Ovarian clear cell carcinoma meets metabolism; HNF-1β confers survival benefits through the Warburg effect and ROS reduction

Cell-free ascites from ovarian cancer patients induces Warburg metabolism and cell proliferation through TGFβ-ERK signaling

Ascites plays a key role in supporting the metastatic potential of ovarian cancer cells. Shear stress and carry-over of cancer cells by ascites flow support carcinogenesis and metastasis formation. In addition, soluble factors may participate in the procarcinogenic effects of ascites in ovarian cancer. This study aimed to determine the biological effects of cell-free ascites on carcinogenesis in ovarian cancer cells. Cell-free ascites from ovarian cancer patients (ASC) non-selectively induced cell proliferation in multiple models of ovarian cancer and untransformed primary human dermal fibroblasts. Furthermore, ASC induced a Warburg-type rearrangement of cellular metabolism in A2780 ovarian cancer cells characterized by increases in cellular oxygen consumption and glycolytic flux; increases in glycolytic flux were dominant. ASC induced mitochondrial uncoupling and fundamentally reduced fatty acid oxidation. Ascites-elicited effects were uniform among ascites specimens. ASC-elicited transcriptomic changes in A2780 ovarian cancer cells included induction of the TGFβ-ERK/MEK pathway, which plays a key role in inducing cell proliferation and oncometabolism. ASC-induced gene expression changes, as well as the overexpression of members of the TGFβ signaling system, were associated with poor survival in ovarian cancer patients. We provided evidence that the activation of the autocrine/paracrine of TGFβ signaling system may be present in bladder urothelial carcinoma and stomach adenocarcinoma. Database analysis suggests that the TGFβ system may feed forward bladder urothelial carcinoma and stomach adenocarcinoma. Soluble components of ASC support the progression of ovarian cancer. These results suggest that reducing ascites production may play an essential role in the treatment of ovarian cancer by inhibiting the progression and reducing the severity of the disease.

From clinical management to personalized medicine: novel therapeutic approaches for ovarian clear cell cancer

Ovarian clear-cell cancer is a rare subtype of epithelial ovarian cancer with unique clinical and biological features. Despite optimal cytoreductive surgery and platinum-based chemotherapy being the standard of care, most patients experience drug resistance and a poor prognosis. Therefore, novel therapeutic approaches have been developed, including immune checkpoint blockade, angiogenesis-targeted therapy, ARID1A synthetic lethal interactions, targeting hepatocyte nuclear factor 1β, and ferroptosis. Refining predictive biomarkers can lead to more personalized medicine, identifying patients who would benefit from chemotherapy, targeted therapy, or immunotherapy. Collaboration between academic research groups is crucial for developing prognostic outcomes and conducting clinical trials to advance treatment for ovarian clear-cell cancer. Immediate progress is essential, and research efforts should prioritize the development of more effective therapeutic strategies to benefit all patients.

The role of mitochondrial dynamics in the pathophysiology of endometriosis

AIM

Endometriosis is a chronic disease of reproductive age, associated with pelvic pain and infertility. Endometriotic cells adapt to changing environments such as oxidative stress and hypoxia in order to survive. However, the underlying mechanisms remain to be fully elucidated. In this review, we summarize our current understanding of the pathogenesis of endometriosis, focusing primarily on the molecular basis of energy metabolism, redox homeostasis, and mitochondrial function, and discuss perspectives on future research directions.

METHODS

Papers published up to March 31, 2023 in the PubMed and Google Scholar databases were included in this narrative literature review.

RESULTS

Mitochondria serve as a central hub sensing a multitude of physiological processes, including energy production and cellular redox homeostasis. Under hypoxia, endometriotic cells favor glycolysis and actively produce pyruvate, nicotinamide adenine dinucleotide phosphate (NADPH), and other metabolites for cell proliferation. Mitochondrial fission and fusion dynamics may regulate the phenotypic plasticity of cellular energy metabolism, that is, aerobic glycolysis or OXPHOS. Endometriotic cells have been reported to have reduced mitochondrial numbers, increased lamellar cristae, improved energy efficiency, and enhanced cell proliferation and survival. Increased mitochondrial fission and fusion turnover by hypoxic and normoxic conditions suggests an activation of mitochondrial quality control mechanisms. Recently, candidate molecules that influence mitochondrial dynamics have begun to be identified.

CONCLUSION

This review suggests that unique energy metabolism and redox homeostasis driven by mitochondrial dynamics may be linked to the pathophysiology of endometriosis. However, further studies are needed to elucidate the regulatory mechanisms of mitochondrial dynamics in endometriosis.

Predicting Prognosis and Platinum Resistance in Ovarian Cancer: Role of Immunohistochemistry Biomarkers

Ovarian cancer is a lethal reproductive tumour affecting women worldwide. The advancement in presentation and occurrence of chemoresistance are the key factors for poor survival among ovarian cancer women. Surgical debulking was the mainstay of systemic treatment for ovarian cancer, which was followed by a successful start to platinum-based chemotherapy. However, most women develop platinum resistance and relapse within six months of receiving first-line treatment. Thus, there is a great need to identify biomarkers to predict platinum resistance before enrolment into chemotherapy, which would facilitate individualized targeted therapy for these subgroups of patients to ensure better survival and an improved quality of life and overall outcome. Harnessing the immune response through immunotherapy approaches has changed the treatment way for patients with cancer. The immune outline has emerged as a beneficial tool for recognizing predictive and prognostic biomarkers clinically. Studying the tumour microenvironment (TME) of ovarian cancer tissue may provide awareness of actionable targets for enhancing chemotherapy outcomes and quality of life. This review analyses the relevance of immunohistochemistry biomarkers as prognostic biomarkers in predicting chemotherapy resistance and improving the quality of life in ovarian cancer.

Recent advances in understanding the metabolic plasticity of ovarian cancer: A systematic review

Epithelial ovarian cancer (EOC) is a gynecologic malignancy with a poor prognosis due to resistance to first-line chemotherapeutic agents. Some cancer cells are primarily dependent on glycolysis, but others favor mitochondrial oxidative phosphorylation (OXPHOS) over glycolysis. Changes in metabolic reprogramming have been reported to be involved in cancer cell survival. In this review, we summarize the metabolic profiles (e.g., metabolic heterogeneity, plasticity, and reprogramming) and adaptation to the dynamic tumor microenvironment and discuss potential novel therapeutic strategies. A literature search was performed between January 2000 and March 2022 in the PubMed and Google Scholar databases using a combination of specific terms. Ovarian cancer cells, including cancer stem cells, depend on glycolysis, OXPHOS, or both for survival. Several environmental stresses, such as nutrient starvation or glucose deprivation, hypoxic stress, acidification, and excessive reactive oxygen species (ROS) generation, reprogram the metabolic pathways to adapt. The interaction between tumors and adjacent stromal cells allows cancer cells to enhance mitochondrial energy metabolism. The metabolic reprogramming varies depending on genomic and epigenetic alterations of metabolism-related genes and the metabolic environment. Developing accurate and non-invasive methods for early identification of metabolic alterations could facilitate optimal cancer diagnosis and treatment. Cancer metabolism research has entered an exciting era where novel strategies targeting metabolic profiling will become more innovative.

Targeting DNA Damage Response Pathway in Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is one of the major types of ovarian cancer and is of higher relative prevalence in Asians. It also shows higher possibility of resistance to cisplatin-based chemotherapy leading to poor prognosis. This may be attributed to the relative lack of mutations and aberrations in homologous recombination-associated genes, which are crucial in DNA damage response (DDR), such as BRCA1, BRCA2, p53, RAD51, and genes in the Fanconi anemia pathway. On the other hand, OCCC is characterized by a number of genetic defects rendering it vulnerable to DDR-targeting therapy, which is emerging as a potent treatment strategy for various cancer types. Mutations of ARID1A, PIK3CA, PTEN, and catenin beta 1 (CTNNB1), as well as overexpression of transcription factor hepatocyte nuclear factor-1β (HNF-1β), and microsatellite instability are common in OCCC. Of particular note is the loss-of-function mutations in ARID1A, which is found in approximately 50% of OCCC. ARID1A is crucial for processing of DNA double-strand break (DSB) and for sustaining DNA damage signaling, rendering ARID1A-deficient cells prone to impaired DNA damage checkpoint regulation and hence sensitive to poly ADP ribose polymerase (PARP) inhibitors. However, while preclinical studies have demonstrated the possibility to exploit DDR deficiency in OCCC for therapeutic purpose, progress in clinical application is lagging. In this review, we will recapitulate the preclinical studies supporting the potential of DDR targeting in OCCC treatment, with emphasis on the role of ARID1A in DDR. Companion diagnostic tests (CDx) for predicting susceptibility to PARP inhibitors are rapidly being developed for solid tumors including ovarian cancers and may readily be applicable on OCCC. The potential of various available DDR-targeting drugs for treating OCCC by drawing analogies with other solid tumors sharing similar genetic characteristics with OCCC will also be discussed.

Hepatocyte nuclear factor-1β shapes the energetic homeostasis of kidney tubule cells

Energetic metabolism controls key steps of kidney development, homeostasis, and epithelial repair following acute kidney injury (AKI). Hepatocyte nuclear factor-1β (HNF-1β) is a master transcription factor that controls mitochondrial function in proximal tubule (PT) cells. Patients with HNF1B pathogenic variant display a wide range of kidney developmental abnormalities and progressive kidney fibrosis. Characterizing the metabolic changes in PT cells with HNF-1β deficiency may help to identify new targetable molecular hubs involved in HNF1B-related kidney phenotypes and AKI. Here, we combined ¹ H-NMR-based metabolomic analysis in a murine PT cell line with CrispR/Cas9-induced Hnf1b invalidation (Hnf1b^-/- ), clustering analysis, targeted metabolic assays, and datamining of published RNA-seq and ChIP-seq dataset to identify the role of HNF-1β in metabolism. Hnf1b^-/- cells grown in normoxic conditions display intracellular ATP depletion, increased cytosolic lactate concentration, increased lipid droplet content, failure to use pyruvate for energetic purposes, increased levels of tricarboxylic acid (TCA) cycle intermediates and oxidized glutathione, and a reduction of TCA cycle byproducts, all features consistent with mitochondrial dysfunction and an irreversible switch toward glycolysis. Unsupervised clustering analysis showed that Hnf1b^-/- cells mimic a hypoxic signature and that they cannot furthermore increase glycolysis-dependent energetic supply during hypoxic challenge. Metabolome analysis also showed alteration of phospholipid biosynthesis in Hnf1b^-/- cells leading to the identification of Chka, the gene coding for choline kinase α, as a new putative target of HNF-1β. HNF-1β shapes the energetic metabolism of PT cells and HNF1B deficiency in patients could lead to a hypoxia-like metabolic state precluding further adaptation to ATP depletion following AKI.

Isothiocyanate Iberin inhibits cell proliferation and induces cell apoptosis in the progression of ovarian cancer by mediating ROS accumulation and GPX1 expression

Ovarian cancer (OC) is one of the most common gynecologic malignancies with poor survival rate, and Iberin is a member of isothiocyanate family with anti-tumor activity. However, the role of Iberin in OC development has not been reported yet. In this study, A2780 and OVCAR-3 cells were treated with gradient concentrations of Iberin to investigate the effect of Iberin on OC in vitro. Meanwhile, the in vivo tumorgenesis experiment was performed using female BALB/c nude mice treated with Iberin. Iberin inhibited cell proliferation, induced G2 cell cycle arrest and promoted cell apoptosis in OC cells. Besides, Iberin reduced GSH/GSSG level, enhanced ROS accumulation, and activated MAPK signaling in OC cells. More interestingly, ROS scavenger (NAC) compensated the anti-proliferative and pro-apoptotic effects of Iberin on OC cells, suggesting the involvement of ROS in the regulation of Iberin on OC cell growth. Notably, Iberin induced down-regulation of glutathione peroxidase-1 (GPX1), and over-expression of GPX1 reversed Iberin-mediated alterations in the proliferation, apoptosis and ROS accumulation of OC cells. The in vivo tumorgenesis study further evidenced the protection of Iberin against OC development. Besides, Iberin displayed a synergistic effect on the enhancement of chemo-sensitivity in OC cells. In summary, our study demonstrates the anti-tumor effect of Iberin on OC and its potential as a therapeutic agent against OC in the future.

Nicotinamide N-Methyltransferase: An Emerging Protagonist in Cancer Macro(r)evolution

Nicotinamide N-methyltransferase (NNMT) has progressed from being considered merely a Phase II metabolic enzyme to one with a central role in cell function and energy metabolism. Over the last three decades, a significant body of evidence has accumulated which clearly demonstrates a central role for NNMT in cancer survival, metastasis, and drug resistance. In this review, we discuss the evidence supporting a role for NNMT in the progression of the cancer phenotype and how it achieves this by driving the activity of pro-oncogenic NAD+-consuming enzymes. We also describe how increased NNMT activity supports the Warburg effect and how it promotes oncogenic changes in gene expression. We discuss the regulation of NNMT activity in cancer cells by both post-translational modification of the enzyme and transcription factor binding to the NNMT gene, and describe for the first time three long non-coding RNAs which may play a role in the regulation of NNMT transcription. We complete the review by discussing the development of novel anti-cancer therapeutics which target NNMT and provide insight into how NNMT-based therapies may be best employed clinically.

Metabolic reprogramming in epithelial ovarian cancer

Cancer cells usually show adaptations to their metabolism that facilitate their growth, invasiveness, and metastasis. Therefore, reprogramming the energy metabolism is one of the current key foci of cancer research and treatment. Although aerobic glycolysis-the Warburg effect-has been thought to be the dominant energy metabolism in cancer, recent data indicate a different possibility, specifically that oxidative phosphorylation (OXPHOS) is the more likely form of energy metabolism in some cancer cells. Due to the heterogeneity of epithelial ovarian cancer, there are different metabolic preferences among cell types, study types (in vivo/in vitro), and invasiveness. Current knowledge acknowledges glycolysis to be the main energy provider in ovarian cancer growth, invasion, migration, and viability, so specific agents targeting the glycolysis or OXPHOS pathways have been used in previous studies to attenuate tumor progression and increase chemosensitization. However, chemoresistant cell lines exert various metabolic preferences. This review comprehensively summarizes the information from existing reports which could together provide an in-depth understanding and insights for the development of a novel targeted therapy which can be used as an adjunctive treatment to standard chemotherapy to decelerate tumor progression and decrease the epithelial ovarian cancer mortality rate.

Toward an understanding of tissue factor pathway inhibitor-2 as a novel serodiagnostic marker for clear cell carcinoma of the ovary

AIMS

Tissue factor pathway inhibitor (TFPI)-2 has recently emerged as a serodiagnostic marker for patients with epithelial ovarian cancer (EOC), especially clear cell carcinoma (CCC). This review discusses the biological properties of TFPI-2 and why serum levels are elevated in CCC patients.

METHODS

A comprehensive literature search was conducted in PubMed up until March, 2021.

RESULTS

TFPI-2 is a Kunitz-type protease inhibitor and negatively regulates the enzymatic activities, such as plasmin. TFPI-2 has been characterized as a tumor suppressor gene and was frequently downregulated through promoter hypermethylation in various human cancers. In contrast, TFPI-2 was overexpressed only in CCC. TFPI-2 may be involved in the pathophysiology of CCC, possibly through regulation of coagulation system, stabilization of extracellular matrix (ECM), and induction of intracellular signal transduction. TFPI-2 suppresses tissue factor-induced hypercoagulation in a hypoxic environment. TFPI-2, secreted by CCC cells, platelets, and adjacent vascular endothelial cells, may suppress tumor growth and invasion through ECM remodeling. Nuclear TFPI-2 may suppress matrix metalloproteinase production via transcription factors and modulate caspase-mediated cell apoptosis. CCC cells may upregulate the TFPI-2 expression to adapt to survival in the demanding environment. TFPI-2 is secreted by CCC cells and enters the systemic circulation, resulting in elevated blood levels.

DISCUSSION

Serum TFPI-2 reflects the overexpression of TFPI-2 in CCC tissues and is a potential serodiagnostic marker. Further research is needed to explore the expression, clinical significance, biological function, and potential mechanism of TFPI-2 in CCC.

Updates of Pathogenesis, Diagnostic and Therapeutic Perspectives for Ovarian Clear Cell Carcinoma

Ovarian clear cell carcinoma (OCCC) is a special pathological type of epithelial ovarian carcinoma (EOC) and has a high prevalence in Asia without specific molecular subtype classification. Endometriosis is a recognized precancerous lesion that carries 3-fold increased risk of OCCC. Ovarian endometrioid carcinoma, which also originates from endometriosis, shares several features with OCCC, including platinum resistance and younger age at diagnosis. Patients with OCCC have about a 2.5 to 4 times greater risk of having a venous thromboembolism (VTE) compared with other EOC, and OCCC tends to metastasize through lymphatic vesicular and peritoneal spread as opposed to hematogenous metastasis. There is only mild elevation of the conventional biomarker CA125. Staging surgery or optimal cytoreduction combined with chemotherapy is a common therapeutic strategy for OCCC. However, platinum resistance commonly portends a poor prognosis, so novel treatments are urgently needed. Targeted therapy and immunotherapy are currently being studied, including PARP, EZH2, and ATR inhibitors combined with the synthetic lethality of ARID1A-dificiency, and MAPK/PI3K/HER2, VEGF/bFGF/PDGF, HNF1β, and PD-1/PD-L1 inhibitors. Advanced stage, suboptimal cytoreduction, platinum resistance, lymph node metastasis, and VTE are major prognostic predictors for OCCC. We focus on update pathogenesis, diagnostic methods and therapeutic approaches to provide future directions for clinical diagnosis and treatment of OCCC.

Targeting the tumour microenvironment in platinum-resistant ovarian cancer

Ovarian cancer typically presents at an advanced stage, and although the majority of cases initially respond well to platinum-based therapies, chemoresistance almost always occurs leading to a poor long-term prognosis. While various cellular autonomous mechanisms contribute to intrinsic or acquired platinum resistance, the tumour microenvironment (TME) plays a central role in resistance to therapy and disease progression by providing cancer stem cell niches, promoting tumour cell metabolic reprogramming, reducing chemotherapy drug perfusion and promoting an immunosuppressive environment. As such, the TME is an attractive therapeutic target which has been the focus of intense research in recent years. This review provides an overview of the unique ovarian cancer TME and its role in disease progression and therapy resistance, highlighting some of the latest preclinical and clinical data on TME-targeted therapies. In particular, it focuses on strategies targeting cancer-associated fibroblasts, tumour-associated macrophages, cancer stem cells and cancer cell metabolic vulnerabilities.

CPNE1 Enhances Colorectal Cancer Cell Growth, Glycolysis, and Drug Resistance Through Regulating the AKT-GLUT1/HK2 Pathway

Introduction

Colorectal cancer (CRC) is a major cause of cancer-related mortality worldwide. Copines-1 (CPNE1) has been shown to be overexpressed in various cancers; however, the role of CPNE1 in CRC remains unknown. Therefore, it is of great importance to elucidate the role of CPNE1 in CRC and its underlying mechanism of action.

Methods

CPNE1 expression in CRC tissues was measured by quantitative real-time PCR and immunohistochemical (IHC) staining. CPNE1 was knocked down (KD) or overexpressed using small inferring RNAs or lentiviral transduction in CRC cells. The proliferation, apoptosis, glycolysis, and mitochondrial respiration of CRC cells were assessed by cell counting kit-8, flow cytometry, and Xfe24 extracellular flux analyzer assays, respectively. The role of CPNE1 in tumor growth and chemoresistance was further confirmed in xenograft and patient-derived tumor xenograft models, respectively.

Results

CPNE1 mRNA and protein were upregulated in CRC tissues. CPNE1 promoted proliferation, inhibited apoptosis, increased mitochondrial respiration, enhanced aerobic glycolysis by activating AKT signaling, upregulated glucose transporter 1 (GLUT1) and hexokinase 2 (HK2), and downregulated the production of cleaved Caspase-3 (c-Caspase 3). CPNE1 also contributed to chemoresistance in CRC cells. CPNE1 KD inhibited tumor growth and increased the sensitivity of tumors to oxaliplatin in vivo.

Conclusion

CPNE1 promotes CRC progression by activating the AKT-GLUT1/HK2 cascade and enhances chemoresistance.

Risk of second malignancy in patients with ovarian clear cell carcinoma

OBJECTIVE

Ovarian clear cell carcinoma has unique clinical and molecular features compared with other epithelial ovarian cancer histologies. Our objective was to describe the incidence of second primary malignancy in patients with ovarian clear cell carcinoma.

METHODS

Retrospective cohort study of patients with ovarian clear cell carcinoma at two tertiary academic centers in Toronto, Canada between May 1995 and June 2017. Demographic, histopathologic, treatment, and survival details were obtained from chart review and a provincial cancer registry. We excluded patients with histologies other than pure ovarian clear cell carcinoma (such as mixed clear cell histology), and those who did not have their post-operative follow-up at these institutions.

RESULTS

Of 209 patients with ovarian clear cell carcinoma, 54 patients developed a second primary malignancy (25.8%), of whom six developed two second primary malignancies. Second primary malignancies included: breast (13), skin (9), gastrointestinal tract (9), other gynecologic malignancies (8), thyroid (6), lymphoma (3), head and neck (4), urologic (4), and lung (4). Eighteen second primary malignancies occurred before the index ovarian clear cell carcinoma, 35 after ovarian clear cell carcinoma, and 7 were diagnosed concurrently. Two patients with second primary malignancies were diagnosed with Lynch syndrome. Smoking and radiation therapy were associated with an increased risk of second primary malignancy on multivariable analysis (OR 3.69, 95% CI 1.54 to 9.07, p=0.004; OR 4.39, 95% CI 1.88 to 10.6, p=0.0008, respectively). However, for patients developing second primary malignancies after ovarian clear cell carcinoma, radiation therapy was not found to be a significant risk factor (p=0.17). There was no significant difference in progression-free survival (p=0.85) or overall survival (p=0.38) between those with second primary malignancy and those without.

CONCLUSION

Patients with ovarian clear cell carcinoma are at increased risk of second primary malignancies, most frequently non-Lynch related. A subset of patients with ovarian clear cell carcinoma may harbor mutations rendering them susceptible to second primary malignancies. Our results may have implications for counseling and consideration for second primary malignancy screening.

Subtype specific biomarkers associated with chemoresistance in epithelial ovarian cancer

In spite of the advent of many high throughput technologies, tumor tissue biomarkers are still the gold standard for diagnosis and prognosis of different malignancies including epithelial ovarian cancer (EOC). EOC is a heterogeneous disease comprised of five major subtypes which show distinct clinicopathological features and therapy response. Acquirement of chemoresistance toward therapy is a major challenge for successful treatment outcome in EOC patients. Several markers have been tested by immunohistochemical method to evaluate their prognostic merit to predict clinical outcome. However, a vast majority of such markers have been assessed for high-grade serous and clear cell ovarian cancer, among all subtypes of EOC. The current review elaborates upon those biomarkers that can potentially predict chemoresistance with subtype specificity.

Revisiting Glycogen in Cancer: A Conspicuous and Targetable Enabler of Malignant Transformation

Once thought to be exclusively a storage hub for glucose, glycogen is now known to be essential in a range of physiological processes and pathological conditions. Glycogen lies at the nexus of diverse processes that promote malignancy, including proliferation, migration, invasion, and chemoresistance of cancer cells. It is also implicated in processes associated with the tumor microenvironment such as immune cell effector function and crosstalk with cancer-associated fibroblasts to promote metastasis. The enzymes of glycogen metabolism are dysregulated in a wide variety of malignancies, including cancers of the kidney, ovary, lung, bladder, liver, blood, and breast. Understanding and targeting glycogen metabolism in cancer presents a promising but under-explored therapeutic avenue. In this review, we summarize the current literature on the role of glycogen in cancer progression and discuss its potential as a therapeutic target for cancer treatment.

miR-375-3p inhibits the progression of laryngeal squamous cell carcinoma by targeting hepatocyte nuclear factor-1β

Laryngeal squamous cell carcinoma (LSCC) is one of the most frequently diagnosed head and neck cancers worldwide. Increasing evidence suggests that microRNAs (miRNAs/miRs) regulate the progression of tumorigenesis and the malignant behaviors of cancer cells. The aim of this study was to investigate the function and underlying mechanism of miR-375-3p in LSCC. The expression of miR-375-3p in LSCC tissues and cells was detected using reverse transcription-quantitative PCR. The effects of miR-375-3p on the malignant phenotype of LSCC cells was determined using the Cell Counting Kit-8 assay and flow cytometry. The targets of miR-375-3p were predicted using the miRDB database and confirmed by the luciferase reporter assay. The results of the present study demonstrated that miR-375-3p was downregulated in LSCC tissues and cell lines. Furthermore, overexpression of miR-375-3p significantly suppressed the proliferation and cell cycle progression of LSCC cells. Overexpression of miR-375-3p also increased LSCC cell apoptosis. Mechanistical analysis indicated that miR-375-3p bound the 3′-untranslated region of the hepatocyte nuclear factor 1β (HNF1β) and decreased its expression in LSCC cells. Consistent with the role of HNF1β in glucose metabolism, overexpression of miR-375-3p significantly inhibited glucose consumption and lactate production in LSCC cells. Transfection with HNF1β notably reversed the inhibitory effect of miR-375-3p on the proliferation of LSCC cells. Collectively, these results indicate the tumor suppressive role of miR-375-3p in LSCC via HNF1β, suggesting that miR-375-3p may serve as a potential target in the treatment of LSCC.

Peroxidan Plays a Tumor-Promoting Role in Oral Squamous Cell Carcinoma

Despite dramatic progress in cancer diagnosis and treatment, the five-year survival rate of oral squamous cell carcinoma (OSCC) is still only about 50%. Thus, the need for elucidating the molecular mechanisms underlying OSCC is urgent. We previously identified the peroxidasin gene (PXDN) as one of several novel genes associated with OSCC. Although the PXDN protein is known to act as a tumor-promoting factor associated with the Warburg effect, its function and role in OSCC are poorly understood. In this study, we investigated the expression, function, and relationship with the Warburg effect of PXDN in OSCC. In immunohistochemical analysis of OSCC specimens, we observed that elevated PXDN expression correlated with lymph node metastasis and a diffuse invasion pattern. High PXDN expression was confirmed as an independent predictor of poor prognosis by multivariate analysis. The PXDN expression level correlated positively with that of pyruvate kinase (PKM2) and heme oxygenase-1 (HMOX1) and with lactate and ATP production. No relationship between PXDN expression and mitochondrial activation was observed, and PXDN expression correlated inversely with reactive oxygen species (ROS) production. These results suggest that PXDN might be a tumor progression factor causing a Warburg-like effect in OSCC.

Pathology of clear cell carcinoma of the ovary: A basic view based on cultured cells and modern view from comprehensive approaches

Clear cell carcinoma (CCC) is a distinct histologic type of ovarian carcinoma. CCC is more frequent in Japan than in the Western world. CCC is chemo-resistant and often associated with paraneoplastic thromboembolism. Histologically, CCC is characterized by both cancer cells and stromas, being concordant with the cytological features. Clear cells contain abundant glycogen. Hepatocyte nuclear factor-1β is a specific marker of CCC, and is likely to be involved in glucose metabolism. Extracellular matrix (ECM)-deposited stroma and plasma cell-rich inflammatory stroma are characteristic stromas of CCC. Studies using CCC cell lines showed that CCC cells produce ECMs and stimulate plasma cell differentiation in a paracrine manner. Most CCCs, as well as endometrioid carcinomas, originate from ovarian endometriosis. This is supported by molecular genetic data, although it remains unclear why different histologic types originate from the same precursor. CCC and endometrioid carcinoma are Lynch syndrome-associated ovarian carcinomas. Recent comprehensive studies indicate that CCC is distinct not only in terms of histology but also in genomics, epigenomics and transcriptomics. This review summarizes the pathology of ovarian CCC along with a basic view based on cultured cells, and refers to recent genetic and omic data.

Hepatocyte nuclear factor-1 beta protects endometriotic cells against apoptotic cell death by up-regulating the expression of antiapoptotic genes†

The overexpression of hepatocyte nuclear factor-1 beta (HNF1β) in endometriotic lesion has been demonstrated. However, the role of HNF1β in endometriosis remains largely unknown. Human endometriotic 12Z cells showed higher level of HNF1β when compared with normal endometrial HES cells. In human endometriotic 12Z cells, HNF1β knockdown increased susceptibility to apoptotic cell death by oxidative stress, while HNF1β overexpression suppressed apoptosis. In addition, HNF1β knockdown and overexpression significantly decreased and increased, respectively, the expression of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB)-dependent antiapoptotic genes. Knockdown of the antiapoptotic genes significantly reduced the HNF1β-induced resistance against oxidative stress in 12Z cells. Furthermore, HNF1β regulated the transcriptional activity of NF-κB, and an NF-κB inhibitor suppressed the HNF1β-enhanced NF-κB-dependent antiapoptotic gene expression and the resistance of the 12Z cells against cell death. Taken together, these data suggest that HNF1β overexpression may protect endometriotic cells against oxidative damage by augmenting antiapoptotic gene expression.

Hydrogen peroxide-producing NADPH oxidases and the promotion of migratory phenotypes in cancer

The cellular microenvironment plays a critical role in cancer initiation and progression. Exposure to oxidative stress, specifically hydrogen peroxide (H₂O₂), has been linked to aberrant cellular signaling through which the development of cancer may be promoted. Three members of the NADPH oxidase family (NOX4, DUOX1 and DUOX2) explicitly generate this non-radical oxidant in a wide range of tissues, often in support of the inflammatory response. This review summarizes the contributions of each H₂O₂-producing NOX to the invasive behaviors of tumors and/or the epithelial-mesenchymal transition (EMT) in cancer that plays an essential role in metastasis. Tissue localization in tumorigenesis is also highlighted, with patient-derived TCGA microarray data profiled across 31 cancer cohorts to provide a comprehensive guide to the relevance of NOX4/DUOX1/DUOX2 in cancer studies.

Current Position of the Molecular Therapeutic Targets for Ovarian Clear Cell Carcinoma: A Literature Review

Ovarian clear cell carcinoma (OCCC) shows low sensitivity to conventional chemotherapy and has a poor prognosis, especially in advanced stages. Therefore, the development of innovative therapeutic strategies and precision medicine for the treatment of OCCC are important. Recently, several new molecular targets have been identified for OCCC, which can be broadly divided into four categories: (a) downstream pathways of receptor tyrosine kinases, (b) anti-oxidative stress molecules, (c) AT-rich interactive domain 1A-related chromatin remodeling errors, and (d) anti-programmed death ligand 1/programmed cell death 1 agents. Several inhibitors have been discovered for these targets, and the suppression of OCCC cells has been demonstrated both in vitro and in vivo. However, no single inhibitor has shown a sufficient effectiveness in clinical pilot studies. This review outlines recent progress regarding the molecular biological characteristics of OCCC to identify future directions for the development of precision medicine and combinatorial therapies to treat OCCC.

A diagnostic challenge of seromucinous borderline tumor: A case report

INTRODUCTION

Magnetic resonance (MR) relaxometry provides a noninvasive predictive tool to discriminate between benign ovarian endometrioma (OE) and endometriosis-associated ovarian cancer (EAOC). Transverse relaxation rate R2 value was determined using a single-voxel, multi-echo MR sequence (HISTO) by a 3T-MR system. R2 with cutoff value of 12.1 s was established to discriminate between benign and malignant tumors.

PATIENT CONCERNS

We present a case of a 39-year-old woman who was initially thought to be malignant transformation of endometriosis by diagnostic MR imaging of the vascularized solid components.

DIAGNOSIS

A R2 value of 42.62 s on MR relaxometry demonstrated that this case is non-malignant.

INTERVENTIONS

To confirm the diagnose, left salpingo-oophorectomy by laparoscopic surgery was performed.

OUTCOMES

Histopathological results revealed seromucinous borderline tumor (SMBT). Our experience suggests that preoperative MR relaxometry may be useful for discriminating "borderline (SMBT)" from "malignancy (EAOC)." Furthermore, immunohistochemical studies of this case demonstrated ovarian SMBT cells were positive for estrogen receptor, progesterone receptor, and hepatocyte nuclear factor-1beta. A similar expression pattern was also observed in patients with benign OE.

LESSONS

In many respects, SMBT characteristics differ from those of EAOC but resemble those of benign OE. MR relaxometry unveils a new clinical approach as an adjunctive modality for discriminating SMBT from EAOC.

18F-FDG PET/CT-based metabolic metrics in recurrent tumors of ovarian clear cell carcinoma and their prognostic implications

Background

Glucose metabolism has been suggested as a therapeutic target in ovarian clear cell carcinoma (CCC). We attempted to clarify ¹⁸F-FDG PET/CT-based metabolic metrics in the recurrent ovarian CCC patients and their prognostic values.

Methods

Quantitative metabolic parameters included maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG). Two different methods were employed for defining the threshold SUV to delineate MTV: 1) SUV of 2.5 (designated as MTV); 2) a fixed ratio including 40% (MTV40), 50% (MTV50) and 60% (MTV60) of SUVmax. The Kaplan-Meier model and Cox regression were used in survival analysis.

Results

Among the 35 patients, platinum-resistant recurrence accounted for 34.3% and the median progression-free survival was 13 months (range, 2–135). Fifteen (42.9%) patients presented with single tumor recurrence, while 51 recurrent lesions were identified, with the most common sites in pelvis (29.4%), followed by lymph node metastases (19.6%) and peritoneal carcinomatosis (15.7%). Except four patients with FDG-inavid tumor, the median SUVmax of the 31 patients with high glucose metabolic activity was 7.10 (range, 3.00–20.60). After a median follow-up of 36.5 months (range, 7–155), 22 patients (64.7%) were dead from disease. The median post-relapse survival (PRS) was 17 months (range, 4–126). Platinum-resistant recurrence, peritoneal carcinomatosis and high TLG60 proved to be negative predicators of overall survival after multivariate analysis.

Conclusions

TLG60, platinum-resistant recurrence and peritoneal carcinomatosis were independent negative predicators of overall survival. Whether patients with higher TLG60 required more aggressive treatment warranted further study.

Genomics to immunotherapy of ovarian clear cell carcinoma: Unique opportunities for management

Ovarian clear cell carcinoma (OCCC) is distinctive from other histological types of epithelial ovarian cancer, with genetic/epigenetic alterations, a specific immune-related molecular profile, and epidemiologic associations with ethnicity and endometriosis. These findings allow for the exploration of unique and specific treatments for OCCC. Two major mutated genes in OCCC are PIK3CA and ARID1A, which are frequently coexistent with each other. Other genes' alterations also contribute to activation of the PI3K (e.g. PIK3R1 and PTEN) and dysregulation of the chromatin remodeling complex (e.g. ARID1B, and SMARKA4). Although the number of focal copy number variations is small in OCCC, amplification is recurrently detected at chromosome 20q13.2 (including ZNF217), 8q, and 17q. Both expression and methylation profiling highlight the significance of adjustments to oxidative stress and inflammation. In particular, up-regulation of HNF-1β resulting from hypomethylation contributes to the switch from anaerobic to aerobic glucose metabolism. Additionally, up-regulation of HNF-1β activates STAT3 and NF-κB signaling, and leads to immune suppression via production of IL-6 and IL-8. Immune suppression may also be induced by the increased expression of PD-1, Tim-3 and LAG3. Mismatch repair deficient (microsatellite instable) tumors as found in Lynch syndrome also induce immune suppression in some OCCC. In a recent phase II clinical trial in heavily-treated platinum-resistant ovarian cancer, two out of twenty cases with a complete response to the anti-PD-1 antibody, nivolumab, were OCCC subtypes. Thus, the immune-suppressive state resulting from both genetic alterations and the unique tumor microenvironment may be associated with sensitivity to immune checkpoint inhibitors in OCCC. In this review, we highlight recent update and progress in OCCC from both the genomic and immunologic points of view, addressing the future candidate therapeutic options.

ADAM9 is over-expressed in human ovarian clear cell carcinomas and suppresses cisplatin-induced cell death

ADAMs (a disintegrin and metalloproteinases) are involved in various biological events such as cell adhesion, migration and invasion, membrane protein shedding and proteolysis. However, there have been no systematic studies on the expression of ADAMs in human ovarian carcinomas. We therefore examined mRNA expression of all the proteolytic ADAM species including ADAM8, 9, 10, 12, 15, 17, 19, 20, 21, 28, 30, 33 and ADAMDEC1 in human ovarian carcinomas, and found that prototype membrane-anchored ADAM9m, but not secreted isoform ADAM9s, is significantly over-expressed in carcinomas than in control non-neoplastic ovarian tissue. Among the histological subtypes of serous, endometrioid, mucinous and clear cell carcinomas, ADAM9m expression was highest in clear cell carcinomas. Immunohistochemistry showed that all the clear cell carcinoma samples displayed ADAM9m primarily on the carcinoma cell membrane. By immunoblotting, ADAM9m was detected mainly in an active form in the clear cell carcinoma tissues. When two clear cell carcinoma cell lines (RMG-I and TOV21G cells) with ADAM9m expression were treated with cisplatin, viability was significantly reduced and apoptosis increased in ADAM9m knockdown cells compared with mock transfectants. In addition, treatment of the cells with neutralizing anti-ADAM9m antibody significantly decreased viability compared with non-immune IgG, whereas ADAM9m over-expression significantly increased viability compared with mock transfectants. Our data show, to the best of our knowledge, for the first time, that ADAM9m is over-expressed in an activated form in human ovarian clear cell carcinomas, and suggest that ADAM9m plays a key role in cisplatin resistance.

Dichloroacetate and metformin synergistically suppress the growth of ovarian cancer cells

Both dichloroacetate (DCA) and metformin (Met) have shown promising antitumor efficacy by regulating cancer cell metabolism. However, the DCA-mediated protective autophagy and Met-induced lactate accumulation limit their tumor-killing potential respectively. So overcoming the corresponding shortages will improve their therapeutic effects. In the present study, we found that DCA and Met synergistically inhibited the growth and enhanced the apoptosis of ovarian cancer cells. Interestingly, we for the first time revealed that Met sensitized DCA via dramatically attenuating DCA-induced Mcl-1 protein and protective autophagy, while DCA sensitized Met through markedly alleviating Met-induced excessive lactate accumulation and glucose consumption. The in vivo experiments in nude mice also showed that DCA and Met synergistically suppressed the growth of xenograft ovarian tumors. These results may pave a way for developing novel strategies for the treatment of ovarian cancer based on the combined use of DCA and Met.

Update on rare epithelial ovarian cancers: based on the Rare Ovarian Tumors Young Investigator Conference

There has been significant progress in the understanding of the pathology and molecular biology of rare ovarian cancers, which has helped both diagnosis and treatment. This paper provides an update on recent advances in the knowledge and treatment of rare ovarian cancers and identifies gaps that need to be addressed by further clinical research. The topics covered include: low-grade serous, mucinous, and clear cell carcinomas of the ovary. Given the molecular heterogeneity and the histopathological rarity of these ovarian cancers, the importance of designing adequately powered trials or finding statistically innovative ways to approach the treatment of these rare tumors has been emphasized. This paper is based on the Rare Ovarian Tumors Conference for Young Investigators which was presented in Tokyo 2015 prior to the 5th Ovarian Cancer Consensus Conference of the Gynecologic Cancer InterGroup (GCIG).

Hepatocyte Nuclear Factor-1β Controls Mitochondrial Respiration in Renal Tubular Cells

AKI is a frequent condition that involves renal microcirculation impairment, infiltration of inflammatory cells with local production of proinflammatory cytokines, and subsequent epithelial disorders and mitochondrial dysfunction. Peroxisome proliferator-activated receptor γ coactivator 1-α (PPARGC1A), a coactivator of the transcription factor PPAR-γ that controls mitochondrial biogenesis and function, has a pivotal role in the early dysfunction of the proximal tubule and the subsequent renal repair. Here, we evaluated the potential role of hepatocyte nuclear factor-1β (HNF-1β) in regulating PPARGC1A expression in AKI. In mice, endotoxin injection to induce AKI also induced early and transient inflammation and PPARGC1A inhibition, which overlapped with downregulation of the HNF-1β transcriptional network. In vitro, exposure of proximal tubule cells to the inflammatory cytokines IFN-γ and TNF-α led to inhibition of HNF-1β transcriptional activity. Moreover, inhibition of HNF-1β significantly reduced PPARGC1A expression and altered mitochondrial morphology and respiration in proximal tubule cells. Chromatin immunoprecipitation assays and PCR analysis confirmed HNF-1β binding to the Ppargc1a promoter in mouse kidneys. We also demonstrated downregulation of renal PPARGC1A expression in a patient with an HNF1B germinal mutation. Thus, we propose that HNF-1β links extracellular inflammatory signals to mitochondrial dysfunction during AKI partly via PPARGC1A signaling. Our findings further strengthen the view of HNF1B-related nephropathy as a mitochondrial disorder in adulthood.

Inhibition of COX2 enhances the chemosensitivity of dichloroacetate in cervical cancer cells

Dichloroacetate (DCA), a traditional mitochondria-targeting agent, has shown promising prospect as a sensitizer in fighting against malignancies including cervical cancer. But it is unclear about the effect of DCA alone on cervical tumor. Moreover, previous reports have demonstrated that the increased cyclooxygenase-2 (COX2) expression is associated with chemoresistance and poor prognosis of cervical cancer. However, it is still unknown whether COX2 can affect the sensitivity of DCA in cervical cancer cells. In this study, we found that cervical cancer cells were insensitive to DCA. Furthermore, we for the first time revealed that DCA could upregulate COX2 which impeded the chemosensitivity of DCA in cervical cancer cells. Mechanistic study showed that DCA reduced the level of RNA binding protein quaking (QKI), leading to the decay suppression of COX2 mRNA and the subsequent elevation of COX2 protein. Inhibition of COX2 using celecoxib could sensitize DCA in repressing the growth of cervical cancer cells both in vitro and in vivo. These results indicate that COX2 is a novel resistance factor of DCA, and combination of celecoxib with DCA may be beneficial to the treatment of cervical cancer.

Dicumarol inhibits PDK1 and targets multiple malignant behaviors of ovarian cancer cells

Pyruvate dehydrogenase kinase 1 (PDK1) is overexpressed in ovarian cancer and thus is a promising anticancer therapeutic target. Our previous work suggests that coumarin compounds are potential inhibitors of PDKs. In this study, we used the ovarian cancer cell line SKOV3 as the model system and examined whether dicumarol (DIC), a coumarin compound, could inhibit ovarian cancer through targeting PDK1. We showed that DIC potently inhibited the kinase activity of PDK1, shifted the glucose metabolism from aerobic glycolysis to oxidative phosphorylation, generated a higher level of reactive oxygen species (ROS), attenuated the mitochondrial membrane potential (MMP), induced apoptosis, and reduced cell viability in vitro. The same phenotypes induced by DIC also were translated in vivo, leading to significant suppression of xenograft growth. This study not only identifies a novel inhibitor for PDK1, but it also reveals novel anticancer mechanisms of DIC and provides a promising anticancer therapy that targets the Warburg effect.

MicroRNA-124 suppresses proliferation and glycolysis in non-small cell lung cancer cells by targeting AKT-GLUT1/HKII

Non-small cell lung cancer accounts for 85% of all types of lung cancer and is the leading cause of worldwide cancer-associated mortalities. MiR-124 is epigenetically silenced in various types of cancer and plays important roles in tumor development and progression. MiR-124 was also significantly downregulated in non-small cell lung cancer patients. Glycolysis has been considered as a feature of cancer cells; hypoxia-inducible factor 1-alpha/beta and Akt are key enzymes in the regulation of glycolysis and energy metabolism in cancer cells. However, the role of miR-124 in non-small cell lung cancer cell proliferation, glycolysis, and energy metabolism remains unknown. In this research, cell proliferation was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; furthermore, glucose consumption and lactic acid production were assessed; adenosine triphosphate content and NAD⁺/NADH were also detected. These tests were conducted using the normal non-small cell lung cancer cell line A549, which was transfected variedly with miR-mimics, miR-124 mimics, miR-124 inhibitor, pc-DNA3.1(+)-AKT1, and pc-DNA3.1(+)-AKT2 plasmid. Here, we show that miR-124 overexpression directly decreased cell growth, glucose consumption, lactate production, and energy metabolism. MiR-124 also negatively regulates glycolysis rate-limiting enzymes, glucose transporter 1 and hexokinase II. Our results also showed that miR-124 negatively regulates AKT1 and AKT2 but no regulatory effect on hypoxia-inducible factor 1-alpha/beta. Overexpression of AKT reverses the inhibitory effect of miR-124 on cell proliferation and glycolytic metabolism in non-small cell lung cancer. AKT inhibition blocks miR-124 silencing-induced AKT1/2, glucose transporter 1, hexokinase II activation, cell proliferation, and glycolytic or energy metabolism changes. In summary, this study demonstrated that miR-124 is able to inhibit proliferation, glycolysis, and energy metabolism, potentially by targeting AKT1/2-glucose transporter 1/hexokinase II in non-small cell lung cancer cells.

Quantitative Profiling of Single Formalin Fixed Tumour Sections: proteomics for translational research

Although re-sequencing of gene panels and mRNA expression profiling are now firmly established in clinical laboratories, in-depth proteome analysis has remained a niche technology, better suited for studying model systems rather than challenging materials such as clinical trial samples. To address this limitation, we have developed a novel and optimized platform called SP3-Clinical Tissue Proteomics (SP3-CTP) for in-depth proteome profiling of practical quantities of tumour tissues, including formalin fixed and paraffin embedded (FFPE). Using single 10 μm scrolls of clinical tumour blocks, we performed in-depth quantitative analyses of individual sections from ovarian tumours covering the high-grade serous, clear cell, and endometrioid histotypes. This examination enabled the generation of a novel high-resolution proteome map of ovarian cancer histotypes from clinical tissues. Comparison of the obtained proteome data with large-scale genome and transcriptome analyses validated the observed proteome biology for previously validated hallmarks of this disease, and also identified novel protein features. A tissue microarray analysis validated cystathionine gamma-lyase (CTH) as a novel clear cell carcinoma feature with potential clinical relevance. In addition to providing a milestone in the understanding of ovarian cancer biology, these results show that in-depth proteomic analysis of clinically annotated FFPE materials can be effectively used as a biomarker discovery tool and perhaps ultimately as a diagnostic approach.

Metabolic Modification in Gastrointestinal Cancer Stem Cells: Characteristics and Therapeutic Approaches

Currently, there is much interest in the characterization of metabolic profiling of cancer stem cells (CSCs), a small subset of tumor cells with self-renewal capacity. Indeed, ever-growing evidence indicate that metabolism and stemness are highly intertwined processes in tumor tissue. In this review, we analyze the potential metabolic targeting strategies for eradicating CSCs that could help to develop a more effective therapeutic approach for gastrointestinal cancers. Indeed, the successful elimination of a tumor requires an anticancer therapy that affects both cancer cells and CSCs. The observation that gastrointestinal CSCs possess higher inducible nitric oxide sinthase (iNOS) expression, lower reactive oxygen species (ROS) production, and a different metabolism respect to no-CSCs tumor cells has paved the way to develop drugs targeting CSC specific signaling. In particular, several studies have highlighted that metformin, aldehyde dehydrogenase 1, and iNOS inhibitors selectively suppressed CSC growth and that combinatorial therapy of them with standard chemotherapeutic drugs had a synergistic effect resulting in reduced tumor burden and delayed tumor recurrence. Thus, the possibility of combining specific CSC metabolism inhibitors with existing therapeutic approaches could have profound anticancer effects, changing the conventional treatment approaches to gastrointestinal cancers. J. Cell. Physiol. 231: 2081-2087, 2016. © 2016 Wiley Periodicals, Inc.