New horizons in tumor microenvironment biology: challenges and opportunities

The tumor microenvironment (TME) is being increasingly recognized as a key factor in multiple stages of disease progression, particularly local resistance, immune-escaping, and distant metastasis, thereby substantially impacting the future development of frontline interventions in clinical oncology. An appropriate understanding of the TME promotes evaluation and selection of candidate agents to control malignancies at both the primary sites as well as the metastatic settings. This review presents a timely outline of research advances in TME biology and highlights the prospect of targeting the TME as a critical strategy to overcome acquired resistance, prevent metastasis, and improve therapeutic efficacy. As benign cells in TME niches actively modulate response of cancer cells to a broad range of standard chemotherapies and targeted agents, cancer-oriented therapeutics should be combined with TME-targeting treatments to achieve optimal clinical outcomes. Overall, a body of updated information is delivered to summarize recently emerging and rapidly progressing aspects of TME studies, and to provide a significant guideline for prospective development of personalized medicine, with the long term aim of providing a cure for cancer patients.

Knockdown of long non-coding RNA HOTAIR suppresses tumor invasion and reverses epithelial-mesenchymal transition in gastric cancer

BACKGROUND

Over-expression of long non-coding RNA HOTAIR has been reported in several types of cancer. Yet its involvement in gastric cancer (GC) has not been well understood. The aim of present study was to examine the expression pattern of HOTAIR in GC patients, then, explore its role in promoting cancer invasion and underlying molecular mechanism.

METHODS

The expression level of HOTAIR in the tumor specimens of GC patients was quantified by Realtime RT-PCR. The correlation between HOTAIR level and clinicopathological factors as well as prognosis was then examined. Down-regulation of HOTAIR by RNA interference was applied to investigate its roles in tumor invasiveness via the view of Epithelial-to-mesenchymal transition (EMT).

RESULTS

The expression level of HOTAIR in cancer tissues was higher than that in adjacent noncancerous tissues. Expression level of HOTAIR was significantly correlated with lymph node metastasis and TNM stage. Furthermore, high expression level of HOTAIR was a predictor of poor over-all survival in GC patients. In vitro, inhibition of HOTAIR in GC cells could reduce invasiveness, as well as the expression of MMP1 and MMP3. In addition, suppression of HOTAIR could reverse EMT process.

CONCLUSIONS

HOTAIR could act as a potential predictor for over-all survival in patients with GC. Inhibition of HOTAIR could reduce invasiveness and reverse EMT process in GC cells, indicating the potential role of HOTAIR in GC diagnostics and therapeutics.

Phylogenetic distinction of iNOS and IDO function in mesenchymal stem cell-mediated immunosuppression in mammalian species

Mammalian mesenchymal stem cells (MSCs) have been shown to be strongly immunosuppressive in both animal disease models and human clinical trials. We have reported that the key molecule mediating immunosuppression by MSCs is species dependent: indoleamine 2,3-dioxygenase (IDO) in human and inducible nitric oxide synthase (iNOS) in mouse. In the present study, we isolated MSCs from several mammalian species, each of a different genus, and investigated the involvement of IDO and iNOS during MSC-mediated immunosuppression. The characterization of MSCs from different species was by adherence to tissue culture plastic, morphology, specific marker expression, and differentiation potential. On the basis of the inducibility of IDO and iNOS by inflammatory cytokines in MSCs, the tested mammalian species fall into two distinct groups: IDO utilizers and iNOS utilizers. MSCs from monkey, pig, and human employ IDO to suppress immune responses, whereas MSCs from mouse, rat, rabbit, and hamster utilize iNOS. Interestingly, based on the limited number of species tested, the iNOS-utilizing species all belong to the phylogenetic clade, Glires. Although the evolutionary significance of this divergence is not known, we believe that this study provides critical guidance for choosing appropriate animal models for preclinical studies of MSCs.

TNFα-activated mesenchymal stromal cells promote breast cancer metastasis by recruiting CXCR2+ neutrophils

Mesenchymal stromal cells (MSCs) tend to infiltrate into tumors and form a major component of the tumor microenvironment. Our previous work demonstrated that tumor necrosis factor α (TNFα)-activated MSCs significantly promoted tumor growth. However, the role of TNFα-treated MSCs in tumor metastasis remains elusive. Employing a lung metastasis model of murine breast cancer, we found that TNFα-activated MSCs strikingly enhanced tumor metastasis compared with normal MSCs. We analyzed the chemokine profiles and found that the expression of CCL5, CCR2 and CXCR2 ligands were enhanced in TNFα-activated MSCs. Using genetic or pharmacological strategies to inhibit CCL5 or CCR2, we demonstrated that CCL5 and CCR2 ligands were indispensable in supporting TNFα-activated MSCs to promote tumor metastasis. Analysis of immune cells revealed that CXCR2 ligands (CXCL1, CXCL 2 and CXCL5) expressed by TNFα-activated MSCs efficiently recruited CXCR2+ neutrophils into tumor. These neutrophils were responsible for the pro-metastatic effect of MSCs since inhibition of this chemotaxis abolished increased neutrophil recruitment and tumor metastasis. The interaction between neutrophils and tumor cells resulted in markedly elevated metastasis-related genes by tumor cells, including CXCR4, CXCR7, MMP12, MMP13, IL-6 and TGFβ. Importantly, in IL8high human breast cancer samples, we also observed similar alterations of gene expression. Collectively, our findings demonstrate that TNFα-activated MSCs promote tumor metastasis via CXCR2+ neutrophil recruitment.

Solid pseudopapillary tumor of the pancreas: a review of 553 cases in Chinese literature

AIM

To sum up the clinical and pathological characteristics of solid pseudopapillary tumor (SPT) and the experience with it.

METHODS

A total of 553 SPT patients reported in Chinese literature between January 1996 and January 2009 were retrospectively reviewed and analyzed.

RESULTS

The mean age of the 553 SPT patients included in this review was 27.2 years, and the male to female ratio was 1:8.37. Their symptoms were non-specific, and nearly one third of the patients were asymptomatic. Computed tomography and ultrasonography were performed to show the nature and location of SPT. Most of the tumors were distributed in the pancreatic head (39.8%), tail (24.1%), body and tail (19.5%). Forty-five patients (9.2%) were diagnosed as malignant SPT with metastasis or invasion. None of the clinical factors was closely related to the malignant potential of SPT. Surgery was the main therapeutic modality for SPT. Local resection, distal pancreatectomy and pancreatoduodenectomy were the most common surgical procedures. Local recurrence and hepatic metastasis were found in 11 and 2 patients, respectively, after radical resection. Four patients died of tumor progression within 4 years after palliative resection of SPT. The prognosis of SPT patients was good with a 5-year survival rate of 96.9%.

CONCLUSION

SPT of the pancreas is a rare indolent neoplasm that typically occurs in young females. It is a low-grade malignancy and can be cured with extended resection. The prognosis of such patients is good although the tumor may recur and metastasize.

TGF-β promotes immune responses in the presence of mesenchymal stem cells

Mesenchymal stem cells (MSCs) possess potent immunosuppression capacity and could exert strong therapeutic effects in many diseases, especially inflammatory disorders, in animal models and clinical settings. Although inflammatory cytokines are critical in inducing the immune modulatory properties of MSCs, detailed molecular mechanisms are yet to be fully understood. TGF-β is a well-known anti-inflammatory cytokine and exists in various inflammatory processes; therefore, we investigated whether it could synergize with MSCs in suppressing immune responses. To our surprise, we found that TGF-β actually reversed the immunosuppressive effect of MSCs on anti-CD3 activated splenocytes. Using TGF-β unresponsive MSCs, we demonstrated that the TGF-β directly acted on MSCs. Furthermore, we showed that the effect of TGF-β is exerted through inhibiting inflammatory cytokines induced inducible NO synthase (iNOS) expression in a SMAD3-dependent manner. Interestingly, we found that TGF-β produced by MSCs could act in an autocrine manner to reduce inflammatory cytokine-induced inducible NO synthase expression by MSCs themselves. Therefore, our study revealed a previously unrecognized property of TGF-β in promoting immune responses in the presence of MSCs.

5-Fluorouracil chemotherapy of gastric cancer generates residual cells with properties of cancer stem cells

BACKGROUND

5-Fluorouracil (5Fu) chemotherapy is the first treatment of choice for advanced gastric cancer (GC), but its effectiveness is limited by drug resistance. Emerging evidence suggests that the existence of cancer stem cells (CSCs) contributes to chemoresistance. The aim of the present study was to determine whether 5Fu chemotherapy generates residual cells with CSC-like properties in GC.

METHODS

Human GC cell lines, SGC7901 and AGS, were exposed to increasing 5Fu concentrations. The residual cells were assessed for both chemosensitivity and CSC-like properties. B lymphoma Mo-MLV insertion region 1 (BMI1), a putative CSC protein, was analyzed by immunohistochemical staining and subjected to pairwise comparison in GC tissues treated with or without neoadjuvant 5Fu-based chemotherapy. The correlation between BMI1 expression and recurrence-free survival in GC patients who received 5Fu-based neoadjuvant chemotherapy was then examined.

RESULTS

The residual cells exhibited 5Fu chemoresistance. These 5Fu-resistant cells displayed some CSC features, such as a high percentage of quiescent cells, increased self-renewal ability and tumorigenicity. The 5Fu-resistant cells were also enriched with cells expressing cluster of differentiation (CD)133+, CD326+ and CD44+CD24-. Moreover, the BMI1 gene was overexpressed in 5Fu-resistant cells, and BMI1 knockdown effectively reversed chemoresistance. The BMI1 protein was highly expressed consistently in the remaining GC tissues after 5Fu-based neoadjuvant chemotherapy, and BMI1 levels were correlated positively with recurrence-free survival in GC patients who received 5Fu-based neoadjuvant chemotherapy.

CONCLUSIONS

Our data provided molecular evidence illustrating that 5Fu chemotherapy in GC resulted in acquisition of CSC-like properties. Moreover, enhanced BMI1 expression contributed to 5Fu resistance and may serve as a potential therapeutic target to reverse chemoresistance in GC patients.

miR-155 regulates immune modulatory properties of mesenchymal stem cells by targeting TAK1-binding protein 2

MSCs possess potent immunosuppressive capacity. We have reported that mouse MSCs inhibit T cell proliferation and function via nitric oxide. This immune regulatory capacity of MSCs is induced by the inflammatory cytokines IFNγ together with either TNFα or IL-1β. This effect of inflammatory cytokines on MSCs is extraordinary; logarithmic increases in the expression of iNOS and chemokines are often observed. To investigate the molecular mechanisms underlying this robust effect of cytokines, we examined the expression of microRNAs in MSCs before and after cytokine treatment. We found that miR-155 is most significantly up-regulated. Furthermore, our results showed that miR-155 inhibits the immunosuppressive capacity of MSCs by reducing iNOS expression. We further demonstrated that miR-155 targets TAK1-binding protein 2 (TAB2) to regulate iNOS expression. Additionally, knockdown of TAB2 reduced iNOS expression. In summary, our study demonstrated that miR-155 inhibits the immunosuppressive capacity of MSCs by reducing iNOS expression by targeting TAB2. Our data revealed a novel role of miR-155 in regulating the immune modulatory activities of MSCs.

Downregulation of CXCL12 in mesenchymal stromal cells by TGFβ promotes breast cancer metastasis

Mesenchymal stromal cells (MSCs) are one of major components of the tumour microenvironment. Recent studies have shown that MSC tumour residence and their close interactions with inflammatory factors are important factors that affect tumour progression. Among tumour-associated inflammatory factors, transforming growth factor β (TGFβ) is regarded as a key determinant of malignancy. By employing a lung metastasis model of a murine breast cancer, we show here that the prometastatic effect of MSCs was dependent on their response to TGFβ. Interestingly, we found that MSC-produced CXCL12, an important chemokine in tumour metastasis, was markedly inhibited by TGFβ. Furthermore, silencing of CXCL12 in TGFβ-unresponsive MSCs restored their ability to promote tumour metastasis. We found that 4T1 breast cancer cells expressed high levels of CXCR7, but not of CXCR4, both of which are CXCL12 receptors. In presence of CXCL12, CXCR7 expression on tumour cells was decreased. Indeed, when CXCR7 was silenced in breast cancer cells, their metastatic ability was inhibited. Therefore, our data demonstrated that sustained expression of CXCL12 by MSCs in the primary tumour site inhibits metastasis through reduction of CXCR7, while, in the presence of TGFβ, this CXCL12 effect of MSCs on tumour cells is relieved. Importantly, elevated CXCR7 and depressed CXCL12 expression levels were prominent features of clinical breast cancer lesions and were related significantly with poor survival. Our findings reveal a novel mechanism of MSC effects on malignant cells through which crosstalk between MSCs and TGFβ regulates tumour metastasis.

Tumour cell-derived exosomes endow mesenchymal stromal cells with tumour-promotion capabilities

Mesenchymal stromal cells (MSCs) are a major component of the tumour microenvironment. A plethora of elegant studies focusing on tumour-derived MSCs have shown that they, unlike normal MSCs in other tissue, exhibit a strong ability to promote tumour progression. However, the mechanisms underlying the conversion of normal MSCs into tumour-associated MSCs are unknown. We report here a critical role of tumour cell-derived exosomes in endowing bone marrow-derived MSCs (BM-MSCs) with a tumour-favourable phenotype. Tumour cell-derived exosomes affected neither the growth factor production nor the immunosuppressive property of MSCs; rather, they endowed MSCs with a strong ability to promote macrophage infiltration into B16-F0 melanoma or EL-4 lymphoma. Ablation of macrophages by clodronate liposome administration reversed the tumour-promoting effect of MSCs educated by tumour cell-derived exosomes (TE-MSCs) on the tumour growth. By comparing the chemokine profile of BM-MSCs with that of TE-MSCs, we found that TE-MSCs produced a large amount of CCR2 ligands, CCL2 and CCL7, which are responsible for macrophage recruitment. CCR2-specific inhibitor was found to block the tumour-promoting effect of TE-MSCs. Thus, our investigations demonstrated that tumour cell-derived exosomes confer BM-MSCs the ability to enhance tumour growth. Therefore, we uncovered a novel mechanism underlying the conversion of normal MSCs to tumour-associated MSCs.

p53 regulates mesenchymal stem cell-mediated tumor suppression in a tumor microenvironment through immune modulation

p53 is one of the most studied genes in cancer biology, and mutations in this gene may be predictive for the development of many types of cancer in humans and in animals. However, whether p53 mutations in non-tumor stromal cells can affect tumor development has received very little attention. In this study, we show that B16F0 melanoma cells form much larger tumors in p53-deficient mice than in wild-type mice, indicating a potential role of p53 deficiency in non-tumor cells of the microenvironment. As mesenchymal stem cells (MSCs) are attracted to tumors and form a major component of the tumor microenvironment, we examined the potential role of p53 status in MSCs in tumor development. We found that larger tumors resulted when B16F0 melanoma cells were co-injected with bone marrow MSCs derived from p53-deficient mice rather than MSCs from wild-type mice. Interestingly, this tumor-promoting effect by p53-deficient MSCs was not observed in non-obese diabetic/severe combined immunodeficiency mice, indicating the immune response has a critical role. Indeed, in the presence of inflammatory cytokines, p53-deficient MSCs expressed more inducible nitric oxide synthase (iNOS) and exhibited greater immunosuppressive capacity. Importantly, tumor promotion by p53-deficient MSCs was abolished by administration of S-methylisothiourea, an iNOS inhibitor. Therefore, our data demonstrate that p53 status in tumor stromal cells has a key role in tumor development by modulating immune responses.

Solid Pseudopapillary Neoplasms of the Pancreas: a 19-Year Multicenter Experience in China

AIM

The aim of this study was to determine the clinicopathological features, surgical management, and prognosis of solid pseudopapillary neoplasms (SPNs) of the pancreas.

METHODS

This study conducted a retrospective analysis of 97 patients who underwent surgery for a pathologically confirmed SPN in five hospitals between January 1996 and December 2014.

RESULTS

The 97 cases included 93 female and 4 male patients, and the average age was 31.2 years. The tumor was located in the body or tail (70.1%), the head (20.6%), and the neck (9.3%). All patients underwent surgical exploration, including distal pancreatectomy (63.9%), pancreaticoduodenectomy (20.6%) (partial portal vein or superior mesenteric vein resection and artificial vascular graft reconstruction performed in 4.1% of the patients), central pancreatectomy (10.3%), enucleation (5.2%), and liver resection (1.0%). 16.5% of the patients had malignant tumors. The positive rate of Ki-67 was 66.7% in patients diagnosed with a malignant neoplasm and was comparable to 8.4% of the patients diagnosed to have a benign neoplasm (p < 0.001). After a median follow-up of 70.1 months, three patients had recurrence and one patient died of liver metastasis.

CONCLUSIONS

SPN is a rare neoplasm with low malignant potential. Surgical resection is warranted even in the presence of local invasion or metastases as patients demonstrate excellent long-term survival. Positive immunoreactivity for Ki-67 may predict the malignant potential and poor outcome of SPNs.

Effect of Huaier on the proliferation and apoptosis of human gastric cancer cells through modulation of the PI3K/AKT signaling pathway

The aim of the present study was to investigate the effect of Huaier on the proliferation and apoptosis of the MKN45 and SGC7901 gastric cancer cell lines. The MTT assay was used to measure the effects of Huaier on the growth of the cells, while cell cycle distribution and apoptosis levels were analyzed using flow cytometry. Western blotting was used to assess the levels of proteins associated with the apoptotic pathway. It was found that cell survival decreased with the increase in the concentration of Huaier, and the apoptosis rates were increased in a dose-dependent manner both in MKN45 and SGC7901 cells. The number of cells in the G2/M phase in the Huaier-treated groups was increased in a dose-dependent manner compared with that in the control group. Huaier inhibited phosphorylated- (p-)AKT1, phosphatidylinositol 3-kinase (PI3K), pyruvate dehydrogenase kinase isoform 1, p-phosphatidylinositol 3,4,5-trisphosphate 3-phosphatase and dual-specificity protein phosphatase and B-cell lymphoma 2 expression and upregulated cleaved-caspase-9 expression in a dose-dependent manner. In conclusion, Huaier can strongly inhibit gastric cancer cell proliferation by inhibiting cyclin B1 expression, promoting G2/M-phase arrest and modulating the PI3K/AKT signaling pathway, and can induce gastric cancer cell apoptosis by modulating the PI3K/AKT signaling pathway in dose-dependent manner.

MIR210 as a potential molecular target to block invasion and metastasis of gastric cancer

The epithelial-mesenchymal transition (EMT) is a process driving invasion, recurrence, and metastasis of gastric cancer, and EMT is triggered by specific physiological factors that arise during tumorigenesis, such as hypoxia. Identifying the molecular mechanisms underlying EMT will potentially yield insight into the pathways fueling cancer recurrence and metastasis and thus, lead to novel molecular targets that will improve treatment of the disease. The microRNA210 (MIR210) is such a candidate molecule mediating EMT in gastric cancer based on a number of observations. First, MIR210 is often highly overexpressed in gastric cancer. Second, MIR210 is a hypoxia-specific miRNA, and its expression is significantly increased in hypoxic environments where EMT develops. Third, MIR210 is regulated by hypoxia inducible factor 1α (HIF-1α), a key transcription factor mediating important tumor associated processes such as EMT and angiogenesis in response to hypoxia during tumorigenesis. Finally, MIR210 has been intriguingly associated with Helicobacterpylori infection, which typically develops in an anaerobic environment and is known to have a causal role in the development of gastric cancer. Although studies have shown that MIR210 is often highly expressed in gastric cancer and associated with specific pathological conditions, functional experiments have not yet been performed to determine the role of MIR210 and downstream mediators in the development and progression of gastric cancer. Here, MIR210 is proposed as a viable molecular target in the treatment of gastric cancer, specifically for the inhibition of invasion and metastasis.

Treatment strategy and prognostic factors for Krukenberg tumors of gastric origin: report of a 10-year single-center experience from China

BACKGROUND

Gastric cancer patient with ovarian metastasis is common in clinical practice, but it is still uncertain whether surgical resection of ovarian metastasis could improve the outcome. This study aimed to explore the survival benefit of metastasectomy plus chemotherapy over chemotherapy alone in the treatment of Krukenberg tumors arising from gastric cancer and to identify prognostic factors.

RESULTS

A total of 152 patients were identified, including 93 patients with synchronous ovarian metastasis and 59 patients with metachronous ovarian metastasis. Overall survival (OS) was significantly better in metastasectomy group relative to the non-metastasectomy group for patients with synchronous ovarian metastasis (19.0 months vs. 11.8 months; P < 0.001) and those with metachronous ovarian metastasis (24.6 months vs. 14.3 months; P = 0.02), respectively. Metastasectomy (hazard ration [HR] 0.486; 95% confidence interval [CI] 0.323-0.729; P < 0.001), peritoneal carcinomatosis (HR 1.934; 95% CI 1.230-3.049; P = 0.004), and expression status of ER-β (HR 0.404; 95% CI 0.251-0.648; P < 0.001) and PR (HR 0.496; 95% CI 0.301-0.817; P < 0.001) were independent predictors of OS.

METHODS

All patients who were diagnosed with gastric cancer and ovarian metastases between January 2005 and December 2014 were included in the current study. Patients were subdivided according to treatment modality: the metastasectomy group (metastasectomy plus chemotherapy) and the non-metastasectomy group (chemotherapy alone). The clinicopathological features and the treatment records were reviewed in detail and their association with survival were analyzed.

CONCLUSION

Metastasectomy plus chemotherapy was associated with survival benefits in patients with Krukenberg tumors from gastric cancer. Metastasectomy, peritoneal carcinomatosis, and expression status of ER-β and PR were independent prognostic factors for survival.

Prediction of Peritoneal Cancer Index and Prognosis in Peritoneal Metastasis of Gastric Cancer Using NLR-PLR-DDI Score: A Retrospective Study

OBJECTIVE

The peritoneal cancer index (PCI) is used to evaluate the peritoneal metastasis of gastric cancer. A higher value indicates more widespread and/or larger tumors in the peritoneal cavity. The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are representative blood markers of systemic inflammatory responses, and D-dimer (DDI) is the final stable product of fibrin. This study explores the association of NLR, PLR, and DDI with PCI and assesses the clinical utility of a new blood score combining the NLR, PLR, and DDI (NPD score) for PCI and the prognosis prediction of gastric cancer.

METHODS

This was a single-center, nonrandomized, retrospective, cohort study. We evaluated the risk factors for high PCI (≥15) using univariate and multivariate analyses. According to the findings of the ROC analysis, we determined the cut-off values of NLR, PLR and DDI and created the NPD score. The patients were grouped into high-risk and low-risk groups based on their NPD score (<2 and ≥2, respectively).

RESULTS

Univariate and multivariate analysis demonstrated that the NLR, PLR, and DDI were independent risk factors for high PCI (P < 0.05). The NPD score of the high-risk group was ≥2, and the NPD score of the low-risk group was <2. The median survival time was 14.2 in the high-risk group and 25.6 in the low-risk group. The NPD score was significantly higher in the high-PCI group than that in the low-PCI group. The survival of the high-risk group was significantly worse than that of the low-risk group (P = 0.003). NPD score decrease was an independent predictive factor for PCI decrease.

CONCLUSION

NLR, PLR, and DDI are potential independent risk factors for high PCI in patients with peritoneal metastasis of gastric cancer. The NPD scoring system can help in predicting PCI and the prognosis of patients with peritoneal metastasis of gastric cancer.

Clinicopathologic features and surgical outcome of solid pseudopapillary tumor of the pancreas: analysis of 17 cases

BACKGROUND

We summarize our experience of the diagnosis, surgical treatment, and prognosis of solid pseudopapillary tumors (SPTs).

METHODS

We carried out a retrospective study of clinical data from a series of 17 patients with SPT managed in two hospitals between October 2001 and November 2011.

RESULTS

All of the 17 patients were female and the average age at diagnosis was 26.6 years (range 11 years to 55 years). The tumor was located in the body or tail in ten patients, the head in five patients, and the neck in two patients. The median tumor size was 5.5 cm (range 2 cm to 10 cm). All 17 patients had curative resections, including seven distal pancreatectomies, five local resections, four pancreaticoduodenectomies, and one central pancreatectomy. Two patients required concomitant splenic vein resection due to local tumor invasion. All patients were alive and disease-free at a median follow-up of 48.2 months (range 2 to 90 months). There were no significant associations between clinicopathologic factors and malignant potential of SPT. Ki-67 was detected in three patients with pancreatic parenchyma invasion.

CONCLUSIONS

The SPT is an infrequent tumor, typically affecting young women without notable symptoms. Surgical resection is justified even in the presence of local invasion or metastases, as patients demonstrate excellent long-term survival. Positive immunoreactivity for Ki-67 may predict the malignant potential of SPTs.

Reconstruction of middle hepatic vein in living donor liver transplantation with modified right lobe graft: a single center experience

Although a right liver graft without the middle hepatic vein (MHV) can cause congestion in the anterior segment, the reconstruction of MHV tributaries and the complex procedure remain controversial. Between November 2006 and October 2007, right liver transplantation without the MHV was performed in 31 cases. A retrospective analysis was conducted on clinical data and two groups were formed: with MHV reconstruction (Group I, n=16) and without MHV reconstruction (Group II, n=15). We analyzed the serum liver function markers at 3 weeks postoperatively and evaluated vascular flow in the graft and interpositional vein daily by Doppler ultrasonography during the hospital stay and monthly follow-up after discharge. One patient (6.7%) died of liver congestion and acute hepatic rejection on the postoperative day 10 in Group II. Congestion was observed in another three cases (20%) of Group II and one case (6.25%) of Group I. The levels of alanine transferase and aspartate transferase in Group II was higher than those in Group I in the first week after transplantation, albeit not significantly. In Group I, most of the interpositional vein grafts were the recipient's portal veins. Venoplasty in the graft was performed in three cases. All the interpositional veins and tectonic outflow orifices were detected to be patent by ultrasonography within 14 days after transplantation. The reconstruction of the MHV tributaries is necessary in the right liver graft without MHV according to our policy and better criteria for MHV reconstruction should be established. The recipient's portal vein is an optimal choice for the interpositional vein and hepatic venoplasty in living donor liver transplantation can simplify the operation and ensure excellent venous drainage.

TAK-242 can be the potential agents for preventing invasion and metastasis of hepatocellular carcinoma

The long-term prognosis of hepatocellular carcinoma (HCC) remains unsatisfactory even after surgical resection and chemoembolization because of a high recurrence rate. However, fewer agents are currently available to block or postpone HCC progression. Recent studies show that the activation of toll-like receptor 4 (TLR4)-NF-kappaB(NF-κB) signaling pathway can lead to the expression of interleukin (IL)-1, IL-6, IL-10, nitric oxide (NO) and tumor necrosis factor (TNF)-α, and promote chronic liver inflammation and malignant tumor development. A new small molecule TAK-242 (Resatorevid) can selectively inhibit TLR4-mediated signaling pathway and suppress the expression of inflammatory mediators. But the researches have not been reported whether TAK-242 can inhibit liver tumor growth and invasion. So it suggested a new hypothesis that TAK-242 selectively blocks the TLR4-NF-κB pathway and is hoped to be a potential and creative drug for preventing invasion and metastasis of HCC.

Management Of Synchronous Krukenberg Tumors From Gastric Cancer: a Single-center Experience

Background: Whether metastasectomy improves prognosis of gastric cancer patients with ovarian metastases (Krukenberg tumors) is not clear. In this study, we examined the survival benefit of metastasectomy combined with chemotherapy for treatment of synchronous Krukenberg tumors from gastric cancer and identified the prognostic factors. Methods: The subjects of this study were patients diagnosed as synchronous Krukenberg tumors of gastric origin in the period between December 2004 and December 2015. Patients were classified in accordance with treatment modality: metastasectomy group (metastasectomy combined with chemotherapy) and non-metastasectomy group (chemotherapy alone). Clinicopathological characteristics together with treatment records were investigated in detail and their relationship with survival outcomes was examined. Results: Out of a total of 103 patients, 54 (52.4%) underwent metastasectomy of Krukenberg tumors while 49 (47.6%) patients had chemotherapy alone. Overall survival (OS) in the metastasectomy group was significantly longer than that in the non-metastasectomy group (18.9 months vs. 12.4 months, respectively; P<0.001). Metastasectomy (hazard ratio [HR] 0.486; 95% confidence interval [CI] 0.323-0.729; P<0.001), signet ring cells (HR 1.938; 95% CI 1.182-3.175; P=0.009), peritoneal carcinomatosis (HR 1.934; 95% CI 1.230-3.049; P=0.004), expression of estrogen receptor-β (ER-β) (HR 0.404; 95% CI 0.251-0.648; P<0.001), and progesterone receptor (PR) (HR 0.496; 95% CI 0.301-0.817; P<0.001) were independent predictors of OS. Conclusion: Metastasectomy combined with chemotherapy showed an association with survival benefit in patients with synchronous Krukenberg tumors from gastric cancer. Metastasectomy, expression of ER-β and PR, peritoneal carcinomatosis, and signet ring cells were independent predictors of survival. Further prospective studies are warranted.

Deep Targeted Sequencing and Its Potential Implication for Cancer Therapy in Chinese Patients with Gastric Adenocarcinoma

INTRODUCTION

Gastric cancer (GC) has a high incidence and mortality rate, especially in East Asians, and about 90% of GCs are adenocarcinomas. Histological and etiological heterogeneity and ethnic diversity make molecular subtyping of GC complicated, thus making it difficult to determine molecular division systems and standard treatment modalities. Limited cohorts from South Korea, Singapore, Australia, and Japan have been studied; however, the mutational landscape of gastric adenocarcinomas in Chinese patients is still unknown.

METHODS

We performed a targeted sequencing panel focusing on cancer-related genes and tumor-associated microorganisms of 529 gastric adenocarcinoma samples with matched blood controls. We identified 449 clinically relevant gene mutations.

RESULTS

Approximately 47.1% of Chinese patients with GC harbored at least one actionable mutation. The top somatic mutations were TP53, ARID1A, LRP1B, PIK3CA, ERBB2, CDH1, KRAS, FAT4, CCNE1, and KMT2D. Truncation mutations of ARID1A, KMT2D, RNF43, TGFBR2, and CIC occurred in patients with high tumor mutational burden. Gene amplifications of ERBB2, CCNE1, CDK12, and CCND1 were detected in patients with low tumor mutational burden. Pathway analysis revealed common gene alterations in the Wnt and PI3K/Akt signaling pathways. The ratio of patients with high microsatellite instability was significantly lower than other cohorts, and high microsatellite instability and Epstein-Barr virus (EBV)-positive features seemed mutually inclusive in Chinese patients with GC. In 44 (8.3%) patients, 45 germline mutations were identified, among which SPINK1 mutations, all SPINK1 c.194 + 2T > C, were present in 15.9% (7/44) of patients. Microorganisms found in Chinese patients with GC included Helicobacter pylori, EBV, hepatitis B virus, and human papillomavirus types 16 and 18.

CONCLUSION

Identification of varied molecular features by targeted next-generation sequencing provides more insight into patient stratification and offers more possibilities for both targeted therapies and immunotherapies of Chinese patients with GC.

IMPLICATIONS FOR PRACTICE

This study investigated the genomic alteration profile of 529 Chinese patients with gastric adenocarcinoma by deep targeting sequencing, which might be the largest Chinese cohort on the genomic research of gastric adenocarcinoma up to now.

Comparison of D2 and D2 plus radical surgery for advanced distal gastric cancer: a randomized controlled study

BACKGROUND

The optimal extent of lymph node (LN) dissection for advanced distal gastric cancer remains controversial. The present study compared the safety and efficacy of extended LN dissection (D2 plus) with standard D2 radical surgery for advanced distal gastric cancer.

METHODS

Eligible patients were enrolled and randomly assigned into two groups: D2 group and D2 plus group. Patients in the D2 group received standard D2 LN dissection, while patients in the D2 plus group received an additional nos. 8p, 12b, 13, and 14v LNs dissection. The clinicopathological and surgical data of these two groups were compared, and the factors that may influence survival were analyzed.

RESULTS

Seventy patients were enrolled, out of which 64 patients were analyzed. There were no significant differences in the operative time, blood loss, and complications between the two groups. In the D2 plus group, the positive rate of the nos. 12b, 13, and 14v LN was 3.1%, 9.4%, and 12.5%, respectively. The positive rate of the no. 13 LN correlated with the duodenal involvement, while the positive rate of the no. 14v LN correlated with no. 6 LN metastasis. The survival analysis indicated that among patients with duodenum involvement, the 3-year disease-free survival rate of the D2 plus group was significantly better than that of the D2 group.

CONCLUSION

Duodenum involvement and positive no. 6 LN were high-risk factors of advanced distal gastric cancer. D2 plus radical surgery turned out to be safe and feasible, and may improve the prognosis of these patients. However, further clinical trials are still warranted.

TRIAL REGISTRATION

This study is registered with ClinicalTrials.gov as NCT01836991 , registered on 22 April 2013.

Deep learning radio-clinical signatures for predicting neoadjuvant chemotherapy response and prognosis from pretreatment CT images of locally advanced gastric cancer patients

BACKGROUND

Early noninvasive screening of patients who would benefit from neoadjuvant chemotherapy (NCT) is essential for personalized treatment of locally advanced gastric cancer (LAGC). The aim of this study was to identify radio-clinical signatures from pretreatment oversampled computed tomography (CT) images to predict the response to NCT and prognosis of LAGC patients.

METHODS

LAGC patients were retrospectively recruited from six hospitals from January 2008 to December 2021. An SE-ResNet50-based chemotherapy response prediction system was developed from pretreatment CT images preprocessed with an imaging oversampling method (i.e. DeepSMOTE). Then, the deep learning (DL) signature and clinic-based features were fed into the deep learning radio-clinical signature (DLCS). The predictive performance of the model was evaluated based on discrimination, calibration, and clinical usefulness. An additional model was built to predict overall survival (OS) and explore the survival benefit of the proposed DL signature and clinicopathological characteristics.

RESULTS

A total of 1060 LAGC patients were recruited from six hospitals; the training cohort (TC) and internal validation cohort (IVC) patients were randomly selected from center I. An external validation cohort (EVC) of 265 patients from five other centers was also included. The DLCS exhibited excellent performance in predicting the response to NCT in the IVC [area under the curve (AUC), 0.86] and EVC (AUC, 0.82), with good calibration in all cohorts ( P >0.05). Moreover, the DLCS model outperformed the clinical model ( P <0.05). Additionally, we found that the DL signature could serve as an independent factor for prognosis [hazard ratio (HR), 0.828, P =0.004]. The concordance index (C-index), integrated area under the time-dependent ROC curve (iAUC), and integrated Brier score (IBS) for the OS model were 0.64, 1.24, and 0.71 in the test set.

CONCLUSION

The authors proposed a DLCS model that combined imaging features with clinical risk factors to accurately predict tumor response and identify the risk of OS in LAGC patients prior to NCT, which can then be used to guide personalized treatment plans with the help of computerized tumor-level characterization.

Lentivirus-mediated inhibition of USP39 suppresses the growth of gastric cancer cells via PARP activation

Gastric cancer (GC) is the second most common cause of cancer-associated mortality worldwide. Ubiquitin-specific peptidase 39 (USP39) has important roles in mRNA processing and has been reported to be involved in the growth of breast cancer cells. However, the roles of USP39 in GC have remained to be investigated, which was the aim of the present study. A lentivirus expressing short hairpin RNA targeting USP39 was constructed and transfected into MGC80‑3 cells. Suppression of USP39 expression significantly decreased the proliferation and colony forming ability of MGC80‑3 cells as indicated by an MTT and a clonogenic assay, respectively. In addition, flow cytometric cell cycle analysis revealed that depression of USP39 induced G2/M‑phase arrest, while an intracellular signaling array showed that the cleavage of PARP at Asp214 was increased following USP39 knockdown. These results suggested that USP39 is involved in the proliferation of GCs and may be utilized as a molecular target for GC therapy.

Significance of MDR-related proteins in the postoperative individualized chemotherapy of gastric cancer

OBJECTIVES

Post-operative adjuvant chemotherapy was beneficial for some patients; however, it may increase the treatment burden and reduce the immunity of other patients. Screening appropriate patients based on molecular markers for individualized adjuvant chemotherapy was necessary.

MATERIALS AND METHODS

Between June 2002 and June 2004, 119 patients who underwent radical gastrectomy were retrospectively analyzed. Some patients had adjuvant chemotherapy based on platinum and 5-FU for four to six cycles. Topoisomerase II (ToPo II) negative, multidrug resistance protein (MRP) positive, and glutathione S-transferase π (GST-π) positive were regarded as three risk factors that may be associated with chemotherapy resistance and poor prognosis. Patients were divided into two groups: high-risk group (≥ 2 risk factors) and the low-risk group (<2 risk factors), and the tumor recurrence and patient survival time of the two groups were analyzed.

RESULTS

The average recurrence time of the low-risk group was significantly longer than that of the high-risk group (21.29 ± 11.10 versus 15.16 ± 8.05 months, P < 0.01).The 3-year and 5-year survival rate of the high-risk group was 57.4% and 42.6%; however, it had no significant difference compared to 66.2% and 58.5% of the low-risk group (P > 0.05). In the high-risk group, the 3-year survival rate of patients with/without chemotherapy were 62.1% and 52.0%, 5-year survival rates were 44.8% and 40.0%, respectively, but the difference was not statistically significant (P > 0.05). In the low-risk group, the 3-year survival rate of patients with/without chemotherapy were 81.2% and 51.5%, and the 5-year survival rates were 71.9% and 45.5%, respectively, and the differences were statistically significant (P < 0.05).

CONCLUSIONS

Multidrug resistance (MDR)-related proteins ToPo II, MRP, and GST-ð had great significance for the individualized post-operative chemotherapy and prognosis of gastric cancer.