltration. Of these, expression of CD47, LDHA, PDIA3, and SLC16A1 was downregulated in sh_hsa_circ_0000276 cells.

CONCLUSIONS

Our findings show that hsa_circ_0000276 exerts cancer-promoting effects in cervical cancer and is an underlying biomarker for cervical squamous cell carcinoma.

Histopathogenesis of bone- and soft-tissue tumor spectrum with USP6 gene rearrangement: multiple partners involved in the tissue repair process

Primary aneurysmal bone cyst, nodular fasciitis, myositis ossificans and related lesions as well as fibroma of tendon sheath are benign tumors that share common histological features and a chromosomal rearrangement involving the ubiquitin-specific peptidase 6 (USP6) gene. The tumorigenesis of this tumor spectrum has become complex with the identification of an increasing number of new partners involved in USP6 rearrangements. Because traumatic involvement has long been mentioned in the histogenesis of most lesions in the USP6 spectrum and they morphologically resemble granulation tissue or callus, we attempted to shed light on the function and role USP6 partners play in tissue remodelling and the repair process and, to a lesser extent, bone metabolism.

Glycolysis-related lncRNA TMEM105 upregulates LDHA to facilitate breast cancer liver metastasis via sponging miR-1208

Increased glycolysis is one of the key metabolic hallmarks of cancer cells. However, the roles of lncRNAs in energy metabolism and cancer metastasis remain unclear. Here, the expression of TMEM105 associated with glycolysis was dramatically elevated from normal to breast cancer to breast cancer liver metastasis tissues, and the survival analysis revealed that high TMEM105 expression was related to poor survival, especially in patients with liver metastasis. Moreover, TMEM105 facilitated the glycolysis of breast cancer cells and induced cell invasion and breast cancer liver metastasis (BCLM). Mechanistically, TMEM105 regulated LDHA expression by sponging miR-1208, which further promoted cell glycolysis and BCLM. Importantly, glycolytic production of lactate enhanced TMEM105 expression in breast cancer cells by activating the SHH-MAZ signaling pathway. These findings suggested that the lactate-responsive TMEM105 acted as a miRNA sponge, inducing BCLM via a glycolysis-mediated positive feedback loop, which might be a rational target for the treatment of BCLM patients.

LDHA as a regulator of T cell fate and its mechanisms in disease

T cells are the main force of anti-infection and antitumor and are also involved in autoimmune diseases. During the development of these diseases, T cells need to rapidly produce large amounts of energy to satisfy their activation, proliferation, and differentiation. In this review, we introduced lactate dehydrogenase A(LDHA), predominantly involved in glycolysis, which provides energy for T cells and plays a dual role in disease by mediating lactate production, non-classical enzyme activity, and oxidative stress. Mechanistically, the signaling molecule can interact with the LDHA promoter or regulate LDHA activity through post-translational modifications. These latest findings suggest that modulation of LDHA may have considerable therapeutic effects in diseases where T-cell activation is an important pathogenesis.

Fibrous Matrix Architecture-Dependent Activation of Fibroblasts with a Cancer-Associated Fibroblast-like Phenotype

Cancer-associated fibroblasts (CAFs) are one of the most prevalent cell types within the tumor microenvironment (TME). While several physicochemical cues from the TME, including growth factors, cytokines, and ECM specificity, have been identified as essential factors for CAF activation, the precise mechanism of how the ECM architecture regulates CAF initiation remains elusive. Using a gelatin-based electrospun fiber mesh, we examined the effect of matrix fiber density on CAF activation induced by MCF-7 conditioned media (CM). A less dense (3D) gelatin mesh matrix facilitated better activation of dermal fibroblasts into a CAF-like phenotype in the CM than a highly dense (3D) gelatin mesh matrix. In addition, it was discovered that CAF activation on the less dense (LD) matrix is dependent on the cell size-related AKT/mTOR signaling cascade, accompanied by an increase in intracellular tension within the well-spread fibroblasts.

Metabolic enzyme LDHA activates Rac1 GTPase as a noncanonical mechanism to promote cancer

The glycolytic enzyme lactate dehydrogenase A (LDHA) is frequently overexpressed in cancer, which promotes glycolysis and cancer. The oncogenic effect of LDHA has been attributed to its glycolytic enzyme activity. Here we report an unexpected noncanonical oncogenic mechanism of LDHA; LDHA activates small GTPase Rac1 to promote cancer independently of its glycolytic enzyme activity. Mechanistically, LDHA interacts with the active form of Rac1, Rac1-GTP, to inhibit Rac1-GTP interaction with its negative regulator, GTPase-activating proteins, leading to Rac1 activation in cancer cells and mouse tissues. In clinical breast cancer specimens, LDHA overexpression is associated with higher Rac1 activity. Rac1 inhibition suppresses the oncogenic effect of LDHA. Combination inhibition of LDHA enzyme activity and Rac1 activity by small-molecule inhibitors displays a synergistic inhibitory effect on breast cancers with LDHA overexpression. These results reveal a critical oncogenic mechanism of LDHA and suggest a promising therapeutic strategy for breast cancers with LDHA overexpression.

Design, Synthesis, Biological Activity, and Structural Analysis of Novel Des-C-Ring and Aromatic-D-Ring Analogues of 1α,25-Dihydroxyvitamin D3

The toxic calcemic effects of the natural hormone 1α,25-dihydroxyvitamin D₃ (1,25D₃, 1,25-dihydroxycholecalciferol) in the treatment of hyperproliferative diseases demand the development of highly active and noncalcemic vitamin D analogues. We report the development of two highly active and noncalcemic analogues of 1,25D₃ that lack the C-ring and possess an m-phenylene ring that replaces the natural D-ring. The new analogues (3a, 3b) are characterized by an additional six-carbon hydroxylated side chain attached either to the aromatic nucleus or to the triene system. Both compounds were synthesized by the Pd-catalyzed tandem cyclization/cross coupling approach starting from alkyne 6 and diphenol 8. Key steps include a stereoselective Cu-assisted addition of a Grignard reagent to an aromatic alkyne and a Takai olefination of an aromatic aldehyde. The new compounds are noncalcemic and show transcriptional and antiproliferative activities similar to 1,25D₃. Structural analysis revealed that they induce a large conformational rearrangement of the vitamin D receptor around helix 6.

EWS/FLI mediated reprogramming of 3D chromatin promotes an altered transcriptional state in Ewing sarcoma

Ewing sarcoma is a prototypical fusion transcription factor-associated pediatric cancer that expresses EWS/FLI or a highly related FET/ETS chimera. EWS/FLI dysregulates transcription to induce and maintain sarcomagenesis, but the mechanisms utilized are not fully understood. We therefore sought to define the global effects of EWS/FLI on chromatin conformation and transcription in Ewing sarcoma cells using a well-validated ‘knock-down/rescue’ model of EWS/FLI function in combination with next generation sequencing assays to evaluate how the chromatin landscape changes with loss, and recovery, of EWS/FLI expression. We found that EWS/FLI (and EWS/ERG) genomic localization is largely conserved across multiple patient-derived Ewing sarcoma cell lines. This EWS/FLI binding signature is associated with establishment of topologically-associated domain (TAD) boundaries, compartment activation, enhancer-promoter looping that involve both intra- and inter-TAD interactions, and gene activation. In addition, EWS/FLI co-localizes with the loop-extrusion factor cohesin to promote chromatin loops and TAD boundaries. Importantly, local chromatin features provide the basis for transcriptional heterogeneity in regulation of direct EWS/FLI target genes across different Ewing sarcoma cell lines. These data demonstrate a key role of EWS/FLI in mediating genome-wide changes in chromatin configuration and support the notion that fusion transcription factors serve as master regulators of three-dimensional reprogramming of chromatin.

GFI1B acts as a metabolic regulator in hematopoiesis and acute myeloid leukemia

Recent studies highlighted the role of transcription factors in metabolic regulation during hematopoiesis and leukemia development. GFI1B is a transcriptional repressor that plays a critical role in hematopoiesis, and its expression is negatively related to the prognosis of acute myeloid leukemia (AML) patients. We earlier reported a change in the metabolic state of hematopoietic stem cells upon Gfi1b deletion. Here we explored the role of Gfi1b in metabolism reprogramming during hematopoiesis and leukemogenesis. We demonstrated that Gfi1b deletion remarkably activated mitochondrial respiration and altered energy metabolism dependence toward oxidative phosphorylation (OXPHOS). Mitochondrial substrate dependency was shifted from glucose to fatty acids upon Gfi1b deletion via upregulating fatty acid oxidation (FAO). On a molecular level, Gfi1b epigenetically regulated multiple FAO-related genes. Moreover, we observed that metabolic phenotypes evolved as cells progressed from preleukemia to leukemia, and the correlation between Gfi1b expression level and metabolic phenotype was affected by genetic variations in AML cells. FAO or OXPHOS inhibition significantly impeded leukemia progression of Gfi1b-KO MLL/AF9 cells. Finally, we showed that Gfi1b-deficient AML cells were more sensitive to metformin as well as drugs implicated in OXPHOS and FAO inhibition, opening new potential therapeutic strategies.

The theory of tumor ecosystem

Cancer cells can be conceived as “living organisms” interacting with cellular or non‐cellular components in the host internal environment, not only the local tumor microenvironment but also the distant organ niches, as well as the immune, nervous and endocrine systems, to construct a self‐sustainable tumor ecosystem. With increasing evidence for the systemic tumor‐host interplay, we predict that a new era of cancer therapy targeting the ecosystemic vulnerability of human malignancies has come. Revolving around the tumor ecosystem scoped as different hierarchies of primary, regional, distal and systemic onco‐spheres, we comprehensively review the tumor‐host interaction among cancer cells and their local microenvironment, distant organ niches, immune, nervous and endocrine systems, highlighting material and energy flow with tumor ecological homeostasis as an internal driving force. We also substantiate the knowledge of visualizing, modelling and subtyping this dynamically intertwined network with recent technological advances, and discuss ecologically rational strategies for more effective cancer therapies.

Translation initiation factor eIF3a regulates glucose metabolism and cell proliferation via promoting small GTPase Rheb synthesis and AMPK activation

Eukaryotic translation initiation factor 3 subunit A (eIF3a), the largest subunit of the eIF3 complex, has been shown to be overexpressed in malignant cancer cells, potentially making it a proto-oncogene. eIF3a overexpression can drive cancer cell proliferation but contributes to better prognosis. While its contribution to prognosis was previously shown to be due to its function in suppressing synthesis of DNA damage repair proteins, it remains unclear how eIF3a regulates cancer cell proliferation. In this study, we show using genetic approaches that eIF3a controls cell proliferation by regulating glucose metabolism via the phosphorylation and activation of AMP-activated protein kinase alpha (AMPKα) at Thr¹⁷² in its kinase activation loop. We demonstrate that eIF3a regulates AMPK activation mainly by controlling synthesis of the small GTPase Rheb, largely independent of the well-known AMPK upstream liver kinase B1 and Ca²⁺/calmodulin-dependent protein kinase kinase 2, and also independent of mammalian target of rapamycin signaling and glucose levels. Our findings suggest that glucose metabolism in and proliferation of cancer cells may be translationally regulated via a novel eIF3a–Rheb–AMPK signaling axis.

Paraneoplastic autoimmune hypophysitis: An emerging concept

Pituitary autoimmunity is one of the principal causes of hypopituitarism. Additionally, hypophysitis is one of the immune-related adverse events associated with immunotherapy. Recent case-oriented research has revealed a novel type of autoimmune hypophysitis, anti-PIT-1 hypophysitis, related to isolated adrenocorticotropic hormone (ACTH) deficiency and immune checkpoint inhibitor-related hypophysitis, as a form of paraneoplastic syndrome. Under these conditions, the ectopic expression of pituitary antigens present in tumors evokes a breakdown of immune tolerance, resulting in the production of autoantibodies and autoreactive cytotoxic T cells that specifically harm pituitary cells. Consequently, an innovative clinical entity of paraneoplastic autoimmune hypophysitis has been purported. This novel concept and its underlying mechanisms provide clues for understanding the pathogenesis of autoimmune pituitary diseases and can be applied to other autoimmune diseases. This review discusses the etiology of paraneoplastic autoimmune hypophysitis and its future.

Noncoding RNAs in the Glycolysis of Ovarian Cancer

Energy metabolism reprogramming is the characteristic feature of tumors. The tumorigenesis, metastasis, and drug resistance of ovarian cancer (OC) is dependent on energy metabolism. Even under adequate oxygen conditions, OC cells tend to convert glucose to lactate, and glycolysis can rapidly produce ATP to meet their metabolic energy needs. Non-coding RNAs (ncRNAs) interact directly with DNA, RNA, and proteins to function as an essential regulatory in gene expression and tumor pathology. Studies have shown that ncRNAs regulate the process of glycolysis by interacting with the predominant glycolysis enzyme and cellular signaling pathway, participating in tumorigenesis and progression. This review summarizes the mechanism of ncRNAs regulation in glycolysis in OC and investigates potential therapeutic targets.

Expression of HK2, PKM2, and PFKM Is Associated with Metastasis and Late Disease Onset in Breast Cancer Patients

The reprogramming of energy metabolism is one of the hallmarks of cancer and is crucial for tumor progression. Altered aerobic glycolysis is a well-known characteristic of cancer cell metabolism. In the present study, the expression profiles of key metabolic genes (HK2, PFKM, and PKM2) were assessed in the breast cancer cohort of Pakistan using quantitative polymerase chain reaction (qPCR) and IHC. Expression patterns were correlated with molecular subtypes and clinical parameters in the patients. A significant upregulation of key glycolytic genes was observed in tumor samples in comparison to their adjacent controls (p < 0.0001). The expression of the studied glycolytic genes was significantly increased in late clinical stages, positive nodal involvement, and distant metastasis (p < 0.05). HK2 and PKM2 were found to be upregulated in luminal B, whereas PFKM was overexpressed in the luminal A subtype of breast cancer. The genes were positively correlated with the proliferation marker Ki67 (p < 0.001). Moreover, moderate positive linear correlations between HK2 and PKM2 (r = 0.476), HK2 and PFKM (r = 0.473), and PKM2 and PFKM (r = 0.501) were also observed (p < 0.01). These findings validate that the key regulatory genes in glycolysis can serve as potential biomarkers and/or molecular targets for breast cancer management. However, the clinical significance of these molecules needs to be further validated through in vitro and in vivo experiments.

Hallmarks of Metabolic Reprogramming and Their Role in Viral Pathogenesis

Metabolic reprogramming is a hallmark of cancer and has proven to be critical in viral infections. Metabolic reprogramming provides the cell with energy and biomass for large-scale biosynthesis. Based on studies of the cellular changes that contribute to metabolic reprogramming, seven main hallmarks can be identified: (1) increased glycolysis and lactic acid, (2) increased glutaminolysis, (3) increased pentose phosphate pathway, (4) mitochondrial changes, (5) increased lipid metabolism, (6) changes in amino acid metabolism, and (7) changes in other biosynthetic and bioenergetic pathways. Viruses depend on metabolic reprogramming to increase biomass to fuel viral genome replication and production of new virions. Viruses take advantage of the non-metabolic effects of metabolic reprogramming, creating an anti-apoptotic environment and evading the immune system. Other non-metabolic effects can negatively affect cellular function. Understanding the role metabolic reprogramming plays in viral pathogenesis may provide better therapeutic targets for antivirals.