Implementation of antibody-drug conjugates in HER2-positive solid cancers: Recent advances and future directions.

In recent decades, there has been a surge in the approval of monoclonal antibodies for treating a wide range of hematological and solid malignancies. These antibodies exhibit exceptional precision in targeting the surface antigens of tumors, heralding a groundbreaking approach to cancer therapy. Nevertheless, monoclonal antibodies alone do not show sufficient lethality against cancerous cells compared to chemotherapy. Consequently, a new class of anti-tumor medications, known as antibody-drug conjugates (ADCs), has been developed to bridge the divide between monoclonal antibodies and cytotoxic drugs, enhancing their therapeutic potential. ADCs are chemically synthesized by binding tumor-targeting monoclonal antibodies with cytotoxic payloads through linkers that are susceptible to cleavage by intracellular proteases. They combined the accurate targeting of monoclonal antibodies with the potent efficacy of cytotoxic chemotherapy drugs while circumventing systemic toxicity and boasting superior lethality over standalone targeted drugs. The human epidermal growth factor receptor (HER) family, which encompasses HER1 (also known as EGFR), HER2, HER3, and HER4, plays a key role in regulating cellular proliferation, survival, differentiation, and migration. HER2 overexpression in various tumors is one of the most frequently targeted antigens for ADC therapy in HER2-positive cancers. HER2-directed ADCs have emerged as highly promising treatment modalities for patients with HER2-positive cancers. This review focuses on three approved anti-HER2 ADCs (T-DM1, DS-8201a, and RC48) and reviews ongoing clinical trials and failed trials based on anti-HER2 ADCs. Finally, we address the notable challenges linked to ADC development and underscore potential future avenues for tackling these hurdles.

Knowledge mapping and current trends of Warburg effect in the field of cancer.

Background: Since abnormal aerobic glycolysis was first identified in cancer cells, many studies have focused on its mechanisms. The purpose of this study was to analyze the global research status of the Warburg effect in cancer using bibliometrics. Methods: Articles published from 01 January 2013 to 31 December 2022 (n=2,067) were retrieved from the Web of Science core collection database and analyzed using VOSviewer and CiteSpace software. Results: Over the past decade, there was an overall increase in the number of annual publications. China was the most productive country with 790 articles, while the United States received the most citations, with 25,657 citations in total. Oncotarget was the most productive and most cited journal, with 99 articles and 4,191 citations, respectively. International cooperation was common, with the USA cooperating most with other countries. Lactate metabolism, citrate production, and non-coding RNAs related to the Warburg effect have received increasing attention in cancer research. These areas may become future research trends. Conclusion: The study findings help summarize the research status and hotspots of the Warburg effect cancer, and will inform subsequent research.

Novel agents and clinical trials in castration-resistant prostate cancer: latest updates from 2023 ASCO-GU Cancers Symposium.

Numerous novel and effective therapeutic agents and clinical trials addressing castration-resistant prostate cancer (CRPC) were reported during the 2023 American Society of Clinical Oncology-Genitourinary (ASCO-GU) Cancers Symposium. Notably, radionuclide drug conjugates (RDC), specifically 177Lu/111In-J591 and 225Ac-J591, exhibited enhanced therapeutic efficacy in treating patients with CRPC. Furthermore, promising treatment approaches for CRPC included dual anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and anti-programmed death-1 (PD-1) blockade in rare tumors (DART)-Lorigerlimab, prostate stem cell antigen (PSCA)-directed chimeric antigen receptor (CAR)-T cell immunotherapy-BPX-601, and protein kinase inhibitor (AKTi)-CAPltello-280. We have summarized the latest CRPC treatment strategies presented at the 2023 ASCO-GU Cancers Symposium, along with recent advances in CRPC clinical trials.

Liquid biopsy in urothelial carcinoma: Detection techniques and clinical applications.

The types of urothelial carcinoma (UC) include urothelial bladder cancer and upper tract urothelial carcinoma. Current diagnostic techniques cannot meet the needs of patients. Liquid biopsy is an accurate method of determining the molecular profile of UC and is a cutting-edge and popular technique that is expected to complement existing detection techniques and benefit patients with UC. Circulating tumor cells, cell-free DNA, cell-free RNA, extracellular vesicles, proteins, and metabolites can be found in the blood, urine, or other bodily fluids and are examined during liquid biopsies. This article focuses on the components of liquid biopsies and their clinical applications in UC. Liquid biopsies have tremendous potential in multiple aspects of precision oncology, from early diagnosis and treatment monitoring to predicting prognoses. They may therefore play an important role in the management of UC and precision medicine.

Blood-based liquid biopsy: insights into early detection, prediction, and treatment monitoring of bladder cancer.

Bladder cancer (BC) is a clinical challenge worldwide with late clinical presentation, poor prognosis, and low survival rates. Traditional cystoscopy and tissue biopsy are routine methods for the diagnosis, prognosis, and monitoring of BC. However, due to the heterogeneity and limitations of tumors, such as aggressiveness, high cost, and limited applicability of longitudinal surveillance, the identification of tumor markers has attracted significant attention in BC. Over the past decade, liquid biopsies (e.g., blood) have proven to be highly efficient methods for the discovery of BC biomarkers. This noninvasive sampling method is used to analyze unique tumor components released into the peripheral circulation and allows serial sampling and longitudinal monitoring of tumor progression. Several liquid biopsy biomarkers are being extensively studied and have shown promising results in clinical applications of BC, including early detection, detection of microscopic residual disease, prediction of recurrence, and response to therapy. Therefore, in this review, we aim to provide an update on various novel blood-based liquid biopsy markers and review the advantages and current limitations of liquid biopsy in BC therapy. The role of blood-based circulating tumor cells, circulating tumor DNA, cell-free RNA, exosomes, metabolomics, and proteomics in diagnosis, prognosis, and treatment monitoring, and their applicability to the personalized management of BC, are highlighted.

Oxidative Stress: A Putative Link Between Lower Urinary Tract Symptoms and Aging and Major Chronic Diseases.

Aging and major chronic diseases are risk factors for lower urinary tract symptoms (LUTS). On the other hand, oxidative stress (OS) is one of the fundamental mechanisms of aging and the development of chronic diseases. Therefore, OS might be a candidate mechanism linking these two clinical entities. This article aims to summarize the studies on the prevalence of LUTS, the role of OS in aging and chronic diseases, and the potential mechanisms supporting the putative link. A comprehensive literature search was performed to identify recent reports investigating LUTS and OS in major chronic diseases. In addition, studies on the impact of OS on the lower urinary tract, including bladder, urethra, and prostate, were collected and summarized. Many studies showed LUTS are prevalent in aging and major chronic diseases, including obesity, metabolic syndrome, diabetes, cardiovascular disease, hypertension, obstructive sleep apnea, autoimmune diseases, Alzheimer's disease, and Parkinson's disease. At the same time, OS is a key component in the pathogenesis of those chronic diseases and conditions. Recent studies also provided evidence that exacerbated OS can cause functional and/or structural changes in the bladder, urethra, and prostate, leading to LUTS. The reviewed data support the concept that OS is involved in multiple risk factors-associated LUTS, although further studies are needed to confirm the causative relationship. The specific ROS/RNS and corresponding reactions/pathways involved in chronic diseases and associated LUTS should be identified in the future and could serve as therapeutic targets.

miRNA-373 promotes urinary bladder cancer cell proliferation, migration and invasion through upregulating epidermal growth factor receptor.

MicroRNA (miRNA)-373 has been demonstrated to be involved in several types of cancer, whereas its involvement in urinary bladder cancer and the mechanism of its function remains poorly understood. The present study aimed to investigate the functionality of miRNA-373 in urinary bladder cancer. Tumor tissues and adjacent healthy tissues were collected from patients with urinary bladder cancer (n=55), and blood samples were collected from patients with urinary bladder cancer and healthy controls (n=45). The expression of miRNA-373 in these tissues was detected by reverse transcription quantitative polymerase chain reaction. The diagnostic value of serum miRNA-373 for urinary bladder cancer was investigated by receiver operating characteristic curve analysis and survival curve analysis, respectively. miRNA-373 mimics were transfected into urinary bladder cancer cells, and the effects on cancer cell proliferation, migration and invasion, and on epidermal growth factor receptor (EGFR) expression was assessed by Cell Counting kit-8 assay, Transwell migration and invasion assays, and western blot analysis. It was identified that the miRNA-373 expression level was increased in tumor tissues compared with adjacent healthy tissues. The serum level of miRNA-373 was increased in patients with cancer compared with the healthy controls. Serum miRNA-373 may be used to accurately predict urinary bladder cancer. miRNA-373 overexpression promoted tumor cell proliferation, migration and invasion, and resulted in upregulated EGFR expression in urinary bladder cancer cells. It was concluded that miRNA-373 overexpression may promote urinary bladder cancer cell proliferation, migration and invasion by upregulating EGFR.

[Ultrasound characteristics of testicular Leydig cell tumors , , , 1.]

OBJECTIVE: To explore the color Doppler ultrasonic characteristics of testicular Leydig cell tumors (LCT) and improve the clinical diagnosis of the disease. METHODS: We retrospectively analyzed 4 cases of testicular LCT diagnosed and treated in our hospital and summarized the experience in the ultrasonic diagnosis of LCT with a review of the relevant literature. RESULTS: All the 4 testicular LCTs were solitary and quasi-round, 1 in the left and 3 in the right. The smallest mass was 1.8 × 1.5 cm and the largest 3.1 × 2.5 cm, and 2 were complicated by hydrocele of tunica vaginalis. The margins of tumors were distinct in 2 cases and indistinct in 1, and changed from distinct to indistinct in another during the follow-up. Hypoechoes were revealed in all the 4 cases in ultrasonography, 2 with abundant internal blood flow, 1 with abundant peripheral blood flow, and the other with abundant internal blood flow changed from circular blood flow surrounding the mass. CONCLUSIONS: A typical sporadic LCT was ultrasonically manifested as an isolated hypoechoic infracentimetric mass with a clear demarcation from the adjacent pulp. It exhibited intrinsic hypervascularization associated with a typical peripheral rim pattern. Larger lesions more often presented a lobulated shape and intense hypervascularization. Although these ultrasonic characteristics do not reveal the nature of LCT with certainty, they can help the surgeon with the decision on testis-sparing surgery or perhaps even on the active monitoring for the smallest lesions in a population with impaired fertility.

Regulation of Spontaneous Contractions in Intact Rat Bladder Strips and the Effects of Hydrogen Peroxide.

Enhanced spontaneous contractions are associated with overactive bladder. Elevated levels of reactive oxygen species might contribute to enhanced spontaneous contractions. We investigated the regulation of spontaneous contractions and the effects of hydrogen peroxide (H2O2) in intact rat bladder strips. The spontaneous contractions were measured using a tissue bath system. The vehicle or the specific activators/blockers were applied and followed by the application of 0.003 g% H2O2. The basal tension, amplitude, and frequency of spontaneous contractions were quantified. Nisoldipine and bisindolylmaleimide 1 had no effects on spontaneous contractions. SKF96365 and Y27632 decreased basal tension and amplitude. Ryanodine slightly increased frequency. Both iberiotoxin and NS-1619 increased amplitude. Apamin reduced frequency but increased amplitude. NS-309 inhibited both the amplitude and frequency. The basal tension and amplitude increased when H2O2 was applied. Pretreatment with NS-309 inhibited H2O2-elicited augmented amplitude and frequency, while pretreatment with Y-27632 inhibited the augmented basal tension. The combined application of NS-309 and Y27632 almost eliminated spontaneous contractions and its augmentation induced by H2O2. In conclusion, Ca2+ influx, Rho kinase activation, and SK channel inactivation play important roles in spontaneous contractions in intact bladder strips, whereas only latter two mechanisms may be involved in H2O2-elicited increased spontaneous contractions.

Downregulation of miR-133b predict progression and poor prognosis in patients with urothelial carcinoma of bladder.

We found microRNA-133b (miR-133b) was downregulated in urothelial carcinoma of the bladder (UCB) tissues, and it could inhibit the proliferation and induce apoptosis in UCB cells. Consequently, we intend to explore the clinical significance of miR-133b in UCB patients. Expression of miR-133b in 146 UCB specimens and matched adjacent non-neoplastic bladder tissues were measured by quantitative real-time polymerase chain reaction. The overall survival (OS) curve and progression-free survival (PFS) curve were plotted using the Kaplan-Meier method. Prognostic factors for OS and PFS were identified by univariate and multivariate analyses using the Cox proportional hazards regression model. The expression of miR-133b was significantly downregulated in UCB tissues compared with those in adjacent non-neoplastic bladder tissues (P < 0.001). Among UCB patients, low expression of miR-133b significantly correlated with aggressive clinicopathological features. Multivariate analysis indicated that the expression of miR-133b was the independent prognostic factors for predicting PFS (RR: 2.97; 95% CI: 1.78-6.44; P = 0.009) and OS (RR: 4.23; 95% CI: 1.51-11.8; P = 0.011) in patients with UCB. Our study demonstrated that downregulation of miR-133b associated with aggressive clinicopathological features and predicted unfavorable prognosis in patients with UCB, might serve as feasible biomarker for clinical outcome of UCB patients after surgery and potential therapeutic target in the future.

Clinical and oncological outcomes in Chinese patients with renal cell carcinoma and venous tumor thrombus extension: single-center experience.

BACKGROUND: To evaluate the clinical and oncological outcomes and to identify prognostic factors for survival in Chinese patients with renal cell carcinoma (RCC) and venous tumor thrombus (VTT). METHODS: A total of 86 patients who underwent nephrectomy and tumor thrombectomy for RCC and venous tumor thrombus extension from 2003 to 2013 were included in this retrospective study. The records of these patients were reviewed. Kaplan-Meier analysis was used to determine cancer-specific survival (CSS). Prognostic factors for CSS were identified by univariate and multivariate analyses using the Cox proportional hazards regression mode. RESULTS: All patients in this cohort received radical nephrectomy and tumor thrombectomy. Median follow-up period was 27.0 months (range 3-111). No patients died intraoperatively, and the complication rate was 36.0%. The 1-, 3-, and 5-year CSS rates for all patients were 93.0%, 70.9%, and 58.1%, respectively, and those for patients without distant metastasis at presentation were 95.3%, 82.6%, and 68.6%, respectively. Multivariate Cox regression analysis showed that lymph node invasion, distant metastasis at presentation, and invasion of the inferior vena cava (IVC) wall were the independent prognostic factors for CSS in all patients. For patients without distant metastasis, tumor grade, lymph node invasion, and perinephric fat invasion were significantly associated with CSS on multivariate analysis. CONCLUSIONS: Survival rates for patients with RCC and VTT were still poor. Our results indicated that lymph node invasion, distant metastasis at presentation, and invasion of the IVC wall were independent negative prognostic factors.

In Vivo Evaluation of Chemical Composition of Eight Types of Urinary Calculi Using Spiral Computerized Tomography in a Chinese Population.

BACKGROUND: This study was conducted to evaluate the chemical composition of eight types of urinary calculi using spiral computerized tomography (CT) in vivo. METHODS: From October 2011 to February 2013, upper urinary tract calculi were obtained from 122 patients in the department of urinary surgery of the First Affiliated Hospital of Soochow University. All patients were scanned with a 64-detector row helical CT scanner using 6.50 mm collimation before ureterorenoscopy. Data from the preoperative spiral CT scans and postoperative chemical composition of urinary calculi were collected. RESULTS: The chemical composition analysis indicates that there were five types of pure calculi and three types of mixed calculi, including 39 calcium oxalate calculi, 12 calcium phosphate calculi, 10 calcium carbonate calculi, 8 magnesium ammonium phosphate calculi, 6 carbonated apatite, 21 uric acid/ammonium urate calculi, 10 uric acid/calcium oxalate calculi, and 16 calcium oxalate/calcium phosphate calculi. There were significant differences in the mean CT values among the five types of pure calculi (P < 0.001). Furthermore, we also observed significant differences in the mean CT values among three types of mixed calculi (P < 0.001). Significant differences in the mean CT values were also found among eight types of urinary calculi (P < 0.001). However, no statistically significant difference was observed between the mean CT values of magnesium ammonium phosphate calculi and uric acid/calcium oxalate calculi (P = 0.262). CONCLUSION: Our findings suggest that spiral CT could be a promising tool for determining the chemical composition of upper urinary tract calculi.

MiR-133b regulates bladder cancer cell proliferation and apoptosis by targeting Bcl-w and Akt1.

BACKGROUND: MiR-133b is a muscle-specific microRNA; it has a role in the formation of cardiocytes and the expression of myocardium ion channels by regulating target genes. Many human malignant tumors demonstrate a low expression of miR-133b, as noted in colorectal, lung, esophagus and bladder cancers, but the role of miR-133b in bladder cancer is unknown. METHODS: The expression of miR-133b in clinical bladder cancer specimens and adjacent normal tissues was confirmed by stem-loop RT-PCR. We also analyzed the relationship between miR-133b expression and clinicopathological factors of bladder cancer. Bcl-w and Akt1 protein expression in 41 bladder cancer specimens and adjacent normal tissues was detected by Western blot. After transfection of miR-133b mimics or inhibitor into a T24 human bladder cancer cell line, Bcl-w and Akt1 protein and mRNA expression were examined by Western blot and RT-PCR, respectively. The effect of miR-133b on T24 cell proliferation and apoptosis was measured by CCK-8 tests and flow cytometry, respectively. RESULTS: The expression of miR-133b in bladder cancer tissues from 41 patients was significantly down-regulated (P < 0.01); low expression of miR-133b was strongly associated with high-grade bladder cancer (P < 0.01). Bcl-w and Akt1 proteins were significantly overexpressed in bladder cancer tissues versus adjacent normal tissues (P < 0.01 for both). The expression of Akt1 and Bcl-w proteins and Akt1 mRNA, in T24 cells was significantly down-regulated or up-regulated after transfection of miR-133b mimics or inhibitor, respectively; however, there was no significant difference in Bcl-w mRNA expression. Transfection of HEK-293 T cells with miR-133b significantly suppressed a luciferase-reporter containing the Bcl-w or Akt 1 3'-untranslated regions. MiR-133b mimics significantly inhibited T24 cell proliferation, as well as increased T24 cell apoptosis (P < 0.05 and P < 0.01, respectively) while the miR-133b inhibitor increased and decreased these, respectively (P < 0.05 for both). CONCLUSIONS: MiR-133b may play a very important role in the proliferation and apoptosis of T24 cells by regulating the expression of Bcl-w and Akt1.

Clinical significance and biological roles of CRKL in human bladder carcinoma.

CRKL encodes an adaptor protein that has been recently reported to be overexpressed in various cancers and associate with the malignant behavior of cancer cells. However, the expression pattern of CRKL protein and its clinical significance in human bladder cancer have not been well characterized to date. In the present study, CRKL expression was analyzed in 82 archived bladder cancer specimens using immunohistochemistry, and the correlations between CRKL expression and clinicopathological parameters were evaluated. We found that CRKL was overexpressed in 31 of 82 (37.8%) bladder cancer specimens. A significant association was observed between CRKL overexpression and tumor status (p = 0.019). To further explore the biological functions of CRKL in bladder cancer, we overexpressed CRKL in BIU-87 and 5637 cell lines. Using CCK8 assay and colony formation assay, we showed that CRKL upregulation increased cell proliferation. In addition, transwell assay showed that CRKL could also facilitate invasion. Further study demonstrated that CRKL upregulation increased cyclin D1 expression and ERK phosphorylation. In conclusion, CRKL is overexpressed in bladder cancer and regulates malignant cell growth and invasion, which makes CRKL a candidate therapeutic target for bladder cancer.

MicroRNA-17, 20a regulates the proangiogenic function of tumor-associated macrophages via targeting hypoxia-inducible factor 2α.

Tumor-associated macrophages (TAMs) constitute a major component of the leukocyte infiltrate of most solid tumors, and they usually exhibit a proangiogenic phenotype which facilitates tumor growth in most circumstances. However, the precise mechanisms regulating the proangiogenic properties of TAMs remain largely unclear. In the present study, we found that the expression of hypoxia-inducible factor 2α (HIF-2α) was significantly up-regulated in macrophages from tumor tissues of several solid tumors. Macrophages exposed to tumor cell line derived-culture supernatants (TSN) also expressed high levels of HIF-2α in vitro, without a requirement for hypoxia. We identified miR-17 and miR-20a as the key regulators of HIF-2α expression in TAMs, and autocrine IL-6 played an important role in mediating the expression of miR-17, miR-20a, and thereafter HIF-2α in TAMs. Furthermore, the elevated HIF-2α in TAMs stimulated transcription of a set of proangiogenic genes such as VEGFA and PDGFB, which might in turn contribute to the angiogenic process within tumors. Our data provide evidence in support of the critical role of HIF-2α in the proangiogenic activity of TAMs and also reveal a novel mechanism by which miRNAs regulate TAM functions through modulation of HIF-2α expression under non-hypoxic conditions.

Expression and biological roles of SATB1 in human bladder cancer.

Special AT-rich sequence-binding protein-1 (SATB1) has been recently reported to be overexpressed in various cancers and associate with the malignant behavior of cancer cells. However, the expression and potential roles of SATB1 in bladder cancer remains unclear. In the present study, SATB1 expression was analyzed in 85 archived bladder cancer specimens using immunohistochemistry and the correlations between SATB1 expression and clinicopathological parameters were evaluated. To further explore the biological functions of SATB1 in bladder cancer, siRNA knockdown was performed in 5637 and T24 bladder cancer cell lines. We then carried out CCK8 assay and examined cisplatin-induced apoptosis to address the roles of SATB1 in proliferation and apoptosis. We found that SATB1 was overexpressed in 33 of 85 (38.8 %) bladder cancer specimens. SATB1 overexpression associated with tumor grade (p = 0.002) and tumor stage (p = 0.027). SATB1 depletion in 5637 and T24 cells decreased cell proliferation while upregulating cisplatin-induced apoptosis. Further study demonstrated that SATB1 knockdown decreased cyclin D1 and cyclin E expression and upregulated caspase3 cleavage. In conclusion, SATB1 is overexpressed in bladder cancer and regulates malignant cell growth and apoptosis, which makes SATB1 a therapeutic target candidate for bladder cancer.

[Clinicopathologic analysis of spermatocytic seminoma].

OBJECTIVE: To study the clinicopathologic features and biological behavior of spermatocytic seminoma. METHODS: A retrospective analysis of patients diagnosed as seminoma, spermatocytic seminoma between January 2003 and May 2011, was performed. Clinical data, HE stained section and immunohistochemical staining (SP method) were reviewed with follow-up. RESULTS: Sixty-six cases of seminoma and 5 cases of spermatocytic seminoma were identified. The average age at the diagnosis of 5 cases of spermatocytic seminoma was 53 years, and no patient had a history of crytorchidism or germ cell tumor. All five patients had stage pT1 tumor. Immunohistochemical studies showed that spermatocytic seminoma was negative for CK, vimentin, OCT3/4, PLAP, and LCA, and PAS staining was also negative. All five patients were well after operation. In contrast, the average age at diagnosis of the 66 cases of seminoma was 37 years, in which 12% had a history of crytorchidism and 11% were in stage pT2 or the above. Immunohistochemical studies showed that seminoma was positive for OCT3/4, PLAP, and CD117. During the follow-up, 2 patients developed metastasis and 3 patients died of the disease. CONCLUSIONS: Spermatocytic seminoma is rare and appears to follow a benign clinical course Due to its favourable prognosis, further treatment is not necessary after orchidectomy. Accurate pathologic diagnosis is critical for patient management and for avoiding over-treatment.

Peritumoral neutrophils link inflammatory response to disease progression by fostering angiogenesis in hepatocellular carcinoma.

BACKGROUND & AIMS: Substantial evidence indicates that inflammation is a critical component of tumor progression. Hepatocellular carcinoma (HCC) is usually derived from inflamed cirrhotic liver with extensive leukocyte infiltration. Neutrophils are the common inflammatory infiltrate in tumors, but their nature and regulation in human cancers remain elusive. METHODS: A total of 238 HCC patients were enrolled randomly. Immunohistochemistry and SuperArray Real-Time PCR were used to analyze the distribution and clinical relevance of neutrophils in different microanatomical areas. The regulation and function of neutrophils were assessed by both in vitro and in vivo studies. RESULTS: Neutrophils were enriched predominantly in peritumoral stroma of HCC tissues and their levels could serve as a powerful predictor for poor survival in HCC patients. Proinflammatory IL-17 is a critical mediator of the recruitment of neutrophils into peritumoral stroma of HCC tissues by epithelial cell-derived CXC chemokines. The accumulated peritumoral neutrophils were the major source of matrix metalloproteinase-9 in HCC tissues; this secreted protein stimulated proangiogenic activity in hepatoma cells. Accordingly, high infiltration of peritumoral neutrophils was positively correlated with angiogenesis progression at tumor-invading edge of HCC patients. Furthermore, we found that selective depletion of neutrophils effectively inhibited tumor angiogenesis and growth, in vivo. CONCLUSIONS: These data provide direct evidence supporting the critical role of neutrophils in human tumor progression and reveal a fine-tuned collaborative action between cancer cells and immune cells in distinct tumor milieu, which reroutes the inflammatory response into a tumor-promoting direction.

MicroRNA-155 regulates inflammatory cytokine production in tumor-associated macrophages via targeting C/EBPbeta.

Macrophages (Mphi) are prominent components of solid tumors and exhibit distinct phenotypes in different microenvironments. We have recently found that tumors can alter the normal developmental process of Mphi to trigger transient activation of monocytes, but the underlying regulatory mechanisms are incompletely understood. Here, we showed that the protein expression of transcription factor C/EBPbeta was markedly elevated in tumor-associated Mphi both in vitro and human tumors in situ. The expression of C/EBP protein correlated with cytokine production in tumor-activated monocytes. Moreover, we found that C/EBPbeta expression was regulated at the post-transcriptional level and correlated with sustained reduction of microRNA-155 (miR-155) in tumor-activated monocytes. Bioinformatic analysis revealed that C/EBPbeta is a potential target of miR-155 and luciferase assay confirmed that C/EBPbeta translation is suppressed by miR-155 through interaction with the 3'UTR of C/EBPbeta mRNA. Further analysis showed that induction of miR-155 suppressed C/EBPbeta protein expression as well as cytokine production in tumor-activated monocytes, an effect which could be mimicked by silencing of C/EBPbeta. These results indicate that tumor environment causes a sustained reduction of miR-155 in monocytes/Mphi, which in turn regulates the functional activities of monocytes/Mphi by releasing the translational inhibition of transcription factor C/EBPbeta.