Metastasis: recent discoveries and novel treatment strategies

Oncological transformation in vitro of hepatic progenitor cell lines isolated from adult mice

Colorectal cancer cells can transfer the oncogene KRAS to distant cells, predisposing them to malignant transformation (Genometastasis Theory). This process could contribute to liver metastasis; besides, hepatic progenitor cells (HPCs) have been found to be involved in liver malignant neoplasms. The objective of this study is to determine if mouse HPCs—Oval cells (OCs)—are susceptible to incorporate Kras GAT (G12D) mutation from mouse colorectal cancer cell line CT26.WT and if OCs with the incorporated mutation behave like malignant cells. To achieve this, three lines of OCs in different conditions were exposed to CT26.WT cells through transwell co-culture for a week. The presence of Kras^G12D and capacity to form tumors were analyzed in treated samples by droplet digital PCR and colony-forming assays, respectively. The results showed that the Kras^G12D mutation was detected in hepatic culture conditions of undifferentiated OCs and these cells were capable of forming tumors in vitro. Therefore, OCs are susceptible to malignant transformation by horizontal transfer of DNA with Kras^G12D mutation in an undifferentiated condition associated with the liver microenvironment. This study contributes to a new step in the understanding of the colorectal metastatic process.

Comparison of Sample Preparation Methods for Rare Cell Isolation in Microfluidic Devices

The analysis of circulating tumor cells (CTCs) is important for cancer diagnosis and prognosis. Microfluidics has been employed for CTC analysis due to their scaling advantages and high performance. However, pre-analytical methods for CTC sample preparation are often combined with microfluidic platforms because a large sample volume is required to detect extremely rare CTCs. Among pre-analytical methods, Ficoll-Paque™, OncoQuick™, and RosetteSep™ are commonly used to separate blood cells of interest. To compare their performance, we spiked L3.6pl pancreatic cancer cells into healthy blood samples, then employed each technique to prepare blood samples, followed by using a microfluidic platform to capture and detect L3.6pl cells. We found these three methods have similar performance, though the slight edge of RosetteSep™ over Ficoll-Paque™ is statistically significant. We also studied the effects of the tumor cell concentrations on the performance of the frequently used Ficoll-Paque™ method. Furthermore, we examined the repeatability and variability of each pre-analytical technique and the microfluidics-enabled detection. This study will provide researchers and clinicians with comparative data that can influence the choice of sample preparation method, help estimate CTC loss in each pre-analytical method, and correlate the results of clinical studies that employ different techniques.

Significance of Lymph Node Metastasis in the Treatment of Gastric Cancer and Current Challenges in Determining the Extent of Metastasis

The stomach exhibits abundant lymphatic flow, and metastasis to lymph nodes is common. In the case of gastric cancer, there is a regularity to the spread of lymph node metastasis, and it does not easily metastasize outside the regional nodes. Furthermore, when its extent is limited, nodal metastasis of gastric cancer can be cured by appropriate lymph node dissection. Therefore, identifying and determining the extent of lymph node metastasis is important for ensuring accurate diagnosis and appropriate surgical treatment in patients with gastric cancer. However, precise detection of lymph node metastasis remains difficult. Most nodal metastases in gastric cancer are microscopic metastases, which often occur in small-sized lymph nodes, and are thus difficult to diagnose both preoperatively and intraoperatively. Preoperative nodal diagnoses are mainly made using computed tomography, although the specificity of this method is low because it is mainly based on the size of the lymph node. Furthermore, peripheral nodal metastases cannot be palpated intraoperatively, nodal harvesting of resected specimens remains difficult, and the number of lymph nodes detected vary greatly depending on the skill of the technician. Based on these findings, gastrectomy with prophylactic lymph node dissection is considered the standard surgical procedure for gastric cancer. In contrast, several groups have examined the value of sentinel node biopsy for accurately evaluating nodal metastasis in patients with early gastric cancer, reporting high sensitivity and accuracy. Sentinel node biopsy is also important for individualizing and optimizing the extent of uniform prophylactic lymph node dissection and determining whether patients are indicated for function-preserving curative gastrectomy, which is superior in preventing post-gastrectomy symptoms and maintaining dietary habits. Notably, advancements in surgical treatment for early gastric cancer are expected to result in individualized surgical strategies with sentinel node biopsy. Chemotherapy for advanced gastric cancer has also progressed, and conversion gastrectomy can now be performed after downstaging, even in cases previously regarded as inoperable. In this review, we discuss the importance of determining lymph node metastasis in the treatment of gastric cancer, the associated difficulties, and the need to investigate strategies that can improve the diagnosis of lymph node metastasis.

Cytokeratin 19 expression in intrathoracic neoplasms: First study utilizing cellblocks, evaluating the role of a rarely used cytokeratin for lung cancers

BACKGROUND

Cytokeratin 19 (CK19) is low-molecular weight CK with widespread expression in various malignancies including those of lung, colon, and breast. Occasional studies have also indicated prognostic utility of CK19 in nonsmall cell lung carcinomas, with better prognosis among squamous cell carcinoma cases with strong CK19 immunostaining. The aim of this study was to evaluate the expression and potential roles of CK19 immunostaining in cases of carcinoma lung as well as other metastatic intrathoracic neoplasms.

METHODS

This was a prospective single-center study of 2 years duration, during which 233 cases of endobronchial ultrasound guided aspiration of the intrathoracic lesions were examined. After excluding the cases without cellblock, with inadequate samples, with benign diagnosis, and excluding the lymphoma cases, finally 31 neoplastic cases were evaluated for expression of cytokeratin 19.

RESULTS

Diffuse cytoplasmic staining for CK19 was noted in nonsmall cell lung carcinomas (18/19 cases), while the expression in small cell carcinomas was low (2/5 cases). CK19 was also positive in mediastinal lymph node metastasis from a case each of papillary thyroid carcinoma, prostatic adenocarcinoma and infiltrating ductal carcinoma breast (1/2 cases). It showed focal faint staining in a case of mediastinal mesenchymal neoplasm and was negative in both the cases of primitive neuroectodermal tumor.

CONCLUSIONS

CK19 is a highly sensitive but nonspecific marker for nonsmall cell lung cancers. However, owing to diffuse staining pattern in most of these cases, role of its staining intensity as a predictor of prognosis could not be evaluated.

RNA N6-methyladenosine reader IGF2BP2 promotes lymphatic metastasis and epithelial-mesenchymal transition of head and neck squamous carcinoma cells via stabilizing slug mRNA in an m6A-dependent manner

Background

Lymph node metastasis is the main cause of poor prognosis of head and neck squamous carcinoma (HNSCC) patients. N6-methyladenosine (m6A) RNA modification is an emerging epigenetic regulatory mechanism for gene expression, and as a novel m6A reader protein, IGF2BP2 has been implicated in tumor progression and metastasis. However, not much is currently known about the functional roles of IGF2BP2 in HNSCC, and whether IGF2BP2 regulates lymphatic metastasis through m6A modification in HNSCC remains to be determined.

Methods

The expression and overall survival (OS) probability of m6A-related regulators in HNSCC were analyzed with The Cancer Genome Atlas (TCGA) dataset and GEPIA website tool, respectively. The expression levels of IGF2BP2 were measured in HNSCC tissues and normal adjacent tissues. To study the effects of IGF2BP2 on HNSCC cell metastasis in vitro and in vivo, gain- and loss- of function methods were employed. RIP, MeRIP, luciferase reporter and mRNA stability assays were performed to explore the epigenetic mechanism of IGF2BP2 in HNSCC.

Results

We investigated 20 m6A-related regulators in HNSCC and discovered that only the overexpression of IGF2BP2 was associated with a poor OS probability and an independent prognostic factor for HNSCC patients. Additionally, we demonstrated that IGF2BP2 was overexpressed in HNSCC tissues, and significantly correlated to lymphatic metastasis and poor prognosis. Functional studies have shown that IGF2BP2 promotes both HNSCC cell migration as well as invasion via the epithelial-mesenchymal transition (EMT) process in vitro, and IGF2BP2 knockdown significantly inhibited lymphatic metastasis and lymphangiogenesis in vivo. Mechanistic investigations revealed that Slug, a key EMT-related transcriptional factor, is the direct target of IGF2BP2, and essential for IGF2BP2-regulated EMT and metastasis in HNSCC. Furthermore, we demonstrated that IGF2BP2 recognizes and binds the m6A site in the coding sequence (CDS) region of Slug and promotes its mRNA stability.

Conclusions

Collectively, our study uncovers the oncogenic role and potential mechanism of IGF2BP2, which serves as a m6A reader, in controlling lymphatic metastasis and EMT in HNSCC, suggesting that IGF2BP2 may act as a therapeutic target and prognostic biomarker for HNSCC patients with metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-02212-1.

TJP1, a Membrane-Expressed Protein, is a Potential Therapeutic and Prognostic Target for Lung Cancer

Objective: Lung cancer is a malignant tumor with the highest mortality rate in the world. It is necessary to develop effective biomarkers for diagnosis or prognostic treatment to improve the survival rate of patients. In this prospective study, we identified a membrane-expressed protein Tight Junction Protein 1 (TJP1), which is an ideal therapeutic target for lung cancer, and demonstrated its role in invasion, migration, and proliferation of lung cancer. Methods: High-throughput monoclonal antibody microarrays were used to screen for differential expression of monoclonal antibodies (mAbs) in lung cancer and normal lung tissue. Differentially expressed antibodies were used to immunoprecipitate their cellular targets to be identified by mass spectrometry. The identified target TJP1 was knocked down to observe the effect of reduced gene expression on lung cancer cell function. Immunohistochemistry on human tumor tissues and The Cancer Genome Atlas (TCGA) database was used to explore the relationship between TJP1 expression in multiple cancer types and patient prognosis. Results: The antibody CL007473 was overexpressed in tumor tissue and its target protein was identified by mass spectrometry and immunofluorescence as TJP1, a membrane-expressed protein. Knockdown of TJP1 in lung cancer cell lines showed that reduced expression of TJP1 could inhibit the invasion and migration of lung cancer cells and inhibit the proliferation of cancer cells, suggesting that membrane-expressed protein TJP1 may be used as a therapeutic target for lung cancer. TCGA database analysis showed that TJP1 was highly expressed in pancreatic cancer (PAAD) tissues compared with normal tissues, and low expression was more beneficial to the prognosis and survival of PAAD patients. Conclusion: Membrane-expressed protein TJP1 may be a good therapeutic and prognostic target for lung cancer and has the potential to be a prognostic biomarker in pancreatic cancer.

The expression and function of miR-622 in a variety of tumors

Cancer is a heavy burden worldwide, with high morbidity and mortality rates. Cancer treatments currently involve surgical and nonsurgical approaches. Molecular targeted therapy is the latest breakthrough. miRNAs are small noncoding RNAs found in plants and animals that play a role in cancer and various diseases through influencing numerous biological processes, such as cell proliferation, apoptosis, the immune response, and drug resistance. One miRNA, miR-622, has been shown to regulate various pathways to influence disease processes. Abnormal miR-622 expression can promote or inhibit liver, colorectal, and breast cancers and other tumors, such as glioma. Herein, we reviewed the expression levels and clinical effects of miR-622 in various tumors and summarized its mechanisms and related molecules.

In Situ Nanotransformable Hydrogel for Chemo-Photothermal Therapy of Localized Tumors and Targeted Therapy of Highly Metastatic Tumors

Metastasis is one of the predisposing factors for cancer-related mortalities worldwide. Patients with advanced cancers (stage IV) receive palliative care with minimal possibility of achieving complete remission. Antibody-based therapeutic modalities are capable of targeting tumors that are confined to a particular location but are ineffective in targeting distant secondary tumors. In the current study, we have developed a smart nano-transforming hydrogel (NTG) that transforms in situ to polymeric nanoparticles (PA NPs) of 100-150 nm when injected subcutaneously. These nanoparticles targeted the primary and secondary metastatic tumors for up to ∼5 and ∼3 days, respectively. The in situ-formed PA NPs also demonstrated a pH-responsive drug release resulting in about ∼80% release within 100 h at 5.8 pH. When tested in vivo, substantial inhibition of lung metastases was observed compared to chemotherapy, thus demonstrating the efficiency of nanotransforming hydrogels in targeting and inhibiting primary and secondary metastatic tumors.

Extracellular Vesicles in Osteosarcoma: Antagonists or Therapeutic Agents?

Osteosarcoma (OS) is a skeletal tumor affecting mainly children and adolescents. The presence of distance metastasis is frequent and it is localized preferentially to the lung, representing the main reason for death among patients. The therapeutic approaches are based on surgery and chemotherapeutics. However, the drug resistance and the side effects associated with the chemotherapy require the identification of new therapeutic approaches. The understanding of the complex biological scenario of the osteosarcoma will open the way for the identification of new targets for its treatment. Recently, a great interest of scientific community is for extracellular vesicles (EVs), that are released in the tumor microenvironment and are important regulators of tumor proliferation and the metastatic process. At the same time, circulating extracellular vesicles can be exploited as diagnostic and prognostic biomarkers, and they can be loaded with drugs as a new therapeutic approach for osteosarcoma patients. Thus, the characterization of OS-related EVs could represent a way to convert these vesicles from antagonists for human health into therapeutic and/or diagnostic agents.

Association Between Different Domains of Physical Activity and Body Adiposity Indicators in Breast Cancer Survivors

BACKGROUND

To analyze the relationship between different physical activity (PA) domains and adiposity indicators in breast cancer survivors.

METHODS

This is a cross-sectional study, composed of 115 breast cancer (BC) survivors. Measurements of weight, height, waist circumference (WC), and hip circumference were objectively collected, as well as the analysis of body fat percentage through bioelectrical impedance analysis. The PA level was assessed by the Baecke questionnaire including domains related to occupational activity, leisure-time activity, and transportation, while the time spent in sedentary behavior was assessed through self-reported screen-time. Socioeconomic status was assessed through the Brazilian criteria for economic classification and considered as a covariate.

RESULTS

BC survivors with higher PA levels in leisure-time activity/sport presented reductions in body fat percentage (β = 1.13%; CI = -2.06; -0.21), BMI (β = 0.80 kg/m²; CI = -1.50; -0.11), WC (β = 1.89 cm; CI = -3.54; -0.23), and waist-to-height ratio (β = 0.13 cm; CI = -0.23; -0.02). Similar values were observed in PA during transportation and in total. There was no correlation between PA at work and adiposity indicators.

CONCLUSION

Different PA domains were inversely related to body adiposity in BC survivors.

Liquid biopsy = Individualized cancer management: Diagnosis, monitoring treatment and checking recurrence and metastasis

Traditional cancer-screening techniques such as imaging and protein biomarkers are not sufficient for early detection. Various forms of endoscopy and tumour biopsy are the current standard methods in diagnosing Head Neck Cancers. Liquid biopsy has been increasingly considered as an option for molecular characterization and detection of cancer as it can provide real-time information about cancer in a minimally invasive manner. Circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and exosomal miRNAs are emerging biomarkers that can be applied to cancer detection, treatment planning, and response monitoring. A 'liquid biopsy' presents an option where the disease can be tracked in a less-invasive, simple manner, allowing for serial sampling informing of the tumour heterogeneity, response to treatment and minimal residual disease.

An ultrasound-driven immune-boosting molecular machine for systemic tumor suppression

Exploring facile and effective therapeutic modalities for synergistically controlling primary tumor and metastasis remains a pressing clinical need. Sonodynamic therapy (SDT) offers the possibility of noninvasively eradicating local solid tumors, but lacks antimetastatic activity because of its limited ability in generating systemic antitumor effect. Here, we exploited a previously unidentified ultrasound-driven “molecular machine,” DYSP-C34 (C34 for short), with multiple attractive features, emerging from preferential tumor accumulation, potent ultrasound-triggered cytotoxicity, and intrinsic immune-boosting capacity. Driven by the ultrasound, C34 functioned not only as a tumor cell killing reagent but also as an immune booster that could potentiate robust adaptive antitumor immunity by directly stimulating dendritic cells, resulting in the eradication of the primary solid tumor along with the inhibition of metastasis. This molecular machine, C34, rendered great promise to achieve systemic treatment against cancer via unimolecule-mediated SDT.

Human induced pluripotent stem cell-derived platelets loaded with lapatinib effectively target HER2+ breast cancer metastasis to the brain

Prognosis of patients with HER2+ breast-to-brain-metastasis (BBM) is dismal even after current standard-of-care treatments, including surgical resection, whole-brain radiation, and systemic chemotherapy. Radiation and systemic chemotherapies can also induce cytotoxicity, leading to significant side effects. Studies indicate that donor-derived platelets can serve as immune-compatible drug carriers that interact with and deliver drugs to cancer cells with fewer side effects, making them a promising therapeutic option with enhanced antitumor activity. Moreover, human induced pluripotent stem cells (hiPSCs) provide a potentially renewable source of clinical-grade transfusable platelets that can be drug-loaded to complement the supply of donor-derived platelets. Here, we describe methods for ex vivo generation of megakaryocytes (MKs) and functional platelets from hiPSCs (hiPSC-platelets) in a scalable fashion. We then loaded hiPSC-platelets with lapatinib and infused them into BBM tumor-bearing NOD/SCID mouse models. Such treatment significantly increased intracellular lapatinib accumulation in BBMs in vivo, potentially via tumor cell-induced activation/aggregation. Lapatinib-loaded hiPSC-platelets exhibited normal morphology and function and released lapatinib pH-dependently. Importantly, lapatinib delivery to BBM cells via hiPSC-platelets inhibited tumor growth and prolonged survival of tumor-bearing mice. Overall, use of lapatinib-loaded hiPSC-platelets effectively reduced adverse effects of free lapatinib and enhanced its therapeutic efficacy, suggesting that they represent a novel means to deliver chemotherapeutic drugs as treatment for BBM.

Machine learning and deep learning methods that use omics data for metastasis prediction

Knowing metastasis is the primary cause of cancer-related deaths, incentivized research directed towards unraveling the complex cellular processes that drive the metastasis. Advancement in technology and specifically the advent of high-throughput sequencing provides knowledge of such processes. This knowledge led to the development of therapeutic and clinical applications, and is now being used to predict the onset of metastasis to improve diagnostics and disease therapies. In this regard, predicting metastasis onset has also been explored using artificial intelligence approaches that are machine learning, and more recently, deep learning-based. This review summarizes the different machine learning and deep learning-based metastasis prediction methods developed to date. We also detail the different types of molecular data used to build the models and the critical signatures derived from the different methods. We further highlight the challenges associated with using machine learning and deep learning methods, and provide suggestions to improve the predictive performance of such methods.

Enhancement of Immune Checkpoint Inhibitor-Mediated Anti-Cancer Immunity by Intranasal Treatment of Ecklonia cava Fucoidan against Metastatic Lung Cancer

Although fucoidan, a well-studied seaweed-extracted polysaccharide, has shown immune stimulatory effects that elicit anticancer immunity, mucosal adjuvant effects via intranasal administration have not been studied. In this study, the effect of Ecklonia cava-extracted fucoidan (ECF) on the induction of anti-cancer immunity in the lung was examined by intranasal administration. In C57BL/6 and BALB/c mice, intranasal administration of ECF promoted the activation of dendritic cells (DCs), natural killer (NK) cells, and T cells in the mediastinal lymph node (mLN). The ECF-induced NK and T cell activation was mediated by DCs. In addition, intranasal injection with ECF enhanced the anti-PD-L1 antibody-mediated anti-cancer activities against B16 melanoma and CT-26 carcinoma tumor growth in the lungs, which were required cytotoxic T lymphocytes and NK cells. Thus, these data demonstrated that ECF functioned as a mucosal adjuvant that enhanced the immunotherapeutic effect of immune checkpoint inhibitors against metastatic lung cancer.

Hydrostatic pressure stabilizes HIF‑1α expression in cancer cells to protect against oxidative damage during metastasis

The tissue microenvironment is known to play a pivotal role in cancer metastasis. Interstitial fluid hydrostatic pressure generally increases along with the rapid growth of malignant tumors. The aim of the present study was to investigate the role and relevant mechanism of elevated hydrostatic pressure in promoting the metastasis of cancer cells. Using a commercial device, Lewis lung cancer (LLC) cells were exposed to 50 mmHg hydrostatic pressure (HP) for 24 h. The survival time and morphology of the cells did not notably change; however, the results from a PCR array revealed the upregulation of numerous metastasis‑promoting genes (Hgf, Cdh11 and Ephb2) and the downregulation of metastasis suppressing genes (Kiss1, Syk and Htatip2). In addition, compared with that in the control, the cells which had undergone exposure to 50 mmHg HP showed significantly higher protein expression level of HIF‑1α and the antioxidant enzymes, SOD1 and SOD2, as well as improved tolerance to oxidative stress (P<0.05 vs. control). Following an intravenous injection of the LLC cells into healthy mice, to induce lung metastasis, it was found that the exposure of the LLC cells to 50 mmHg HP for 24 h, prior to injection into the mice, resulted in higher cell survival/retention in the lungs 24 h later and also resulted in more metastatic tumor lesions 4 weeks later (P<0.05 vs. control). Further investigation is required to confirm the molecular mechanism; however, the results from the present study suggested that elevated interstitial fluid HP in malignant tumors may promote the metastasis of cancer cells by stabilizing HIF‑1α expression to defend against oxidative damage.

Development of a Sandwich Chemiluminescence Immunoassay for the Detection of Intact Procollagen Type I N Propeptide with Magnetic Nanosphere Carrier Technology

The metabolic product of type I collagen synthesis, intact procollagen type I N propeptide (intact PINP), is a potential marker of bone formation and osteoporosis, which is not affected by kidney function. We sought to establish a chemiluminescent immunoassay method for the detection of serum intact PINP with previously prepared paired monoclonal antibodies and to evaluate the diagnostic value of the assay in osteoporosis. Using the capture molecule and monoclonal antibody as detection molecule, a diagnostic reagent was developed to detect intact PINP in serum with magnetic nanosphere carriers by the chemiluminescence method, and its analytical performance in the laboratory was evaluated. Serum intact PINP was measured in 142 healthy people and 115 osteoporosis patients. Results were matched with results of a similar test kit, Roche total PINP Elecsys Chemiluminescent Immunoassay Assay. Compared with the performance of the Roche PINP assay product, our method had higher sensitivity (0.02 ng/mL), wider linear range (0.02-1500 ng/mL), and anti-interference. Serum intact PINP values in osteoporosis patients were significantly higher than in healthy subjects (p < 0.001). Our method had good consistency compared with the Roche PINP assay (r = 0.9794). This chemiluminescence method for detecting serum intact PINP (CLIA-intact PINP) with magnetic nanosphere carrier technology meets the requirements of a clinical testing reagent and is expected to have clinical application after further evaluation and can compete with expensive imported kits on the market.

A two-pronged photodynamic nanodrug to prevent metastasis of basal-like breast cancer

A two-pronged concept combining photodynamic therapy (PDT) and epithelial-mesenchymal transition (EMT) blockade in a minimalist nanoplatform was proposed to combat basal-like breast cancer (BLBC) metastasis. Based on PDT-mediated tumor killing and epalrestat (Epa)-mediated EMT blockade, as-prepared Ce6/Epa nanoparticles prevented BLBC metastasis effectively in vivo, providing a very promising two-pronged strategy against BLBC metastasis.

Clinical verification of vimentin/EpCAM immunolipid magnetic sorting system in monitoring CTCs in arterial and venous blood of advanced tumor

BACKGROUND

Circulating tumor cells (CTCs) are the dominant factor leading to tumor metastasis. This study aims to investigate the effect of disparate sources of CTCs on the treatment and prognosis of patients with advanced tumors by analyzing the number and gene mutations change of CTCs in arterial and venous blood in patients with advanced tumors.

RESULTS

A CTCs sorting system was constructed based on Vimentin-immunolipid magnetic balls (Vi-IMB) and EpCAM immunolipid magnetic balls (Ep-IMB). Results showed that the prepared Ep-IMB and Vi-IMB had lower cytotoxicity, better specificity and sensitivity. The number of arterial CTCs was higher than that of venous CTCs, with a statistically significant difference (P < 0.05). Moreover, the prognosis of the low positive group of total CTCs in arterial blood and venous blood was higher than that of the high positive group, with a statistical significance (P < 0.05). The genetic testing results showed that the targeted drug gene mutations in tissues, arterial CTCs and venous CTCs showed a complementary trend, indicating that there was heterogeneity among different tumor samples.

CONCLUSIONS

CTCs in blood can be efficiently captured by the CTCs sorting system based on Vi-LMB/Ep-LMB, and CTCs detection in arterial blood can be utilized to more accurately evaluate the prognosis and predict postoperative progress. It is further confirmed that tumor samples from disparate sources are heterogeneous, providing a reference basis for gene mutation detection before clinical targeted drug treatment, and the detection of CTCs in arterial blood has more potential clinical application value.

TRIAL REGISTRATION

The Ethics Committee of Putuo Hospital, PTEC-A-2019-18-1. Registered 24 September 2019.

Effectiveness of Transarterial Chemoembolization-First Treatment for Advanced Hepatocellular Carcinoma: A Propensity Score Matching Analysis

Background

Still in real-world practice, advanced hepatocellular carcinoma (HCC) patients are treated with transarterial chemoembolization (TACE). This study compared the therapeutic effectiveness of initial TACE treatment and initial sorafenib treatment in advanced HCC patients.

Patient and Methods

Advanced HCC patients initially treated with sorafenib or TACE were included in this study. Treatment crossover due to an unfavorable response to initial treatment was allowed. Propensity score (PS) matching was applied for balancing baseline characteristics. The primary outcome was overall survival (OS) and the secondary outcomes included tumor response.

Results

A total of 554 patients were included in this study: 85 were initially treated with sorafenib (the sorafenib-first group) and 469 with TACE (the TACE-first group). In the entire cohort, the TACE-first group was associated with lower risk of death [adjusted hazard ratio (HR)=0.75, P=0.04]. In the PS-matched cohort (85 patients per group), the TACE-first group showed longer OS than the sorafenib-first group in both univariable (HR=0.68, P=0.02) and multivariable analyses (adjusted HR=0.58, P=0.002). Specifically, within both the entire and the PS-matched cohorts, the TACE-first group showed longer OS in subgroups with major portal vein tumor thrombosis (HR=0.72, P=0.048; HR=0.52, P=0.003) or infiltrative HCC (HR=0.42, P<0.001; HR=0.30, P=0.004, respectively). The objective response rate was higher in the TACE-first group (29.3% vs 14.7%, P=0.03) within the PS-matched cohort.

Conclusion

For advanced HCC, initial TACE leads to longer OS with a more favorable tumor response than initial sorafenib treatment. Intrahepatic tumor control with initial locoregional therapy may be a potent strategy for advanced HCC.

Overexpression of PTPRN Promotes Metastasis of Lung Adenocarcinoma and Suppresses NK Cell Cytotoxicity

Background

Lung adenocarcinoma (LUAD) is the most common diagnostic histologic subtype of non-small cell lung cancer, but the role of receptor-type tyrosine-protein phosphatase-like N (PTPRN) in LUAD has not been studied.

Methods

We conducted a bioinformatic analysis to identify the expression of PTPRN on LUAD data from the Cancer Genome Atlas (TCGA) and the relationship between PTPRN and overall survival of LUAD patients. The effects of PTPRN on the migration ability of LUAD cells and the underlying mechanisms were investigated by in vitro and in vivo assays (i.e., wound healing assay, transwell assay, western blotting, xenograft model, and immunohistochemistry). Gene-set enrichment analysis and computational resource were used to analyze the correlation between PTPRN and different tumor-infiltrating immune cells (TIICs). Lactate dehydrogenase assay and Enzyme-linked immunosorbent assay were conducted to examine natural killer (NK) cell cytotoxicity.

Results

In our study, we found that PTPRN was up-regulated in LUAD and related to metastasis of LUAD patients. Besides, PTPRN was correlated with poor prognosis in the TCGA-LUAD dataset. PTPRN overexpression promoted LUAD cell migration and the expression of EMT markers by influencing MEK/ERK and PI3K/AKT signaling. Moreover, PTPRN expression was significantly associated with TIICs, especially NK cells. A549 and H1299 cells overexpressed PTPRN inhibited NK cell cytotoxicity.

Conclusion

Taken together, these findings demonstrated that PTPRN might be a potential and novel therapeutic target modulating antitumor immune response in treatment of LUAD.

Atovaquone Suppresses the Growth of Metastatic Triple-Negative Breast Tumors in Lungs and Brain by Inhibiting Integrin/FAK Signaling Axis

Triple-negative breast cancer (TNBC) is considered to be the most aggressive and malignant neoplasm and is highly metastatic in nature. In the current study, we investigated the anti-metastatic potential of atovaquone, a protozoal drug prescribed for Pneumocystis pneumonia. We showed that atovaquone induced apoptosis and reduced the survival of several aggressive metastatic TNBC cell lines including metastatic patient-derived cells by reducing the expression of integrin α6, integrin β4, FAK, Src, and Vimentin. In order to study the efficacy of atovaquone in suppressing metastasized breast tumor cells in brain and lungs, we performed three in vivo experiments. We demonstrated that oral administration of 50 mg/kg of atovaquone suppressed MDA-MB-231 breast tumor growth by 90% in lungs in an intravenous metastatic tumor model. Anti-metastatic effect of atovaquone was further determined by intracardiac injection of 4T1-luc breast tumor cells into the left ventricle of mouse heart. Our results showed that atovaquone treatment suppressed the growth of metastatic tumors in lungs, liver and brain by 70%, 50% and 30% respectively. In an intracranial model, the growth of HCC1806-luc brain tumors in atovaquone treated mice was about 55% less than that of control. Taken together, our results indicate the anti-metastatic effects of atovaquone in vitro and in vivo in various breast tumor metastasis models.

Systemic metastasis-targeted nanotherapeutic reinforces tumor surgical resection and chemotherapy

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Metastasis consists of three steps: (i) tumor cells extravasate from the primary sites into the circulation system via epithelial-mesenchymal transition (EMT), (ii) the circulating tumor cells (CTCs) form “micro-thrombi” with platelets to evade the immune surveillance in circulation, and (iii) the CTCs colonize in the pre-metastatic niche. Here, we design a systemic metastasis-targeted nanotherapeutic (H@CaPP) composed of an anti-inflammatory agent, piceatannol, and an anti-thrombotic agent, low molecular weight heparin, to hinder the multiple steps of tumor metastasis. H@CaPP is found efficiently impeded EMT, inhibited the formation of “micro-thrombi”, and prevented the development of pre-metastatic niche. When combined with surgical resection or chemotherapy, H@CaPP efficiently inhibits tumor metastasis and prolonged overall survival of tumor-bearing mice. Collectively, we provide a simple and effective systemic metastasis-targeted nanotherapeutic for combating tumor metastasis.

Failure of conventional clinical therapies such as tumor resection and chemotherapy are mainly due to the ineffective control of tumor metastasis. Here, the authors show that a systemic metastasis-targeted nanotherapeutic may offer a powerful adjunct therapy for suppressing tumor metastasis.

Downregulation of SUMO2 inhibits hepatocellular carcinoma cell proliferation, migration and invasion

This study aimed to evaluate the prognostic value and biological function of small ubiquitin‐like modifier 2 (SUMO2) in hepatocellular carcinoma (HCC). SUMO2 expression in HCC tissues was markedly higher than that in normal liver tissues, and patients with high SUMO2 expression had significantly shorter median overall survival than those with low SUMO2 expression. Furthermore, SUMO2 expression was closely correlated with lymph node metastasis and vascular invasion and was a predictor of poor prognosis. The knockdown of SUMO2 in two HCC cell lines (SMMC‐7721 and Bel‐7404) dramatically suppressed their proliferation, migration and invasion. Western blot analysis showed that the downregulation of SUMO2 significantly reduced the expression of Ki‐67, matrix metalloproteinase‐9 (MMP‐9) and vascular endothelial growth factor (VEGF) in SMMC‐7721 and Bel‐7404 cells. Similarly, quantitative reverse transcription–PCR revealed consistently decreased expression of MMP‐9 and VEGF. Our data suggest that SUMO2 promotes proliferation, migration and invasion of HCC cells via mechanisms involving MMP‐9 and VEGF. Therefore, SUMO2 may be a prognostic factor and a promising therapeutic target for patients with HCC.

Cross talk between autophagy and oncogenic signaling pathways and implications for cancer therapy

Autophagy is a highly conserved metabolic process involved in the degradation of intracellular components including proteins and organelles. Consequently, it plays a critical role in recycling metabolic energy for the maintenance of cellular homeostasis in response to various stressors. In cancer, autophagy either suppresses or promotes cancer progression depending on the stage and cancer type. Epithelial-mesenchymal transition (EMT) and cancer metastasis are directly mediated by oncogenic signal proteins including SNAI1, SLUG, ZEB1/2, and NOTCH1, which are functionally correlated with autophagy. In this report, we discuss the crosstalk between oncogenic signaling pathways and autophagy followed by possible strategies for cancer treatment via regulation of autophagy. Although autophagy affects EMT and cancer metastasis, the overall signaling pathways connecting cancer progression and autophagy are still illusive. In general, autophagy plays a critical role in cancer cell survival by providing a minimum level of energy via self-digestion. Thus, cancer cells face nutrient limitations and challenges under stress during EMT and metastasis. Conversely, autophagy acts as a potential cancer suppressor by degrading oncogenic proteins, which are essential for cancer progression, and by removing damaged components such as mitochondria to enhance genomic stability. Therefore, autophagy activators or inhibitors represent possible cancer therapeutics. We further discuss the regulation of autophagy-dependent degradation of oncogenic proteins and its functional correlation with oncogenic signaling pathways, with potential applications in cancer therapy.

ROS-induced cell cycle arrest as a mechanism of resistance in polyaneuploid cancer cells (PACCs)

Cancer is responsible for the deaths of millions of people worldwide each year. Once metastasized, the disease is incurable and shows resistance to all anti-cancer therapies. The already-elevated level of reactive oxygen species (ROS) in cancer cells is further increased by therapies. The oxidative stress activates the DNA damage response (DDR) and the stressed cancer cell moves towards cell cycle arrest. Once arrested, the majority of cancer cells will undergo programmed cell death in the form of apoptosis. If the cancer cell is able to exit the cell cycle prior to cell division and enter a protected G0 state, it is able to withstand and survive therapy as a polyaneuploid cancer cell (PACC) and eventually seed resistant tumor growth.

TCEB3 is Regulated by Circ-0000212/miR-140-3p Axis to Promote the Progression of Cervical Cancer

BACKGROUND

Cervical cancer is a common female malignancy, which accounts for a large proportion of cancer-related mortality in the world. Therefore, exploring the mechanisms of cervical cancer progression and seeking new therapeutic targets are extraordinarily needful. The aim of this study was to explore the role of TCEB3 in cervical cancer progression.

METHODS

TCEB3 expression was detected in cervical cancer tissue and adjacent normal tissues using qRT-PCR and immunohistochemistry analysis. TCEB3 expression was measured in cells using Western blot and qRT-PCR assay. Flow cytometer, CCK-8, colony formation and transwell assays were used to detect cell apoptosis, viability, colony-forming ability and invasion of cervical cancer cells. The expression of Ki-67, MMP-2, and MMP-9 was detected using Western blot. Bioinformatics analysis was used to predict circRNA-miRNA and miRNA-mRNA interactions. RIP and luciferase reporter assay were used to determine the interaction relationship.

RESULTS

TCEB3 expression was up-regulated in both cervical cancer tissues and cells. Silencing of TCEB3 inhibited cell proliferation and invasion and promoted apoptosis of cervical cancer cells. Additionally, silencing of TCEB3 reduced the protein expression of Ki-67, MMP-2, and MMP-9 of cervical cancer cells. Mechanistically, we identified that TCEB3 was directly targeted gene of miR-140-3p, and circ-0000212 acted as a sponge of miR-140-3p. Moreover, TCEB3 was regulated by circ-0000212/miR-140-3p axis and played a tumor promotive role in cervical cancer.

CONCLUSION

Silencing of TCEB3 attenuated cell proliferation and invasion and promoted apoptosis of cervical cancer cells, and this effect was regulated by circ-0000212/miR-140-3p axis. Our findings may provide a novel promising target for cervical cancer treatment.

Usefulness of monitoring circulating tumor cells as a therapeutic biomarker in melanoma with BRAF mutation

BACKGROUND

While molecularly targeted therapies and immune checkpoint inhibitors have improved the prognosis of advanced melanoma, biomarkers are required to monitor drug responses. Circulating tumor cells (CTCs) are released from primary and/or metastatic tumors into the peripheral blood. We examined whether CTCs have potential as biomarkers by checking the number of CTCs, as well as the BRAF genotype of individual CTCs, in melanoma patients undergoing BRAF/MEK inhibitor treatment.

METHODS

CTCs were isolated from peripheral blood using a high-density dielectrophoretic microwell array, followed by labeling with melanoma-specific markers (MART-1 and/or gp100) and a leukocyte marker (CD45). The numbers of CTCs were analyzed in fifteen patients with stage 0-III melanoma. Furthermore, changes in CTC numbers were assessed in five patients with stage IV melanoma at four time points during BRAF/MEK inhibitor treatment, and the BRAF genotype was analyzed in CTCs isolated from one patient.

RESULTS

We examined CTCs in patients with stage 0-III (five samples per stage: stage 0-I, stage II, and stage III), and detected CTCs even in patients with early disease (stage 0 and I). Interestingly, recurrence occurred in the lymph nodes of one stage I patient 2 years after the detection of a high number of CTCs in the patient's blood. The total number of CTCs in four of five patients with stage IV melanoma fluctuated in response to BRAF/MEK inhibitor treatment, suggesting that CTC number has potential for use as a drug response marker in advanced disease patients. Interestingly, one of those patients had CTCs harboring seven different BRAF genotypes, and the mutated CTCs disappeared upon BRAF/MEK inhibitor treatment, except for those harboring BRAF^A598V.

CONCLUSIONS

CTCs are present even in the early stage of melanoma, and the number of CTCs seems to reflect patients' responses to BRAF/MEK inhibitor treatment. Furthermore, genetic heterogeneity of BRAF may contribute to resistance to BRAF/MEK inhibitors. Our findings demonstrate the usefulness of CTC analysis for monitoring responses to targeted therapies in melanoma patients, and for understanding the mechanism of drug resistance.

Visualizing cancer extravasation: from mechanistic studies to drug development

Metastasis is a multistep process that accounts for the majority of cancer-related death. By the end of metastasize dissemination, circulating tumor cells (CTC) need to extravasate the blood vessels at metastatic sites to form new colonization. Although cancer cell extravasation is a crucial step in cancer metastasis, it has not been successfully targeted by current anti-metastasis strategies due to the lack of a thorough understanding of the molecular mechanisms that regulate this process. This review focuses on recent progress in cancer extravasation visualization techniques, including the development of both in vitro and in vivo cancer extravasation models, that shed light on the underlying mechanisms. Specifically, multiple cancer extravasation stages, such as the adhesion to the endothelium and transendothelial migration, are successfully probed using these technologies. Moreover, the roles of different cell adhesive molecules, chemokines, and growth factors, as well as the mechanical factors in these stages are well illustrated. Deeper understandings of cancer extravasation mechanisms offer us new opportunities to escalate the discovery of anti-extravasation drugs and therapies and improve the prognosis of cancer patients.

The YAP/TEAD Axis as a New Therapeutic Target in Osteosarcoma: Effect of Verteporfin and CA3 on Primary Tumor Growth

Although some studies suggested that disruption of the Hippo signaling pathway is associated with osteosarcoma progression, the molecular mechanisms by which YAP regulates primary tumor growth is not fully clarified. In addition, the validation of YAP as a therapeutic target through the use of inhibitors in a preclinical model must be demonstrated. RNA-seq analysis and Kaplan-Meier assays identified a YAP signature in osteosarcoma patients and a correlation with patients' outcomes. Molecular and cellular analysis (RNAseq, PLA, immunoprecipitation, promoter/specific gene, proliferation, cell cycle assays) using overexpression of mutated forms of YAP able or unable to interact with TEAD, indicate that TEAD is crucial for YAP-driven cell proliferation and in vivo tumor growth. In addition, in vivo experiments using an orthotopic mice model of osteosarcoma show that two YAP/TEAD inhibitors, verteporfin and CA3, reduce primary tumor growth. In this context, in vitro experiments demonstrate that these inhibitors decrease YAP expression, YAP/TEAD transcriptional activity and cell viability mainly by their ability to induce cell apoptosis. We thus demonstrate that the YAP/TEAD signaling axis is a central actor in mediating primary tumor growth of osteosarcoma, and that the use of YAP inhibitors may be a promising therapeutic strategy against osteosarcoma tumor growth.

Extracellular Vesicles Are Key Regulators of Tumor Neovasculature

Tumor progression involves a series of biologically important steps in which the crosstalk between cancer cells and the surrounding environment is an important issue. Angiogenesis is a key tumorigenic phenomenon for cancer progression. Tumor-related extracellular vesicles (EVs) modulate the tumor microenvironment (TME) through cell-to-cell communication. Tumor cells in a hypoxic TME release more EVs than cells in a normoxic environment due to uncontrollable tumor proliferation. Tumor-derived EVs in the TME influence endothelial cells (ECs), which then play multiple roles, contributing to tumor angiogenesis, loss of the endothelial vascular barrier by binding to ECs, and subsequent endothelial-to-mesenchymal transition. In contrast, they also indirectly induce tumor angiogenesis through the phenotype switching of various cells into cancer-associated fibroblasts, the activation of tumor-associated ECs and platelets, and remodeling of the extracellular matrix. Here, we review current knowledge regarding the involvement of EVs in tumor vascular-related cancer progression.

Water soluble ionic Co(II), Cu(II) and Zn(II) diimine-glycinate complexes targeted to tRNA: structural description, in vitro comparative binding, cleavage and cytotoxic studies towards chemoresistant prostate cancer cells

Four new water soluble Co(ii), Cu(ii) and Zn(ii) ionic metal complexes (1-4) [Cu(diimine)(H2O)2(glycinate)]+[glycinate]-, [Co(diimine)(H2O)4]+[glycinate]- and [Zn(diimine) (H2O)4]+[glycinate]-, where diimine = 2,2'-bipyridine (1-3) and 1,10-phenanthroline (4) were synthesized and thoroughly characterized by spectroscopic and single X-ray crystallographic studies. Complex 1 possesses a triclinic crystal system with a penta-coordinated geometry whereas complexes 2-4 crystallized in an isostructural monoclinic system having distorted octahedral geometry. Density functional theory (DFT) studies for complexes 1-4 were performed to correlate their geometrical parameters and to calculate the energy of frontier molecular orbitals. The corroborative results of spectroscopic and voltammetric studies with ct-DNA and tRNA revealed that the complexes bind noncovalently via an electrostatic mode of binding with specificity for tRNA as compared to ct-DNA. Gel electrophoresis experiments revealed that all the complexes unwind the plasmid pBR322 DNA at low micromolar concentrations (2-9 μM) following an oxidative mechanism for Cu(ii) and Co(ii) complexes (1, 2 and 4) whereas the Zn(ii) complex (3) mediates DNA cleavage by the hydrolytic pathway. The tRNA cleavage showed concentration and time dependent activity of the complexes to promote RNA hydrolysis. Furthermore, the BSA binding ability of complexes 1-4 was monitored, which revealed that the complexes could quench the intrinsic fluorescence in a static manner. Complexes 1-4 were found to be non-toxic towards normal prostate epithelial cells, PNT2, but were potent against chemoresistant metastatic prostate cancer cells, Du145, with GI50 values ranging from 12.75-37 μM. Complexes 1 and 2 also showed cytotoxic activity against cancer stem cells having GI50 values of 14.70 and 14.90 μM, respectively. Molecular docking studies were performed with DNA and tRNA which further validated the spectroscopic analysis demonstrating the higher binding affinity of the complexes towards tRNA.

Sonic Hedgehog Signature in Pediatric Primary Bone Tumors: Effects of the GLI Antagonist GANT61 on Ewing's Sarcoma Tumor Growth

Simple Summary

The poor clinical outcomes for Osteosarcoma (OS) and Ewing’s sarcoma (ES) patients underscore the urgency of developing novel therapeutic strategies for these pathologies. In this context, the emerging role of Sonic hedgehog (SHH) signaling in cancer has been critically evaluated, focusing on the potential for targeting SHH signaling as an anticancer strategy. The aims of this work were (1) to highlight and to compare a possible SHH/Gli signature between OS and ES, (2) to strengthen our knowledge concerning the role of EWS-FLI1 in the SHH signature in ES and (3) to evaluate the effect of the specific Gli inhibitor GANT61 in vivo on the growth of ES tumors using an orthotopic mice model. Our work identifies Gli1 as a promising therapeutic target in ES and demonstrates that GANT61, through inhibition of Gli1 transcriptional activity, may be a promising therapeutic strategy hindering ES tumor progression, and specifically primary tumor growth.

Abstract

Osteosarcoma (OS) and Ewing’s sarcoma (ES) are the most common malignant bone tumors in children and adolescents. In many cases, the prognosis remains very poor. The Sonic hedgehog (SHH) signaling pathway, strongly involved in the development of many cancers, regulate transcription via the transcriptional factors Gli1-3. In this context, RNAseq analysis of OS and ES cell lines reveals an increase of some major compounds of the SHH signaling cascade in ES cells, such as the transcriptional factor Gli1. This increase leads to an augmentation of the transcriptional response of Gli1 in ES cell lines, demonstrating a dysregulation of Gli1 signaling in ES cells and thus the rationale for targeting Gli1 in ES. The use of a preclinical model of ES demonstrates that GANT61, an inhibitor of the transcriptional factor Gli1, reduces ES primary tumor growth. In vitro experiments show that GANT61 decreases the viability of ES cell, mainly through its ability to induce caspase-3/7-dependent cell apoptosis. Taken together, these results demonstrates that GANT61 may be a promising therapeutic strategy for inhibiting the progression of primary ES tumors.

The diagnostic value of DNA repair gene in breast cancer metastasis

Breast cancer is the most common malignant tumor in China and even in the world. DNA repair genes can lead to tumor metastasis by affecting cancer cell resistance. Studies have preliminarily shown that DNA repair genes are related to breast cancer metastasis, but it is not clear whether they can be used as a prediction of the risk of breast cancer metastasis. Therefore, this study mainly discusses the predictive value of DNA repair genes in postoperative metastasis of breast cancer. The nested case–control method was used in patients with breast cancer metastasis after surgery (n = 103) and patients without metastasis after surgery (n = 103). The proteins and mRNA of DNA repair genes were detected by immunohistochemistry and Real-time PCR respectively. In protein expression, PARP1 (OR 1.147, 95% CI 1.067 ~ 1.233, P < 0.05), XRCC4 (OR 1.088, 95% CI 1.015 ~ 1.166, P < 0.05), XRCC1 (OR 1.114, 95% CI 1.021 ~ 1.215, P < 0.05), ERCC1 (OR 1.068, 95% CI 1.000 ~ 1.141, P < 0.10) were risk factors for postoperative metastasis of breast cancer. In addition, we used the ROC curve to study the optimal critical values of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA combined with the Youden index, and the effects of MSH2, MLH1, PARP1, XRCC1, XRCC4, 53BP1, ERCC1 and XPA on breast cancer metastasis were verified again. Among them, the risk of metastasis in the PARP1 high expression group was 3.286 times that of the low expression group (OR 3.286, 95% CI 2.013 ~ 5.364, P < 0.05). The risk of metastasis in the XRCC4 high expression group was 1.779 times that of the low expression group (OR 1.779, 95% CI 1.071 ~ 2.954, P < 0.05). The risk of metastasis in patients with ERCC1 high expression group was 2.012 times that of the low expression group (OR 2.012, 95% CI 1.056 ~ 3.836, P < 0.05). So we can conclude that protein expression of PARP1 (cut-off value = 6, Se = 76.70%, Sp = 79.61%), XRCC4 (cut-off value = 6, Se = 78.64%0, Se = 79.61%), ERCC1 (cut-off value = 3, Se = 89.32%, Sp = 50.49%), suggesting that when the PARP1 score is higher than 6 or the XRCC4 score is higher than 6 or the ERCC1 score is higher than 3, the risk of metastasis will increases. Due to PARP1, XRCC4 and ERCC1 belong to a part of DNA repair gene system, and the three proteins are positively correlated by correlation analysis (r_PARP1-XRCC4 = 0.343; r_PAPR1-ERCC1 = 0.335; r_XRCC4-ERCC1 = 0.388). The combined diagnosis of the PARR1, XRCC4 and ERCC1 have greater predictive value for the risk of metastasis of breast cancer (Se = 94.17%, Sp = 75.73%; OR 11.739, 95% CI 2.858 ~ 40.220, P < 0.05). The postoperative metastasis of breast cancer could be effectively predicted when the immunohistochemical scores met PARP1 (IHC score) > 6, XRCC4 (IHC score) > 6 and ERCC1 (IHC score) > 3. In addition, the combined diagnosis of PARP1, XRCC4 and ERCC1 has great predictive value for the risk of breast cancer metastasis.

(Pro)renin receptor/ATP6AP2 is required for autophagy and regulates proliferation in lung adenocarcinoma cells

(Pro)renin receptor ((P)RR)/ ATP6AP2 (ATPase, H⁺ transporting, lysosomal accessory protein 2) functions as an essential accessory subunit of vacuolar H⁺ -ATPase (V-ATPase). V-ATPase is necessary for lysosome function and autophagy. Autophagy is related to cell proliferation, migration and invasion of various cancer cells. In this study, we aim to clarify the relationship between (P)RR and autophagy in lung adenocarcinoma. Expression of (P)RR and Ki-67 (a proliferation marker) was studied in sixty-four adenocarcinoma cases by immunohistochemistry. Lung adenocarcinoma cell line, A549, was transfected with (P)RR-specific siRNA. Autophagy inhibitors, bafilomycin A1 and chloroquine, were used as positive controls. Cell proliferation and migration were measured by WST-8 assay and wound healing assay. Autophagosome markers, p62 and LC3, were analyzed by RT-qPCR, Western blot and immunocytochemistry. Immunohistochemistry showed that (P)RR was expressed in all adenocarcinoma tissues. The intensity of (P)RR immunoreactivity was significantly associated with Ki-67. Treatment of (P)RR-specific siRNA suppressed (P)RR expression and significantly reduced cell proliferation and migration as did the autophagy inhibitors. Western blot and immunocytochemistry showed that (P)RR-specific siRNA, as well as the autophagy inhibitors, induced p62 and LC3 accumulation in cytoplasmic granules. These results suggest that (P)RR is involved in cell proliferation and progression of lung adenocarcinoma via regulating autophagy.

NF-кB inhibition by DHMEQ: in vitro antiproliferative effects on pilocytic astrocytoma and concise review of the current literature

INTRODUCTION

Pilocytic astrocytoma (PA) is the most common brain tumor that affects the pediatric population. Even though PA is benign and treatment only involves surgery, recurrent or unresectable tumors require chemo- and radiotherapy. Besides BRAF, CDKN2A, or IDH mutations, the hyperactivation of the nuclear factor NF-κB contributes to tumor growth and survival.

METHODS

In the present study, we used publicly available data for the in silico analysis of NF-κB subunits (RELA, RELB, REL, NF-κB1, and NF-κB2) expression in PA samples. Besides, in vitro assays were performed to evaluate proliferation, migration, cell death, on the PA cell line Res286 comparing to human primary astrocytes. Sensitization to radiation therapy and temozolomide (TMZ) was also assayed.

RESULTS

Our results showed that all the members of the NF-kB family are upregulated in PA datasets compared to normal brain tissues. Moreover, DHMEQ treatment significantly reduced cell growth and motility, while sensitized cells to ionizing radiation and TMZ, as previously seen in high-grade gliomas.

CONCLUSIONS

This drug presents a potential application in clinical practice for the treatment of recurrent or inoperable PA. Moreover, its use might assist adjuvant chemotherapy and reduce irradiation doses to avoid toxicity to the surrounding tissues.

Beyond gold nanoparticles cytotoxicity: Potential to impair metastasis hallmarks

Gold nanoparticle (AuNP)-based systems have been extensively investigated as diagnostic and therapeutic agents due to their tunable properties and easy surface functionalization. Upon cell uptake, AuNPs present an inherent cell impairment potential based on organelle and macromolecules damage, leading to cell death. Such cytotoxicity is concentration-dependent and completely undesirable, especially if unspecific. However, under non-cytotoxic concentrations, internalized AuNPs could potentially weaken cells and act as antitumor agents. Therefore, this study aimed to investigate the antitumor effect of ultrasmall AuNPs (~3 nm) stabilized by the anionic polysaccharide gum arabic (GA-AuNPs). Other than intrinsic cytotoxicity, the focus was downregulation of cancer hallmarks of aggressive tumors, using a highly metastatic model of melanoma. We first demonstrated that GA-AuNPs showed excellent stability under biological environment. Non-cytotoxic concentrations to seven different cell lines, including tumorigenic and non-tumorigenic cells, were determined by standard 2D in vitro assays. Gold concentrations ≤ 2.4 mg L^-1 (16.5 nM AuNPs) were non-cytotoxic and therefore chosen for further analyses. Cells exposed to GA-AuNPs were uptaken by melanoma cells through endocytic processes. Next we described remarkable biological properties using non-cytotoxic concentrations of this nanomaterial. Invasion through an extracellular matrix barrier as well as 3D growth capacity (anchorage-independent colony formation and spheroids growth) were negatively affected by 2.4 mg L^-1 GA-AuNPs. Additionally, exposed spheroids showed morphological changes, suggesting that GA-AuNPs could penetrate into the preformed tumor and affect its integrity. All together these results demonstrate that side effects, such as cytotoxicity, can be avoided by choosing the right concentration, nevertheless, preserving desirable effects such as modulation of key tumor cell malignancy features.

Circular RNA circRPPH1 promotes triple-negative breast cancer progression via the miR-556-5p/YAP1 axis

Circular RNAs (circRNAs), which are considered to be important functional regulators in cancer, have provided a new perspective regarding our understanding of tumor biology, including that of breast cancer. To investigate the regulatory effect of circRPPH1 on cellular behaviors of breast cancer and the potential mechanism, the expression of circRPPH1 and miR-556-5p in breast cancer tissues and cell lines were examined by quantitative RT-PCR. The regulatory effects of the circRPPH1/miR-556-5p/YAP1 axis on cellular behaviors of breast cancer cells were evaluated through functional experiments in vitro and tumor growth in vivo. The relationship between circRPPH1 and miR-556-5p/YAP1 was assessed using dual-luciferase reporter and RNA immunoprecipitation assays. PCR results showed that circRPPH1 levels were significantly upregulated in tumor tissues and breast cancer cells. Functionally, circRPPH1 promoted the proliferation, migration, invasion, and angiogenesis of breast cancer cell lines and tumor growth in vivo. Regarding the mechanism, dual-luciferase reporter and RNA immunoprecipitation assays showed that circRPPH1 was capable of sponging miR-556-5p to increase expression of the oncogene YAP1. Our data reveal that circRPPH1 plays a vital regulatory role in breast cancer via the miR-556-5p/YAP1 axis and may serve as a promising therapeutic target for breast cancer treatment.

Circulating Tumor DNA as a Prognostic Biomarker in Localized Non-small Cell Lung Cancer

Background

Routine clinical surveillance involves serial radiographic imaging following radical surgery in localized non-small cell lung cancer (NSCLC). However, such surveillance can detect only macroscopic disease recurrence and is frequently inconclusive. We investigated if detection of ctDNA before and after resection of NSCLC identifies the patients with risk of relapse, and furthermore, informs about response to management.

Methods

We recruited a total of 77 NSCLC patients. A high-throughput 127 target-gene capture technology and a high-sensitivity circulating single-molecule amplification and resequencing technology (cSMART) assay were used to detect the somatic mutations in the tumor tissues as well as the plasma of NSCLC patients before and after surgery to monitor for minimal residual disease (MRD). Kaplan-Meier and Cox regression analysis were performed to evaluate the relapse-free survival (RFS) and overall survival (OS) of patients with predictor variables.

Results

Patients with a higher stage (III/IV) and preoperative ctDNA-positive status demonstrated a significant 2.8-3.4-fold risk and 3.8-4.0-fold risk for recurrence and death, respectively. Preoperative ctDNA-positive patients associated with a lower RFS (HR = 3.812, p = 0.0005) and OS (HR = 5.004, p = 0.0009). Postoperative ctDNA-positive patients also associated with a lower RFS (HR = 3.076, p = 0.0015) and OS (HR = 3.195, p = 0.0053). Disease recurrence occurred among 63.3% (19/30) of postoperative ctDNA-positive patients. Most of these patients 89.5% (17/19) had detectable ctDNA within 2 weeks after surgery and was identified in advance of radiographic findings by a median of 12.6 months.

Conclusion

Advanced stage and preoperative ctDNA-positive are strong predictors of RFS and OS in localized NSCLC patients undergoing complete resection. Postoperative detection of ctDNA increases chance to detect early relapse, thus can fulfill an important role in stratifying patients for immediate further treatment with adjuvant and neoadjuvant therapy.

GO Nanosheets: Promising Nano Carrier for the S29, 1-(2-Chloro-2-(4-chlorophenyl-ethyl)-N-(4-fluorobenzyl)-1H-pyrazolo[3,4-d] pyrimidin-4-amine, Therapeutic Agent in Neuroblastoma

Graphene oxide (GO) derivatives are reported as a valid alternative to conventional carriers of therapeutic agents, because they have a large surface area, an excellent electrical and thermal conductivity and a great capacity for selective binding of drugs and therapeutics, due to the functionalization of their surfaces, edges and sides. In this work GO nanosheets, synthesized by electrochemical exfoliation of graphite (patent N 102015000023739, Tor Vergata University), were investigated as possible carriers of an anticancer drug, the S29, an inhibitor of a cytoplasmic tyrosine kinase (c-SRC) on a neuroblastoma cell line (SK N BE 2 cells). Neuroblastoma is a heterogenous tumor whose characteristics range from spontaneous regression to aggressive phenotypes that are due to different mutations that often occur in SRC family kinases. Inhibitors of tyrosine kinases are currently investigated for their anti-tumoral effects on aggressive neuroblastomas, but their uptake in cells and pharmacokinetics needs to be improved. In this work S29 was stably conjugated with highly water-dispersible GO nanoparticles. S29/GO complex formation was induced by 1h sonication and its stability was analyzed by chromatography coupled with spectrophotometry and mass spectrometry. The synthesized composite (GO-S29) was delivered into SK N BE 2 cells and its effects on cell viability, production of reactive oxygen species (ROS) and migration were studied. The results show that the compound GO-S29 exerts anti-tumoral effects on the neuroblastoma cell line, higher than both GO and S29 do alone and that GO has an additive effect on S29.

Role of exosomes in malignant glioma: microRNAs and proteins in pathogenesis and diagnosis

Malignant gliomas are the most common and deadly type of central nervous system tumors. Despite some advances in treatment, the mean survival time remains only about 1.25 years. Even after surgery, radiotherapy and chemotherapy, gliomas still have a poor prognosis. Exosomes are the most common type of extracellular vesicles with a size range of 30 to 100 nm, and can act as carriers of proteins, RNAs, and other bioactive molecules. Exosomes play a key role in tumorigenesis and resistance to chemotherapy or radiation. Recent evidence has shown that exosomal microRNAs (miRNAs) can be detected in the extracellular microenvironment, and can also be transferred from cell to cell via exosome secretion and uptake. Therefore, many recent studies have focused on exosomal miRNAs as important cellular regulators in various physiological and pathological conditions. A variety of exosomal miRNAs have been implicated in the initiation and progression of gliomas, by activating and/or inhibiting different signaling pathways. Exosomal miRNAs could be used as therapeutic agents to modulate different biological processes in gliomas. Exosomal miRNAs derived from mesenchymal stem cells could also be used for glioma treatment. The present review summarizes the exosomal miRNAs that have been implicated in the pathogenesis, diagnosis and treatment of gliomas. Moreover, exosomal proteins could also be involved in glioma pathogenesis. Exosomal miRNAs and proteins could also serve as non-invasive biomarkers for prognosis and disease monitoring. Video Abstract.

DNA polymerase beta modulates cancer progression via enhancing CDH13 expression by promoter demethylation

DNA polymerase β (Pol β) plays a critical role in DNA base excision repair (BER), which is involved in maintaining genomic stability and in the modulation of DNA demethylation. Numerous studies implicated deficiency of Pol β in the genomic instability and dysregulation of genes expression, leading to affecting initiation of cancer. However, the role of Pol β in cancer progression is still unclear. Here, we show that Pol β depresses migratory and invasive capabilities of both breast and lung carcinomas, which were evident in human breast and lung cancer cells, as well as in mouse xenograft tumors. On the molecular basis, overexpression of Pol β enhanced expression of CDH13, which show function on cell adhesion and migration. Knockdown of CDH13 restores the migratory, invasive capabilities and angiogenesis in tumor, which gets impaired by Pol β. According to the function of BER on modulation of DNA demethylation, our studies on CDH13 expression and the DNA methylation levels of CDH13 promoter suggested that Pol β promotes expression of CDH13 by augmenting DNA demethylation of CDH13 promoter. Our findings elucidated a novel possibility that Pol β impair cancer cell metastasis during cancer progression and shed light on the role of Pol β in cancer therapy.

Immune cells as tumor drug delivery vehicles

This review article describes the use of immune cells as potential candidates to deliver anti-cancer drugs deep within the tumor microenvironment. First, the rationale of using drug carriers to target tumors and potentially decrease drug-related side effects is discussed. We further explain some of the current limitations when using nanoparticles for this purpose. Next, a comprehensive step-by-step description of the migration cascade of immune cells is provided as well as arguments on why immune cells can be used to address some of the limitations associated with nanoparticle-mediated drug delivery. We then describe the benefits and drawbacks of using red blood cells, platelets, granulocytes, monocytes, macrophages, myeloid-derived suppressor cells, T cells and NK cells for tumor-targeted drug delivery. An additional section discusses the versatility of nanoparticles to load anti-cancer drugs into immune cells. Lastly, we propose increasing the circulatory half-life and development of conditional release strategies as the two main future pillars to improve the efficacy of immune cell-mediated drug delivery to tumors.

Small Ones to Fight a Big Problem-Intervention of Cancer Metastasis by Small Molecules

Metastasis represents the most lethal attribute of cancer and critically limits successful therapies in many tumor entities. The clinical need is defined by the fact that all cancer patients, who have or who will develop distant metastasis, will experience shorter survival. Thus, the ultimate goal in cancer therapy is the restriction of solid cancer metastasis by novel molecularly targeted small molecule based therapies. Biomarkers identifying cancer patients at high risk for metastasis and simultaneously acting as key drivers for metastasis are extremely desired. Clinical interventions targeting these key molecules will result in high efficiency in metastasis intervention. In result of this, personalized tailored interventions for restriction and prevention of cancer progression and metastasis will improve patient survival. This review defines crucial biological steps of the metastatic cascade, such as cell dissemination, migration and invasion as well as the action of metastasis suppressors. Targeting these biological steps with tailored therapeutic strategies of intervention or even prevention of metastasis using a wide range of small molecules will be discussed.

Association of polymorphisms in metastasis suppressor genes NME1 and KISS1 with breast cancer development and metastasis

BACKGROUND

NME1 and KISS1 genes are two tumor metastasis suppressor genes, mapped to chromosomes 17q21.3 and 1q32 respectively. Here, we analyzed the association of EcoR1 (rs34214448-G/T) polymorphism in NME1 gene and 9 del T (rs5780218-A/-) polymorphism in KISS1 gene with breast cancer development and metastasis.

RESULTS

The study included 75 women newly diagnosed with breast cancer recruited from Oncology Center at Mansoura University Hospitals and 37 age-matched healthy female volunteers as a control group. DNA was extracted from peripheral blood samples and genotyping of rs34214448 and rs5780218 SNPs was carried out by PCR-RFLP technique. NME1 EcoR1 (rs34214448) polymorphism has a statistically significant association with breast cancer risk (P < 0.001). Most of breast cancer group (55%) had heterozygous (G/T) genotype while most of control group (95%) had homozygous wild (G/G) genotype (P < 0.0005). Also, KISS1 rs5780218 polymorphism has a statistically significant association with breast cancer risk. The wild (A/A) genotype was associated with lower risk of breast cancer (A/- + -/- vs. A/A: OR = 3.1, 95% CI = 1.15-8.36, P = 0.025). EcoR1 (rs34214448) polymorphism revealed a significant association with tumor stage and distant metastasis as patients. Carriers of the wild (G/G) genotype were more likely to present with advanced disease stages and distant metastasis.

CONCLUSIONS

Both EcoR1 (rs34214448) polymorphism of NME1 gene and rs5780218 polymorphism of KISS1 gene revealed significant association with increased risk of breast cancer development. The (G/G) genotype of EcoR1 polymorphism was associated with higher risk of breast cancer metastasis.

P2Y2R has a significant correlation with Notch-4 in patients with breast cancer

Our previous study found that highly metastatic breast cancer cells, such as MDA-MB-231 cells, release higher levels of ATP and exhibit greater P2Y₂ receptor (P2Y₂R) activity than lowly metastatic breast cancer cells, and that P2Y₂R activation mediated by ATP plays a significant role in tumor progression and metastasis. In addition, we reported that radiotherapy-resistant (RT-R) breast cancer cells promote invasion and tumor growth through the activation of P2Y₂R by ATP released from RT-R-breast cancer cells than breast cancer cells. Moreover, increased numbers of cancer stem cells (CSCs) were observed among the RT-R-breast cancer cell population. Therefore, in this study, we investigated the expression level of five CSC markers (CD24, CD44, Oct3/4, Notch-4 and ALDH1A1) as well as P2Y₂R in the tumor tissues of patients with breast cancer and determined which CSC marker correlates with P2Y₂R in breast cancer. According to the immunohistochemical analysis, CD44, Oct3/4 and Notch-4 but not ALDH1A1 were significantly expressed in the tumor tissues (n=180) compared with the normal epithelial tissues (n=20) of patients with breast cancer. It was demonstrated that P2Y₂R expression was increased in tumor tissues of patients with breast cancer compared with normal epithelial tissue. Notably, it was identified that P2Y₂R expression has a significant correlation with only the CSC marker Notch-4 in patients with breast cancer. The results of this study suggested for the first time to the best of our knowledge that Notch-4 has a notable correlation with P2Y₂R, which has important roles in tumor progression and metastasis.

KIF15 facilitates gastric cancer via enhancing proliferation, inhibiting apoptosis, and predict poor prognosis

Background

Kinesin superfamily proteins (KIFs) can transport membranous organelles and protein complexes in an ATP-dependent manner. Kinesin family member 15 (KIF15) is overexpressed in various cancers. However, the function of KIF15 in gastric cancer (GC) is still unclear.

Methods

GC patients’ data from The Cancer Genome Atlas (TCGA) were analyzed by bioinformatics methods. The expression of KIF15 was examined in GC and paracarcinoma tissues from 41 patients to verify the analysis results. The relationship between KIF15 expression and clinical characteristics were also observed by bioinformatics methods. Kaplan–Meier survival analysis of 122 GC patients in our hospital was performed to explore the relationship between KIF15 expression levels and GC patients’ prognosis. KIF15 was downregulated in GC cell lines AGS and SGC-7901 by transfecting a lentivirus-mediated shRNA plasmid targeting KIF15. In vitro, GC cell proliferation and apoptosis were detected by MTT assay, colony formation assay, and Annexin V-APC staining. In vivo, xenograft experiments were used to verify the in vitro results. Furthermore, Human Apoptosis Antibody Array kit was used to screen possible targets of KIF15 in GC cell lines.

Results

The bioinformatics results showed that KIF15 expression levels were higher in GC tissues than in normal tissues. IHC showed same results. High expression of KIF15 was statistical correlated with high age and early histologic stage. Kaplan–Meier curves indicated that high KIF15 expression predict poor prognosis in patients with GC. MTT assay and colony formation assay showed that KIF15 promote GC cell proliferation. Annexin V-APC staining found that KIF15 can inhibit GC cell apoptosis. Xenograft experiments reveal that downregulating KIF15 can inhibit GC tumor growth and promote GC apoptosis. Through detection of 43 anti-apoptotic proteins by the Human Apoptosis Antibody Array kit, it was confirmed that knocking down KIF15 can reduce seven anti-apoptotic proteins expression.

Conclusions

Taken together, our study revealed a critical role for KIF15 to inhibit GC cell apoptosis and promote GC cell proliferation. KIF15 may decrease anti-apoptotic proteins expression by regulating apoptosis pathways. High expression of KIF15 predicts a poor prognosis in patients with GC. KIF15 might be a novel prognostic biomarker and a therapeutic target for GC.

Cancer of Unknown Primary Site: Real Entity or Misdiagnosed Disease?

Metastasis is a late event in the progression of any tumour. However, invasive cancers are occasionally detected in the form of metastatic lesions without a clearly detectable primary tumour. Cancer of unknown primary site (CUP) is defined as a confirmed metastatic tumour, with unknown primary tumour site, despite the standardized diagnostic approach that includes clinical history, routine laboratory tests, and complete physical examination. Due to the lack of basic research on its primary causes, CUP is appropriately termed an 'orphan' cancer. Nevertheless, CUP accounts for 2-5% of diagnosed malignancies. To date, it is unclear whether CUP is an entity with primary dormancy as its hallmark or an entity with genetic abnormalities that cause it to manifest as a primary metastatic disease. In this review, we discuss different aspects of CUP, including its current diagnostic methods, angiogenesis effectors, relationship with cancer stem cells and current treatments.