scholarly journals Revising PTEN in the Era of Immunotherapy: New Perspectives for an Old Story

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1525 ◽  
Author(s):  
Geny Piro ◽  
Carmine Carbone ◽  
Luisa Carbognin ◽  
Sara Pilotto ◽  
Chiara Ciccarese ◽  
...  

Immunotherapy has emerged as the new therapeutic frontier of cancer treatment, showing enormous survival benefits in multiple tumor diseases. Although undeniable success has been observed in clinical trials, not all patients respond to treatment. Different concurrent conditions can attenuate or completely abrogate the usefulness of immunotherapy due to the activation of several escape mechanisms. Indeed, the tumor microenvironment has an almost full immunosuppressive profile, creating an obstacle to therapeutic treatment. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) governs a plethora of cellular processes, including maintenance of genomic stability, cell survival/apoptosis, migration, and metabolism. The repertoire of PTEN functions has recently been expanded to include regulation of the tumor microenvironment and immune system, leading to a drastic reevaluation of the canonical paradigm of PTEN action with new potential implications for immunotherapy-based approaches. Understanding the implication of PTEN in cancer immunoediting and immune evasion is crucial to develop new cancer intervention strategies. Recent evidence has shown a double context-dependent role of PTEN in anticancer immunity. Here we summarize the current knowledge of PTEN’s role at a crossroads between tumor and immune compartments, highlighting the most recent findings that are likely to change future clinical practice.

2020 ◽  
Vol 21 (5) ◽  
pp. 1772 ◽  
Author(s):  
Lucia Barazzuol ◽  
Flavia Giamogante ◽  
Marisa Brini ◽  
Tito Calì

Endoplasmic reticulum (ER)–mitochondria contact sites are critical structures for cellular function. They are implicated in a plethora of cellular processes, including Ca2+ signalling and mitophagy, the selective degradation of damaged mitochondria. Phosphatase and tensin homolog (PTEN)-induced kinase (PINK) and Parkin proteins, whose mutations are associated with familial forms of Parkinson’s disease, are two of the best characterized mitophagy players. They accumulate at ER–mitochondria contact sites and modulate organelles crosstalk. Alterations in ER–mitochondria tethering are a common hallmark of many neurodegenerative diseases including Parkinson’s disease. Here, we summarize the current knowledge on the involvement of PINK1 and Parkin at the ER–mitochondria contact sites and their role in the modulation of Ca2+ signalling and mitophagy.


2020 ◽  
Vol 21 (15) ◽  
pp. 5337 ◽  
Author(s):  
Fabiana Conciatori ◽  
Chiara Bazzichetto ◽  
Italia Falcone ◽  
Ludovica Ciuffreda ◽  
Gianluigi Ferretti ◽  
...  

Mounting preclinical and clinical evidence indicates that rewiring the host immune system in favor of an antitumor microenvironment achieves remarkable clinical efficacy in the treatment of many hematological and solid cancer patients. Nevertheless, despite the promising development of many new and interesting therapeutic strategies, many of these still fail from a clinical point of view, probably due to the lack of prognostic and predictive biomarkers. In that respect, several data shed new light on the role of the tumor suppressor phosphatase and tensin homolog on chromosome 10 (PTEN) in affecting the composition and function of the tumor microenvironment (TME) as well as resistance/sensitivity to immunotherapy. In this review, we summarize current knowledge on PTEN functions in different TME compartments (immune and stromal cells) and how they can modulate sensitivity/resistance to different immunological manipulations and ultimately influence clinical response to cancer immunotherapy.


2015 ◽  
Vol 1 (10) ◽  
pp. e1500845 ◽  
Author(s):  
Madhav D. Sharma ◽  
Rahul Shinde ◽  
Tracy L. McGaha ◽  
Lei Huang ◽  
Rikke B. Holmgaard ◽  
...  

The tumor microenvironment is profoundly immunosuppressive. We show that multiple tumor types create intratumoral immune suppression driven by a specialized form of regulatory T cell (Treg) activation dependent on the PTEN (phosphatase and tensin homolog) lipid phosphatase. PTEN acted to stabilize Tregs in tumors, preventing them from reprogramming into inflammatory effector cells. In mice with a Treg-specific deletion of PTEN, tumors grew slowly, were inflamed, and could not create an immunosuppressive tumor microenvironment. In normal mice, exposure to apoptotic tumor cells rapidly elicited PTEN-expressing Tregs, and PTEN-deficient mice were unable to maintain tolerance to apoptotic cells. In wild-type mice with large established tumors, pharmacologic inhibition of PTEN after chemotherapy or immunotherapy profoundly reconfigured the tumor microenvironment, changing it from a suppressive to an inflammatory milieu, and tumors underwent rapid regression. Thus, the immunosuppressive milieu in tumors must be actively maintained, and tumors become susceptible to immune attack if the PTEN pathway in Tregs is disrupted.


2020 ◽  
Vol 19 ◽  
pp. 153303382092096
Author(s):  
Hongzhi Sun ◽  
Bo Zhang ◽  
Haijun Li

Pancreatic ductal adenocarcinoma has extremely high malignancy and patients with pancreatic ductal adenocarcinoma have dismal prognosis. The failure of pancreatic ductal adenocarcinoma treatment is largely due to the tumor microenvironment, which is featured by ample stromal cells and complicated extracellular matrix. Recent genomic analysis revealed that pancreatic ductal adenocarcinoma harbors frequently mutated genes including KRAS, TP53, CDKN2A, and SMAD4, which can widely alter cellular processes and behaviors. As shown by accumulating studies, these mutant genes may also change tumor microenvironment, which in turn affects pancreatic ductal adenocarcinoma progression. In this review, we summarize the role of such genetic mutations in tumor microenvironment regulation and potential mechanisms.


Author(s):  
Yarely M. Salinas-Vera ◽  
Dolores Gallardo-Rincón ◽  
Erika Ruíz-García ◽  
Macrina B. Silva-Cázares ◽  
Carmen Sol de la Peña-Cruz ◽  
...  

: Endometrial cancer represents the most frequent neoplasia from the corpus uteri, and comprises the 14th leading cause of death in women worldwide. Risk factors that contribute to the disease include early menarche, late menopause, nulliparity, and menopausal hormone use, as well as hypertension and obesity comorbidities. The clinical effectiveness of chemotherapy is variable, suggesting that novel molecular targeted therapies against specific cellular processes associated with the maintenance of cancer cell survival and therapy resistance urged to ameliorate the rates of success in endometrial cancer treatment. In the course of tumor growth, cancer cells must adapt to decreased oxygen availability in the microenvironment by upregulation of hypoxia-inducible factors, which orchestrate the activation of a transcriptional program leading to cell survival. During this adaptative process, the hypoxic cancer cells may acquire invasive and metastatic properties as well as increased cell proliferation and resistance to chemotherapy, enhanced angiogenesis, vasculogenic mimicry, and maintenance of cancer cell stemness, which contribute to more aggressive cancer phenotypes. Several studies have shown that hypoxia-inducible factor 1 alpha (HIF-1α) protein is aberrantly overexpressed in many solid tumors from breast, prostate, ovarian, bladder, colon, brain, and pancreas. Thus, it has been considered an important therapeutic target. Here, we reviewed the current knowledge of the relevant roles of cellular hypoxia mechanisms and HIF-1α functions in diverse processes associated with endometrial cancer progression. In addition, we also summarize the role of microRNAs in the posttranscriptional regulation of protein-encoding genes involved in the hypoxia response in endometrial cancer. Finally, we pointed out the need for urgent targeted therapies to impair the cellular processes activated by hypoxia in the tumor microenvironment.


Author(s):  
Annu Makker ◽  
Madhu Mati Goel ◽  
Kumari Manu ◽  
Renu Makker

Background: Balance between endometrial cell proliferation and apoptosis is crucial for successful embryo implantation. PTEN (phosphatase and tensin homolog deleted on chromosome 10), a pro-apoptotic factor, is proposed to be one of the signaling proteins through which estrogen and progesterone act to affect cellular homeostasis. Although reports in literature have suggested role of PTEN in regulating endometrial cell proliferation and apoptosis during window of implantation, its involvement in women with unexplained infertility is not clear. In the present study, we examined expression, cellular distribution and activation status of PTEN, cell proliferation, and apoptosis in midsecretory endometrium from women with unexplained infertility as compared to fertile controls.Methods: Endometrial biopsies from infertile (n=11) and fertile women (n=22) were used for immunohistochemical evaluation of PTEN, phospho-PTEN and Ki67. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling assay was performed for detection of apoptotic cells.Results: Biopsies from infertile women as compared to fertile controls demonstrated statistically significant: i) decrease in nuclear PTEN (P < 0.001), increase in nuclear phospho-PTEN (P < 0.05), increase in nuclear and cytoplasmic phospho-PTEN/PTEN ratio (P < 0.001 and P < 0.05 respectively) in endometrial stroma, ii) increase in cytoplasmic phospho-PTEN (P < 0.001) and phospho-PTEN/PTEN ratio (P < 0.05) in glandular epithelium (GE), iii) increase in Ki67 labeling in GE (P < 0.01) and stroma (P < 0.05) and, iv) decrease in (P < 0.001) apoptosis.Conclusions: Altered PTEN expression and associated modulation in cellular homeostasis during the implantation window might contribute to mechanism underlying unexplained infertility.


2021 ◽  
Vol 11 ◽  
Author(s):  
Jiakang Jin ◽  
Jinti Lin ◽  
Ankai Xu ◽  
Jianan Lou ◽  
Chao Qian ◽  
...  

Tumor microenvironment (TME) formation is a major cause of immunosuppression. The TME consists of a considerable number of macrophages and stromal cells that have been identified in multiple tumor types. CCL2 is the strongest chemoattractant involved in macrophage recruitment and a powerful initiator of inflammation. Evidence indicates that CCL2 can attract other host cells in the TME and direct their differentiation in cooperation with other cytokines. Overall, CCL2 has an unfavorable effect on prognosis in tumor patients because of the accumulation of immunosuppressive cell subtypes. However, there is also evidence demonstrating that CCL2 enhances the anti-tumor capability of specific cell types such as inflammatory monocytes and neutrophils. The inflammation state of the tumor seems to have a bi-lateral role in tumor progression. Here, we review works focusing on the interactions between cancer cells and host cells, and on the biological role of CCL2 in these processes.


2013 ◽  
Vol 49 (3) ◽  
pp. 307-313 ◽  
Author(s):  
B. O. Cetinkaya ◽  
F. Pamuk ◽  
G. C. Keles ◽  
B. Ayas ◽  
G. K. Ozfidan ◽  
...  

2018 ◽  
Vol 19 (7) ◽  
pp. 2129 ◽  
Author(s):  
Anja Weber ◽  
Helmut Klocker ◽  
Herbert Oberacher ◽  
Erich Gnaiger ◽  
Hannes Neuwirt ◽  
...  

The idea of using metabolic aberrations as targets for diagnosis or therapeutic intervention has recently gained increasing interest. In a previous study, our group discovered intriguing differences in the oxidative mitochondrial respiration capacity of benign and prostate cancer (PCa) cells. In particular, we found that PCa cells had a higher total respiratory activity than benign cells. Moreover, PCa cells showed a substantial shift towards succinate-supported mitochondrial respiration compared to benign cells, indicating a re-programming of respiratory control. This study aimed to investigate the role of succinate and its main plasma membrane transporter NaDC3 (sodium-dependent dicarboxylate transporter member 3) in PCa cells and to determine whether targeting succinate metabolism can be potentially used to inhibit PCa cell growth. Using high-resolution respirometry analysis, we observed that ROUTINE respiration in viable cells and succinate-supported respiration in permeabilized cells was higher in cells lacking the tumor suppressor phosphatase and tensin-homolog deleted on chromosome 10 (PTEN), which is frequently lost in PCa. In addition, loss of PTEN was associated with increased intracellular succinate accumulation and higher expression of NaDC3. However, siRNA-mediated knockdown of NaDC3 only moderately influenced succinate metabolism and did not affect PCa cell growth. By contrast, mersalyl acid—a broad acting inhibitor of dicarboxylic acid carriers—strongly interfered with intracellular succinate levels and resulted in reduced numbers of PCa cells. These findings suggest that blocking NaDC3 alone is insufficient to intervene with altered succinate metabolism associated with PCa. In conclusion, our data provide evidence that loss of PTEN is associated with increased succinate accumulation and enhanced succinate-supported respiration, which cannot be overcome by inhibiting the succinate transporter NaDC3 alone.


2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Stéphane Rodriguez ◽  
Uyen Huynh-Do

During the past 20 years, the phosphatase and tensin homolog PTEN has been shown to be involved in major physiological processes, and its mutation or loss is often associated with tumor formation. In addition PTEN regulates angiogenesis not only through its antagonizing effect on the PI3 kinase pathway mainly, but also through some phosphatase-independent functions. In this paper we delineate the role of this powerful tumor suppressor in tumor angiogenesis and dissect the underlying molecular mechanisms. Furthermore, it appears that, in a number of cancers, the PTEN status determines the response to chemotherapy, highlighting the need to monitor PTEN expression and to develop PTEN-targeted therapies.


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