Cancer Nests Research Articles

Differential expression of microRNAs in colorectal cancer: Different patterns between isolated cancer gland and stromal cells.

Although microRNAs (miRNAs) play an important role in invasive tumor lesions, which involve cancer tissues mixed with stromal tissues, the differences in miRNA expression between cancer and stromal cells remain unclear. We selected 13 miRNAs and examined their differential expression patterns in cancer gland cells and surrounding stromal cells isolated from 24 colorectal cancer (CRC) specimens using a crypt isolation method. Although six miRNAs were upregulated in gland cells, only three were upregulated in the corresponding stromal cells, in the cancer compared with non-cancer specimens. Next, we examined the differences in miRNA expression between isolated cancer gland and stromal cells. Five miRNAs showed statistical differences in their cancer-related differential expression patterns between isolated cancer gland and stromal cells. We then compared these miRNA expression patterns in isolated cancer gland and stromal cells with those in fresh intact tumor tissues, consisting of cancer nests and stromal tissue, obtained from the 24 CRCs. The expression patterns of three miRNAs in the intact cancer tissue samples did not correspond with those in the isolated components. Identification of the expression patterns of miRNAs in both the cancer gland and stromal cell components of the tumor microenvironment greatly contributes to evaluating epigenetic regulation in CRC.

Long noncoding RNA CCAL transferred from fibroblasts by exosomes promotes chemoresistance of colorectal cancer cells.

Long noncoding RNAs (lncRNAs) are involved in the pathology of colorectal cancer (CRC). Current efforts to eradicate CRC predominantly focused on targeting the proliferation of rapidly growing cancer epithelial cells. This is largely ineffective with resistance arising in most tumors after exposure to chemotherapy. Despite the long-standing recognition of the crosstalk between carcinoma-associated fibroblasts (CAFs) and cancer cells in the tumor microenvironment, how CAFs may contribute to drug resistance in neighboring cancer cells is not well characterized. Here, we show that lncRNA CCAL (colorectal cancer-associated lncRNA) promotes oxaliplatin (Oxa) resistance of CRC cells. RNA-ISH shows higher CCAL expressed in the tumor stroma compared to cancer nests of CRC tissues. Functional studies reveal that CCAL is transferred from CAFs to the cancer cells via exosomes, where it suppresses CRC cell apoptosis, confers chemoresistance and activates β-catenin pathway in vitro and in vivo. Mechanistically, CCAL interacts directly with mRNA stabilizing protein HuR (human antigen R) to increase β-catenin mRNA and protein levels. Our findings indicate that CCAL expressed by CAFs of the colorectal tumor stroma contributes to tumor chemoresistance and CCAL may serve as a potential therapeutic target for Oxa resistance.

Imaging and Pathology Study of the Chemotherapy Regression Area of Hepatoblastoma – A Prospective Single-Center Study

Objective: The objective of this study is to determine the frequency of no residual cancer tissue in the chemotherapy regression area (CRA) of hepatoblastoma after preoperative chemotherapy and to measure the distance between the tumor capsule and the residual cancer nests. Methods: All the tissues in the CRAs of the resected specimens were excised. HE staining and immunohistochemical staining were performed to determine the frequency of residual cancer tissue in the CRA, and the distances between the residual cancer nests and the tumor capsule were measured. Results: A total of 30 patients were included in the study. The tumor volume decreased after chemotherapy by an average of 619 ml. Of the 30 patients, the CRAs of 18 still had residual cancer nests. The longest distance between the residual cancer nest and tumor capsule was 11.2 mm. Conclusions: After chemotherapy, 60% of patients still had residual cancer nests in CRAs, the furthest distance was 11.2 mm.

Reporter Cell Assessment of TLR4-Induced NF-κB Responses to Cell-Free Hemoglobin and the Influence of Biliverdin.

Hemoglobin (Hb) released during red blood cell lysis can initiate TLR4-dependent signaling and trigger NF-κB activation in surrounding cells. Observations of chronic bleeding in various cancers leads us to hypothesize that Hb and Hb degradation products released from lysed RBC near cancer nests might modulate local TLR4-positive cells. We addressed the hypothesis in vitro by measuring Hb- and biliverdin (Bv)-induced NF-κB signaling in an engineered human TLR4 reporter cell model (HEK-BlueTM hTLR4). Therein, TLR4 stimulation was assessed by measuring NF-κB-dependent secreted alkaline phosphatase (SEAP). hTLR4 reporter cells incubated with 8 ηM lipopolysaccharide (LPS) or 20-40 μM fungal mannoprotein (FM) produced significant amounts of SEAP. hTLR4 reporter cells also produced SEAP in response to human, but not porcine or bovine, Hb. HEK-Blue Null2TM reporter cells lacking TLR4 did not respond to LPS, FM, or Hb. Bv was non-stimulatory in reporter cells. When Bv was added to Hb-stimulated reporter cells, SEAP production was reduced by 95%, but when Bv was applied during LPS and FM stimulation, SEAP production was reduced by 33% and 27%, respectively. In conclusion, Hb initiated NF-κB signaling that was dependent upon TLR4 expression and that Bv can act as a TLR4 antagonist. Moreover, this study suggests that hemorrhage and extravascular hemolysis could provide competitive Hb and Bv signaling to nearby cells expressing TLR4, and that this process could modulate NF-κB signaling in TLR4-positive cancer cells and cancer-infiltrating leukocytes.

Analysis of the treg cell population in the peripheral blood of ovarian cancer patients in relation to the long-term outcomes.

There is growing evidence that Treg cell infiltration into the cancer nest is associated with poor prognosis. How- ever, the Treg cell population in the peripheral blood may change when a different type of anticancer therapy is applied. Since Treg cells may support tumor growth by enhancing the suppressive profile of the cancer microenvironment, the assessment of Treg cells can bring to light important information regarding prognosis. Thus we decided to analyze the Treg cell population in the peripheral blood in relation to long-term outcomes in the group of patients with ovarian cancer. The 80 patients included in the study were treated surgically followed by chemiotherapy for ovar- ian cancer between October 2010 through May 2011.The peripheral blood samples from the patients were collected directly prior to chemotherapy. Information on any patients who died was retrieved from the database of the Cuiavia-Pomerania Regional Office of the National Health System of Poland. CD4+CD25+FOXP3+ lymphocytes T were assed by flow cytometry. We have analyzed the long term outcomes of treatment regarding to the level of Treg cells in peripheral blood. We found that patients with serous adenocarcinomas had significantly higher Treg levels compared to those patients with non-serous types. Patients who had a higher percentage of Treg cells within the CD4+ cell population prior to the beginning of the treatment had worse long-term outcomes from the applied therapy. The assessment of Treg levels prior to the start of chemotherapy is clinically useful and may predict overall survival in ovarian cancer patients.

Aberrant expression and high-frequency mutations of SHARPIN in nonmelanoma skin cancer.

Squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) have exhibited a marked increase in incidence in previous decades and are the most common malignancies in Caucasian populations. Src homology 3 and multiple ankyrin repeat domains protein-associated RH domain-interacting protein (SHARPIN) has been identified as a commonly overexpressed proto-oncogene in several types of visceral cancer. However, to the best of our knowledge, the functions of SHARPIN in nonmelanoma skin cancer (NMSC) have not been described. The present study aimed to investigate the expression of SHARPIN protein and SHARPIN mutations in NMSC. A total of 85 BCC, 77 SCC and 21 keratoacanthoma (KA) formalin-fixed paraffin-embedded (FFPE) samples were collected. SHARPIN expression was detected using immunohistochemistry. DNA was extracted from the FFPE samples, and the sequences of SHARPIN were analyzed using polymerase chain reaction. In addition, high and moderate expression levels of SHARPIN were observed in normal skin tissues and KA samples. However, the expression of SHARPIN was absent in cancer nests and was significantly low in precancerous NMSC lesions. The total mutation frequency of SHARPIN was 21.8% in BCC and 17.0% in SCC. These data indicate that SHARPIN may serve a tumor-suppressing role and be a promising diagnostic, prognostic and therapeutic biomarker in NMSC.

Prediction of pathological margin status using preoperative contrast-enhanced MRI in patients with early breast cancer who underwent skin-sparing mastectomy

Skin-sparing mastectomy (SSM) with immediate reconstruction is standard surgical treatment for early breast cancer with widespread ductal carcinoma in situ (DCIS). The local recurrence rate after SSM is up to 7.0%. We investigated prediction of the pathological margin using contrast-enhanced MRI, and evaluated the cut-off point to obtain the safety margin. We performed SSM with immediate reconstruction in 216 early breast cancer patients with widespread DCIS and/or invasive cancer from January 2014 to December 2015. Forty cases were retrospectively reviewed after excluding those with >15mm between skin and tumor, determined by preoperative contrast-enhanced MRI, or involving reconstructive surgery for local recurrence, immeasurable lesion by preoperative contrast-enhanced MRI, or neoadjuvant chemotherapy. We defined a positive pathological margin as <1mm from the cancer nest. We reviewed the distance between skin and tumor by MRI and pathological examination. To identify the cut-off for predicting a positive pathological margin, we performed sensitivity analysis using an ROC curve. The margin-positive rate by pathological examination was 27.5% (n=11/40), with a moderate correlation of MRI margin and pathological margin (r=0.44). The best cut-off point for margin positivity was 5mm of MRI margin, with sensitivity and specificity of 54% and 86%, respectively (P=0.009). This is the first prediction of pathological margin by preoperative contrast-enhanced MRI in early breast cancer patients with SSM. Care is required for SSM if the MRI margin is less than 5mm due to pathological margin positivity.

CK7 expression associates with the location, differentiation, lymph node metastasis, and the Dukes' stage of primary colorectal cancers.

Purpose: Most colorectal cancers (CRCs) show positive immunohistochemical (IHC) staining for CK20 and negative staining for CK7. However, in clinical settings, some CRCs show positive IHC staining for CK7, and the clinicopathological significance of this needs to be studied. This study investigated the clinicopathological significance of CK7 positivity in CRCs.Materials and Methods: A total of 178 patients with CRC were used to study the clinicopathological significance of CK7 positivity. Western blotting and immunocytochemical (ICC) staining were used to compare the expression levels of CK7 before and after CoCl2 treatment.Results: CK7 expression was associated with the location, differentiation, lymph node metastasis, and the Dukes' stage of CRCs. CK7 positive cells were mainly distributed at the edge of cancer nests, at the invasion front, as single stromal polyploid giant cancer cells (PGCCs), in tumor buds, in intravascular tumor emboli, and in a micropapillary pattern. Results of ICC staining showed that CK7 expression was almost negative in LoVo and HCT116 before CoCl2 treatment. After CoCl2 treatment, the PGCCs and their daughter cells of LoVo and HCT116 yielded positive results in CK7 ICC staining. Results of western blotting also confirmed that there was higher CK7 expression in LoVo and HCT116 after CoCl2 treatment than in the control.Conclusion: CRC cells expressing CK7 may have strong invasive and metastatic abilities. Some metastasis-related morphological characteristics in CRCs including the invasion front, micropapillary pattern, tumor emboli, and single stromal PGCCs associated with CK7 positive expression.

High CD169 expression in lymph node macrophages predicts a favorable clinical course in patients with esophageal cancer.

Recent findings indicate CD169-positive lymph node sinus macrophages (LySMs) in the regional lymph nodes (RLNs) play an important role in anti-cancer immunity. In the present study, we investigated the correlation between CD169 expression in RLNs and clinicopathologic factors. Higher CD169 expression in LySMs was significantly associated with longer cancer-specific survival (CSS). The density of tumor-infiltrating lymphocytes (TILs) in the cancer nest and CD169 expression on LySMs were positively associated in patients who underwent pretreatment. As CD169 expression is thought to reflect a high interferon signature in RLNs, we tried to identify immunity-related genes that are up-regulated by interferon in macrophages as well as CD169. Indoleamine 2,3-dioxygenase (IDO1) was found to be elevated by interferon, and expression of IDO1 was tested using immunohistochemistry. IDO1 expression on LySMs was positively correlated with CD169 expression; however, there was no significant correlation between IDO1 and clinicopathologic factors. These results suggest that high expression of CD169 in LySMs reflects a high potential for anti-cancer immune responses in esophageal cancer patients and that monitoring CD169 expression would be useful for evaluating the potential of anti-cancer immune reactions.

The analysis of human leukocyte antigen-G level in patients with endometrial cancer by Western blot technique.

Aberrant expression of human leukocyte antigen-G (HLA-G) in various malignancies has been shown to participate in tumour development by suppressing immune regulation within the tumour microenvironment. The detection of HLA-G has reportedly been correlated with certain clinicopathological parameters in several neoplasms. Both the soluble and membranous forms of HLA-G are biologically active, and therefore, we aimed to evaluate the HLA-G level by Western blot technique. The total amount of HLA-G protein was analyzed in the primary tumour in 113 tissue samples derived from patients with endometrial cancer. The HLA-G protein level was measured by Western Blot technique and was analyzed with respect to the clinicopathological parameters. Human leukocyte antigen-G protein levels were statistically significantly higher in the cancerous tissues derived from the women with advanced endometrial cancer than those from women with early stage disease. Moreover, we showed that endometrial cancer patients with lymph node metastases had statistically significantly higher HLA-G levels in the primary uterine tumour. The aberrant expression of HLA-G antigens by malignant cells could be one of the strategies tumour cells use to escape immune surveillance. The presence of HLA-G within the cancer nest and its microenvironment would seem to be linked to disease progression.

Immune Microenvironment Differences Between Squamous and Non-squamous Non–small-cell Lung Cancer and Their Influence on the Prognosis

IntroductionCheckpoint blockades have entered routine clinical use for non–small-cell lung cancer (NSCLC). However, there were some differences in efficacy and response predictors for anti-programmed cell death protein 1 (PD-1) antibodies between squamous (SQ) and nonsquamous (non-SQ) NSCLC. The study aims to elucidate the possible difference in immune microenvironment between SQ-NSCLC and non-SQ-NSCLC and their influence on the prognosis. Patients and MethodsA total of 197 patients with stages I to III NSCLC were included. cluster of differentiation 8 (CD8), cluster of differentiation 4 (CD4), transcription factor forkhead box P3 (FOXP3), and programmed death-ligand 1 (PD-L1) expression were examined in cancer nest and stroma on 85 SQ-NSCLC and 112 non-SQ-NSCLC samples using immunohistochemistry. ResultsMore CD8+ tumor infiltrating lymphocytes (TILs) were detected in the cancer nests (cCD8) from patients with SQ-NSCLC than those with non-SQ-NSCLC (56% vs. 34%; P = .002). There were no significant differences between the SQ and non-SQ groups in terms of other TIL markers or PD-L1 expression. Multivariate analysis showed that the degree of cCD8+ TIL infiltration was an independent positive predictor for overall survival (OS) in the SQ-NSCLC group (P = .003) and in the non-SQ-NSCLC group (P = .024). In the univariate analysis, CD8+ TILs in the stroma, CD4+ TILs in the cancer nest and stroma, and FOXP3+ TILs in the cancer stroma associated with different prognoses for patients with either non-SQ-NSCLC or SQ-NSCLC. Using a 10% cutoff, PD-L1 expression was a poor prognostic factor in total NSCLC (P = .011), stage I (P = .037), SQ-NSCLC (P = .097), and non-SQ-NSCLC (P = .051). ConclusionThe different cCD8+ TIL profile and different prognostic value with certain TILs indicates that SQ-NSCLC and non-SQ-NSCLC are likely different cancer types with respect to their immune microenvironments.

Epstein-Barr virus positivity among surgically resected intramucosal gastric cancer.

Epstein-Barr virus-associated gastric cancer (EBV-GC) accounts for approximately 8% of gastric cancers. However, little is known regarding intramucosal EBV-GC. The present study aimed to evaluate endoscopic and clinicopathological characteristics of intramucosal EBV-GC. Pathological data of 172 patients with 173 intramucosal gastric cancers who received gastrectomy with lymph node dissection were obtained for review. EBV-encoded small RNA in situ hybridization (EBER-ISH) was carried out using a tissue microarray block. Eight intramucosal early gastric cancers (4.6%) were EBER-ISH positive in which no cases had any lymph node metastasis. Macroscopic types were either depressed or flat, dominant histology was mixed type of moderate and poorly differentiated adenocarcinoma. In detail, histological features of "lace pattern" or "lymphocyte infiltration into the stroma or cancer nests" were observed.

Occurrence of Occult Malignancies in Reduction Mammoplasties.

ObjectivesPatients undergoing reduction mammoplasty (RM) bear the risk of having occult breast cancer nests. The detection rate of malignant neoplasms in the resected specimens, varies greatly in the literature. The aim of our present study was to analyze risk factors and evaluate histopathological findings in our cohort of patients who underwent RM towards our center.Material and methodsIn this retrospective single center study we analyzed 559 female patients [median age 35.99 (±13.34)] who underwent RM between 2000 and 2010. The presence of carcinoma and ductal- (DCIS) or lobular carcinoma in situ (LCIS) were considered as pathological findings. Body mass index (BMI), age, surgical technique and mass of resected tissue were included into the analysis.ResultsThere were 6 cases of occult neoplasia (1.08 %) including 2 cases of breast cancer, one multicentric DCIS and 3 cases of LCIS (0.54 %) in 559 patients. Patients with breast cancer showed a significant increased median age: 49y median (IQR ± 18) vs. 35y (IQR ± 21) (p = 0.004) and a trend towards increased BMI: 25.88 median (IQR ± 7.3) vs. 24.50 (IQR ± 4.09) (p = 0.219), compared to patients without pathological results. One patient with occult carcinoma had a negative preoperative mammography, a patient with LCIS a negative preoperative breast ultrasound.ConclusionsIn our study the occurrence of occult neoplasia was associated with increased age and showed a trend towards increased BMI when compared to patients without pathological findings. The study demonstrates the necessity of thorough medical history, preoperative diagnostic screening and histopathological analysis of all resected specimens.

The Heterogeneity Between Lynch-Associated and Sporadic MMR Deficiency in Colorectal Cancers.

Previous studies demonstrated that prognosis of germline deficiency in mismatch repair protein (dMMR) was different from that of sporadic dMMR. The underlying mechanism has not been studied. From a prospectively maintained database, we collected dMMR colorectal cancer (CRC) patients identified by postoperative immunohistochemistry screening. According to genetic test, patients were grouped as Lynch-associated or sporadic dMMR. We compared the clinical-pathological features, prognosis, and immunoreactive differences between the two groups. By whole-exome sequencing and neoantigen detection pipeline, mutational frequencies and neoantigen burdens were also compared. All statistical tests were two-sided. Sixty-seven sporadic dMMR and 85 Lynch-associated CRC patients were included in the study. Sporadic dMMR patients were older (P < .001) and their tumors were poorly differentiated (P = .03). The survival was better in the Lynch-associated group (P = .001). After adjustment, the difference still remained statistically significant (hazard ratio = 0.29, 95% confidence interval = 0.09 to 0.95, P = .04). The scores of Crohn's-like reaction (CRO; P < .001), immunoreactions in the invasive margin (IM; P = .01), tumor stroma (TS; P = .009), and cancer nest (CN; P = .02) of the Lynch-associated group were statistically significantly higher. The numbers of CD3+, CD8+, Foxp3+ tumor-infiltrating lymphocytes (TILs) in IM; CD3+, CD4+ TILs in TS; and CD3+, CD4+, CD8+ TILs in CN were statistically significantly higher in Lynch-associated dMMR patients. Based on the 16 patients who under went whole-exome sequencing, there were also more somatic mutations and neoantigen burdens in the Lynch-associated group compared with the sporadic dMMR group (439/pt vs 68/pt, P = .006; 628/pt vs 97/pt, P = .009). There are heterogeneities in dMMR CRCs. Lynch-associated dMMR patients present with more somatic mutations and neoantigens compared with sporadic dMMR, which probably results in stronger immunoreactions and survival improvement.

The relationship between right-sided tumour location, tumour microenvironment, systemic inflammation, adjuvant therapy and survival in patients undergoing surgery for colon and rectal cancer

Background:There has been an increasing interest in the role of tumour location in the treatment and prognosis of patients with colorectal cancer (CRC), specifically in the adjuvant setting. Together with genomic data, this has led to the proposal that right-sided and left-sided tumours should be considered as distinct biological and clinical entities. The aim of the present study was to examine the relationship between tumour location, tumour microenvironment, systemic inflammatory response (SIR), adjuvant chemotherapy and survival in patients undergoing potentially curative surgery for stage I–III colon and rectal cancer.Methods:Clinicopathological characteristics were extracted from a prospective database. MMR and BRAF status was determined using immunohistochemistry. The tumour microenvironment was assessed using routine H&E pathological sections. SIR was assessed using modified Glasgow Prognostic Score (mGPS), neutrophil:lymphocyte ratio (NLR), neutrophil:platelet score (NPS) and lymphocyte:monocyte ratio (LMR).Results:Overall, 972 patients were included. The majority were over 65 years (68%), male (55%), TNM stage II/III (82%). In all, 40% of patients had right-sided tumours and 31% had rectal cancers. Right-sided tumour location was associated with older age (P=0.001), deficient MMR (P=0.005), higher T stage (P<0.001), poor tumour differentiation (P<0.001), venous invasion (P=0.021), and high CD3+ within cancer cell nests (P=0.048). Right-sided location was consistently associated with a high SIR, mGPS (P<0.001) and NPS (P<0.001). There was no relationship between tumour location, adjuvant chemotherapy (P=0.632) or cancer-specific survival (CSS; P=0.377). In those 275 patients who received adjuvant chemotherapy, right-sided location was not associated with the MMR status (P=0.509) but was associated with higher T stage (P=0.001), venous invasion (P=0.036), CD3+ at the invasive margin (P=0.033) and CD3+ within cancer nests (P=0.012). There was no relationship between tumour location, SIR or CSS in the adjuvant group.Conclusions:Right-sided tumour location was associated with an elevated tumour lymphocytic infiltrate and an elevated SIR. There was no association between tumour location and survival in the non-adjuvant or adjuvant setting in patients undergoing potentially curative surgery for stage I–III colon and rectal cancer.

Carcinoma-associated fibroblasts promote the stemness and chemoresistance of colorectal cancer by transferring exosomal lncRNA H19.

Long non-coding RNAs (lncRNAs) are involved in the pathology of various tumors, including colorectal cancer (CRC). The crosstalk between carcinoma- associated fibroblasts (CAFs) and cancer cells in the tumor microenvironment promotes tumor development and confers chemoresistance. In this study, we further investigated the underlying tumor-promoting roles of CAFs and the molecular mediators involved in these processes.Methods: The AOM/DSS-induced colitis-associated cancer (CAC) mouse model was established, and RNA sequencing was performed. Small interfering RNA (siRNA) sequences were used to knock down H19. Cell apoptosis was measured by flow cytometry. SW480 cells with H19 stably knocked down were used to establish a xenograft model. The indicated protein levels in xenograft tumor tissues were confirmed by immunohistochemistry assay, and cell apoptosis was analyzed by TUNEL apoptosis assay. RNA-FISH and immunofluorescence assays were performed to assess the expression of H19 in tumor stroma and cancer nests. The AldeRed ALDH detection assay was performed to detect intracellular aldehyde dehydrogenase (ALDH) enzyme activity. Isolated exosomes were identified by transmission electron microscopy, nanoparticle tracking and Western blotting.Results: H19 was highly expressed in the tumor tissues of CAC mice compared with the expression in normal colon tissues. The up-regulation of H19 was also confirmed in CRC patient samples at different tumor node metastasis (TNM) stages. Moreover, H19 was associated with the stemness of colorectal cancer stem cells (CSCs) in CRC specimens. H19 promoted the stemness of CSCs and increased the frequency of tumor-initiating cells. RNA-FISH showed higher expression of H19 in tumor stroma than in cancer nests. Of note, H19 was enriched in CAF-derived conditioned medium and exosomes, which in turn promoted the stemness of CSCs and the chemoresistance of CRC cells in vitro and in vivo. Furthermore, H19 activated the β-catenin pathway via acting as a competing endogenous RNA sponge for miR-141 in CRC, while miR-141 significantly inhibited the stemness of CRC cells.Conclusion: CAFs promote the stemness and chemoresistance of CRC by transferring exosomal H19. H19 activated the β-catenin pathway via acting as a competing endogenous RNA sponge for miR-141, while miR-141 inhibited the stemness of CRC cells. Our findings indicate that H19 expressed by CAFs of the colorectal tumor stroma contributes to tumor development and chemoresistance.

Stromal mesenchymal stem cells facilitate pancreatic cancer progression by regulating specific secretory molecules through mutual cellular interaction.

Pancreatic ductal adenocarcinoma (PDAC) is currently one of the most intractable malignancies with a typical scirrhous pattern in histology. Due to its abundant tumor stroma and scant vascularization, chemotherapeutic agents are considered inefficiently permeable to cancer nests, making it highly difficult to cure the patients with PDAC. However, PDAC is also considered to owe its intractability to other critical factors such as cellular interaction between tumor cells and tumor microenvironment as well as architectural barriers, which increases in therapeutic resistance. Here, we report a specific cellular interaction between PDAC cells and mesenchymal stem cells (MSCs) intermingled in PDAC stroma, which facilitates cancer invasion. Secretory phenotype profiling revealed that production of Amphiregulin (AREG) and MMP-3 were specifically upregulated under the coexistence of BxPC3 cells with human MSCs (approximately four to ten folds in AREG, and twenty to sixty-folds in MMP-3 compared to that of BxPC3 cells alone), whereas MMP-9 expression was decreased (less than one-tenth comparing with that of BxPC3 cells alone). Blockage of AREG production by its specific siRNA removed MSC-mediated driving force of BxPC3 invasiveness. Immunohistochemical analysis of tissue samples obtained both from PDAC patients and PDAC imitating mouse xenografted models revealed that significant coexpression of AREG and its receptor EGFR were detected on the cancer cells at invasive front. These results strongly suggested that cellular interaction between cancer cells and MSCs in the PDAC stroma might be critical to cancer progression, especially in the process of local invasion and the early stage development of metastasis.

Synthesis and Investigation of Photophysical and Biological Properties of Novel S-Containing Bacteriopurpurinimides.

Novel hybrid molecule containing 2-mercaptoethylamine was synthesized starting from O-propyloxime-N-propoxy bacteriopurpurinimide (dipropoxy-BPI), which was readily oxidized in oxygen atmosphere yielding the corresponding disulfide analogue (disulfide-BPI). Spectral, photophysical, photodynamic, and biological properties of compound were properly evaluated. Compounds bearing disulfide moiety can directly interact with glutathione (GSH), thereby reducing its intracellular concentration. Indeed, mice sarcoma S37 cell line was treated in vitro with disulfide-BPI, yielding a CC50 value of 0.05 ± 0.005 μM. A relatively high level of singlet oxygen was detected. It was demonstrated (by fluorescence) that the PS was rapidly accumulated in a cancer nest (S37) at a relatively high level after 2 h upon intravenous administration. After 24 h, no traces of the molecule were detected in the tumor mass. Moreover, high photodynamic efficiency was demonstrated at doses of 150-300 J/cm2 against two different in vivo tumor models, achieving 100% regression of cancer growth.

The new developments of carcinoma nest in the research of tumor metastasis

Malignant tumors constitute an enormous burden on society in more and less economically developed countries alike. The occurrence of malignant tumors is increasing along with the aging of the population and lifestyle changes. Every year, 8.2 million patients died of malignant tumors in worldwide, in which about 90% patients died of malignant tumors associated organ metastasis. The formation of cancer nest is a key event in tumor metastasis and the present paper summaries the new development of malignant tumor metastasis research based on the classical theory and provides an even deeper understanding of tumor metastasis. Key words: Malignant tumor; Metastasis; Carcinoma nest

Distribution pattern of tumor associated macrophages predicts the prognosis of gastric cancer.

PurposeAs mayor biomarkers in tumor microenvironment (TME), tumor associated macrophages (TAMs) of gastric cancer (GC) still needs further studies in terms of the number and distribution pattern.MethodsHerein, tissue microarrays (TMA) incorporating 494 GC surgical samples in duplicate were stained for TAMs infiltration analysis. TAMs number was counted according to the locations, including infiltrating macrophages in cancer nest (MC), in invasive front (MF) and in stroma (MS). Correlations between TAMs number, distribution pattern and clinic-pathological features and survival analyses were performed.ResultsInfiltrating macrophages number in GC tissues was much higher than that in peritumoral tissues. TAMs number was not significantly correlated with the overall survival (OS). TAMs distribution pattern could be categorized into MC or MF/MS dominant pattern, and correlated with histological grade (P =0.001). The median OS of MF/MS dominant pattern (22.1, 95%CI: 23.5-28.9) was significantly shorter than that of MC dominant pattern (25.6, 95%CI: 28.5-35.6) (P =0.002). By receiver operating characteristic curve (ROC) analysis, the predictive value of TAMs distribution pattern was superior to histological grade and pM stage, but inferior to pN and TNM stage.ConclusionsTAMs distribution pattern could be an independent prognostic factor for the OS of GC patients, and patients with MF/MS dominant pattern had worse outcomes.