Tumor reduction after SARS‑CoV‑2 infection in a patient with lung cancer: A case report

Lung cancer is one of the most common malignancies worldwide. Since the global outbreak of the coronavirus disease 2019 (COVID-19) pandemic in 2020, the impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on lung cancer has been extensively studied. Despite reports about SARS-CoV-2 infection inducing a significant increase in the number of medical visits for patients with cancer, the virus has also been reported to produce some unknown benefits. The present study reports the case of a patient with lung cancer whose tumor lesion was reduced in size after SARS-CoV-2 infection even though the therapeutic regimen remained unchanged. Although the mechanism involved is not yet understood, this case supports the novel idea of applying SARS-CoV-2 in oncolytic virotherapy.

PD-1 inhibitor combined with albumin paclitaxel and apatinib as second-line treatment for patients with metastatic gastric cancer: a single-center, single-arm, phase II study

BACKGROUND

Immune checkpoint inhibitors have been approved for first- and third-line treatment of advanced gastric cancer. However, pembrolizumab alone in the second line did not improve overall survival compared to chemotherapy in the KEYNOTE-061 study. In this study, we aimed to explore the efficacy and safety of a three-drug regimen of PD-1 inhibitor combined with albumin paclitaxel and apatinib (a VEGFR inhibitor) for the second-line treatment of patients with metastatic gastric cancer (mGC).

METHODS

This was a single-center, single-arm, phase II clinical study. Patients with mGC with stable microsatellite and negative HER-2 expression who failed first-line chemotherapy were enrolled. The enrolled patients were treated with PD-1 inhibitor (selected according to patients' requirements) in combination with albumin paclitaxel (125 mg/m2, intravenously, days 1 and 8, or 250 mg/m2, intravenously, day 1) and apatinib (250 or 500 mg, orally, days 1-21) every 3 weeks. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were overall survival (OS), objective response rate (ORR), disease control rate (DCR), duration of response, and adverse events (AEs).

RESULTS

From July 11, 2019, to October 13, 2022, a total of 43 patients were enrolled, of whom 10 were PD-L1 negative, 11 were PD-L1 positive, and 22 had unknown PD-L1 expression. As of the data cutoff on April 1st, 2023, nine patients had partial response, 29 had stable disease, and five experienced progressive disease, with the ORR of 20.9% and DCR of 88.3%. The median PFS was 6.2 months (95% CI, 3.9-9.3), and the median OS was 10.1 months (95% CI, 7.5-14.1). All patients suffered from alopecia and neurotoxicity. The other main AEs of grade 1 or 2 were bone marrow suppression (N = 21, 48.8%), hand-foot reaction (N = 19, 44.2%), hypertension (N = 18, 41.9%), hypothyroidism (N = 11, 25.6%), gastrointestinal bleeding (N = 3, 7.0%), and liver function damage (N = 5, 11.6%). Two patients reported grade 3-4 immune-related liver damage.

CONCLUSION

Second-line PD-1 inhibitor combined with albumin paclitaxel and apatinib showed certain efficacy and safety in patients with mGC.

TRIAL REGISTRATION

Clinical trials, NCT04182724. Registered 27 November 2019; retrospectively registered, https://clinicaltrials.gov/study/NCT04182724.

OncoCTMiner: streamlining precision oncology trial matching via molecular profile analysis

By establishing omics sequencing of patient tumors as a crucial element in cancer treatment, the extensive implementation of precision oncology necessitates effective and prompt execution of clinical studies for approving molecular-targeted therapies. However, the substantial volume of patient sequencing data, combined with strict clinical trial criteria, increasingly complicates the process of matching patients to precision oncology studies. To streamline enrollment in these studies, we developed OncoCTMiner, an automated pre-screening platform for molecular cancer clinical trials. Through manual tagging of eligibility criteria for 2227 oncology trials, we identified key bio-concepts such as cancer types, genes, alterations, drugs, biomarkers and therapies. Utilizing this manually annotated corpus along with open-source biomedical natural language processing tools, we trained multiple named entity recognition models specifically designed for precision oncology trials. These models analyzed 460 952 clinical trials, revealing 8.15 million precision medicine concepts, 9.32 million entity-criteria-trial triplets and a comprehensive precision oncology eligibility criteria database. Most significantly, we developed a patient-trial matching system based on cancer patients' clinical and genetic profiles, which can seamlessly integrate with the omics data analysis platform. This system expedites the pre-screening process for potentially suitable precision oncology trials, offering patients swifter access to promising treatment options. Database URL  https://oncoctminer.chosenmedinfo.com.

Construction of a nomogram to predict the survival of metastatic gastric cancer patients that received immunotherapy

Background

Immunotherapy has shown promising results for metastatic gastric cancer (MGC) patients. Nevertheless, not all patients can benefit from anti-PD-1 treatment. Thus, this study aimed to develop and validate a prognostic nomogram for MGC patients that received immunotherapy.

Methods

Herein, MGC patients treated with anti-PD-1 between 1 October 2016 and 1 June 2022 at two separate Chinese PLA General Hospital centers were enrolled and randomly divided into training and validation sets (186 and 80 patients, respectively). The nomogram was constructed based on a multivariable Cox model using baseline variables from the training cohort. Its predictive accuracy was validated by the validation set. The consistency index (C-index) and calibration plots were used to evaluate the discriminative ability and accuracy of the nomogram. The net benefit of the nomogram was evaluated using decision curve analysis (DCA). Finally, we stratified patients by median total nomogram scores and performed Kaplan–Meier survival analyses.

Results

We developed the nomogram based on the multivariate analysis of the training cohort, including four parameters: surgery history, treatment line, lung immune prognostic index (LIPI), and platelet-to-lymphocyte ratio (PLR). The C-index of the nomogram was 0.745 in the training set. The calibration curve for 1- and 2-year survival showed good agreement between nomogram predictions and actual observations. In the validation group, the calibration curves demonstrated good performance of the nomogram, with a C-index for overall survival (OS) prediction of 0.713. The OS of patients with a score greater than the median nomogram score was significantly longer than patients with a score lower or equal to the median (p < 0.001).

Conclusion

We constructed a nomogram to predict the outcomes of MGC patients that received immunotherapy. This nomogram might facilitate individualized survival predictions and be helpful during clinical decision-making for MGC patients under anti-PD-1 therapy.

Evaluation of circulating tumor DNA as a prognostic biomarker for metastatic pancreatic adenocarcinoma

Purpose

Pancreatic cancer is an aggressive solid tumor with a severe prognosis. Although tumor biomarkers are often used to identify advanced pancreatic cancer, this is not accurate, and the currently used biomarkers are not indicative of prognosis. The present study evaluated circulating tumor DNA (ctDNA) as a biomarker for prognosis prediction and disease monitoring in metastatic pancreatic adenocarcinoma (PAC).

Methods

From 2017 to 2018, 40 patients with metastatic PAC were enrolled, and tumor tissue and blood samples were collected from 40 and 35 patients, respectively. CtDNA was sequenced by next-generation sequencing (NGS) with a 425-gene capture panel. The association of clinical characteristics, laboratory indicators, and dynamic ctDNA with patient outcomes was analyzed.

Results

Mutations in KRAS (87.5%, N = 35) and TP53 (77.5%, N = 31) were most common in 40 tumor tissue. Patients’ ECOG score, CA19-9, CEA, neutrophil-lymphocyte ratio (NLR), platelet- lymphocyte ratio (PLR) levels and mutations in ≥ 3 driver genes were strongly correlated with patients’ overall survival (OS). Patients’ gender, ECOG score, CA19-9, and CEA levels were associated with progression-free survival (PFS) (P&lt;0.05). In 35 blood samples, univariate analysis showed a significant association between ECOG score, CA19-9, KRAS or CDKN2A mutation in ctDNA and OS and between CA19-9, CDKN2A or SMAD4 mutation in ctDNA and PFS. Cox hazard proportion model showed that patients’ CDKN2A mutation in ctDNA (HR=16.1, 95% CI=4.4-59.1, P&lt;0.001), ECOG score (HR=6.2, 95% CI=2.4-15.7, P&lt;0.001) and tumor location (HR=0.4, 95% CI=0.1-0.9, P=0.027) were significantly associated with OS. Patients’ CDKN2A mutation in ctDNA (HR=6.8, 95% CI=2.3-19.9, P=0.001), SMAD4 mutation in ctDNA (HR=3.0, 95% CI=1.1-7.9, P=0.031) and metastatic organ (HR=0.4, 95% CI=0.2-1.0, P=0.046) were significantly associated with PFS. Longitudinal changes in gene mutation allelic frequency (MAF) value were evaluated in 24 patients. Detection of progression disease (PD) by ctDNA was 0.9 months earlier than by radiological imaging (mean PFS: 4.6m vs 5.5m, P=0.004, paired t-test).

Conclusions

The ctDNA has the potential as a specific survival predictive marker for metastatic PAC patients. Longitudinal ctDNA tracking could potentially help identify disease progression and be a valuable complement for routine clinical markers and imaging.

Fruquintinib in Combination With PD-1 Inhibitors in Patients With Refractory Non-MSI-H/pMMR Metastatic Colorectal Cancer: A Real-World Study in China

Background

Fruquintinib, a vascular endothelial growth factor receptor inhibitor, is a new anticancer drug independently developed in China to treat refractory metastatic colorectal cancer (mCRC). In Japan, regorafenib combined with nivolumab has been demonstrated to be promising in patients with refractory mCRC. Here, in a real-world study, we were aimed to evaluate the efficacy of fruquintinib with various programmed death-1 (PD-1) inhibitors after standard treatment in Chinese non-microsatellite instability-high (MSI-H)/mismatch repair proficient mCRC patients.

Methods

A total of 45 patients with refractory mCRC were involved in the study. They received fruquintinib (3 or 5 mg, orally administered once a day for 3 weeks followed by 1 week off in 4-week cycles) and a PD-1 inhibitor(200 mg pembrolizumab, 3 mg/kg nivolumab, 200 mg sintilimab or camrelizumab, intravenously administered on D1 once every 3 weeks). Progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and objective response rate (ORR) were reviewed and evaluated.

Results

Among the 45 patients, the median age was 54 years (29-85). The ORR was 11.1% (5/45), DCR 62.2% (28/45), median PFS equal 3.8 months, and median OS was 14.9 months. The response duration was 3.4 months. PFS between left and right primary tumors and PFS with or without lung metastases were both not significantly different (p &gt; 0.05), which was inconsistent with the result of REGONIVO study. The multivariate analysis indicated no association of OS benefit in the specified subgroups. No adverse-effect-related deaths were reported.

Conclusions

Fruquintinib, in combination with anti-PD-1, was observed to have clinical activity in a small population of patients with heavily pretreated mCRC in our center. Further studies are needed to verify this outcome in a large population.

A phase II single-center single-arm study of PD-1 inhibitor in combination with albumin paclitaxel and apatinib as second-line treatment of metastatic gastric cancer (mGC)

e16024

Background: Immune checkpoint inhibitors have been approved for first- or third-line treatment of metastatic gastric cancer. However, pembrolizumab alone did not improve overall survival compared to second-line chemotherapy in the KEYNOTE-061 study. We aimed to explore the safety and efficacy of a three-drug regimen by carrying out a clinical study of PD-1 inhibitor combined with albumin paclitaxel and apatinib (VEGFR inhibitor) in the second-line treatment for patients with metastatic gastric cancer(mGC). Methods: This study was a single-center, single-arm phase II clinical study. patients harboring microsatellite stable (MSS) who had previously failed in first-line treatment were enrolled. The enrolled patients were given PD-1 inhibitor (PD-1 inhibitor selected according to the patients’ requirements) in combination with albumin paclitaxel (125 mg/m2 IV, D1, 8 days or 250 mg/m2 IV, D1, 250 mg and apatinib 250 or 500 mg orally for D1-21 days, every 3 weeks as a cycle). The primary endpoints were progression-free survival (PFS) and objective response rate (ORR), while the secondary endpoints were overall survival (OS) and safety (AEs), disease control rate (DCR). Results: From July 11, 2019 to December 1, 2021, a total of 23 patients were enrolled, of whom 10 had negative PD-L1 expression, 1 had PD-L1 > 70% expression, and 4 had positive PD-L1 expression. Preliminary results showed 8 cases had partial response (PR), 10 cases had stable disease (SD), and 5 cases of progression disease (PD). ORR was 34.8% and DCR was 78.3%. The median PFS was 5.04 m, and the median OS was not reached. The main adverse reactions of grade 1 to 2 were bone marrow suppression (42.8%), hand-foot reaction (21.4%), hypertension (21.4%), gastrointestinal bleeding (13.0%), hypothyroidism (8.7%), and liver function damage (8.7%). No grade 3-4 adverse reactions were reported. Conclusions: PD-1 inhibitor combined with albumin paclitaxel and apatinib in the second-line treatment of metastatic gastric cancer showed certain efficacy and safety. At present, this study is ongoing to further confirm the anti-tumor effect and survival benefit of this regimen. Clinical trial information: NCT04182724.

Retinoic Acid-Induced 2 (RAI2) Is a Novel Antagonist of Wnt/β-Catenin Signaling Pathway and Potential Biomarker of Chemosensitivity in Colorectal Cancer

Objective

Aberrant activation of Wnt/β-catenin signaling contributes to the maintenance of cancer stem cells and chemoresistance in colorectal cancer (CRC). Retinoic acid-induced 2 (RAI2) was proved to be a tumor suppressor in CRC in our previous report. In this study, the role of RAI2 in Wnt/β-catenin signaling was further investigated.

Methods

As a transcriptional co-regulator, C-terminal Binding Protein 2 (CtBP2) was reported to be involved in Wnt signaling in multiple and complex ways. The correlation of RAI2 and CtBP2 in CRC was analyzed by TCGA dataset, and the interaction between RAI2 and CtBP2 was explored by co-immunoprecipitation (Co-IP) in CRC cells. The effect of RAI2 on the activity of Wnt signaling and the location of β-catenin was detected by Dual-Luciferase reporter assay and Immunofluorescence respectively. Western blotting analysis was performed to detect the expression of target genes involved in Wnt signaling. Sphere formation assay was employed to detect the effect of RAI2 on stem cell like properties. Cell viability assay was used to detect the chemosensitivity of cells before and after transfection of RAI2.

Results

The interaction between RAI2 and CtBP2 was confirmed by Co-IP in CRC cells. Besides, the negative correlation of RAI2 and CtBP2 in CRC was found by analyzing the TCGA dataset. Re-expression of RAI2 in human colon cancer cells (HCT116 and LoVo) suppressed the fluorescent activity of Wnt signaling, increased the phosphorylation and inhibited nuclear translocation of β-catenin, with down-regulation of target genes like c-Myc, CyclinD1, ASCL2, and LGR5. In contrast, the mutated RAI2, which can’t interact with CtBP2, has no above effects. We observed low expression of RAI2 in 33.89% (101/298) of CRC patients, which was significantly associated with reduced phosphorylation of β-catenin (r=0.8866, P<0.0001), poor 5-year relapse-free survival (RFS) (P = 0.0029) and overall survival (OS) (P = 0.0102). Restoration of RAI2 in HCT116 and LoVo cells inhibited stem cell-like properties of CRC cells and increased chemosensitivity of these cells to oxaliplatin and fluorouracil.

Conclusion

Low expression of RAI2 can serve as an independent poor prognostic marker. RAI2 inhibits Wnt signaling by interacting with or down-regulating CtBP2, resulting in repression of stem cell-like properties and increased chemosensitivity of CRC cells.

Research on Mechanism of miR-214 Packaged with Lipidosome Nanoparticles on Prompting the Apoptosis of Intestinal Cancer Through Regulating p53 Pathway

Our study aimed at studying mechanism of miR-214 packaged with lipidosome nanoparticles on prompting apoptosis of intestinal cancer through regulating p53 pathway. SW480 cells were divided into blank group, empty carrier group, agonist group and group with carrier and antagonist. The negative control group was set, and groups related to p53 pathway were set as agonist group, inhibitor group and group with antagonist and inhibitor. The effect of miR-214 packaged with lipidosome nanoparticles on proliferation and apoptosis of intestinal cancer cells and p53 pathway in intestinal cancer cells was observed. Expression level of miR-214 in group with carrier and antagonist was lower than in other groups. The proportion of active cells in the group with carrier and antagonist started to be reduced notably from the second day. There was no notable declining tendency active cells' proportion from other groups. The quantity of cell apoptosis in group with carrier and antagonist was higher than in the other groups. The expression level of cleaved Caspase-3 in the group with carrier and antagonist was notably higher than in the other groups. Moreover, expression of Bcl-2/Bax protein was reversed, while expression of p53 protein in the carrier and antagonist groups was notably higher than in the other groups. The antagonist of miR-214 packaged with lipidosome nanoparticles could target on p53 pathway. The activity of p53 pathway was reduced by miR-214, and expression of Bcl-2 was increased. The expressions levels of Bax and cleaved Caspase-3 were also reversed, and molecular mechanism was mainly related with restraining of p53 signal pathway.

PD-1 Inhibitors Could Improve the Efficacy of Chemotherapy as First-Line Treatment in Biliary Tract Cancers: A Propensity Score Matching Based Analysis

Background

There are limited treatment options for advanced biliary tract cancers (BTCs), including intrahepatic cholangiocarcinoma, extrahepatic bile duct cancer, gallbladder cancer. We compared the efficacy and safety of PD-1 inhibitors plus chemotherapy and chemotherapy alone as first-line treatment in patients with advanced BTC.

Methods

We retrospectively reviewed patients with BTC treated at the oncology department of the Chinese PLA general hospital receiving PD-1 inhibitor with chemotherapy (anti-PD-1+C group) or chemotherapy alone (C group). Propensity Score Matching (PSM) (1:1) was performed to balance potential baseline confounding factors. Progression-free survival (PFS) was analyzed using Kaplan–Meier survival curves with log-rank tests. Objective response rate (ORR), disease control rate (DCR), and safety were also analyzed.

Results

This study included 75 patients who received PD-1 inhibitors (including Pembrolizumab, Nivolumab, Sintilimab, Toripalimab) plus chemotherapy and 59 patients who received chemotherapy alone. After matching, there were no significant differences between the two groups for baseline characteristics. Within the matched cohort, the median PFS was 5.8m in the anti-PD-1+C group, which was significantly longer than the C group, at 3.2m (HR: 0.47, 95% CI 0.29 to 0.76, P = 0.004). The ORR was 21.7% and DCR was 80.4% in the anti-PD-1+C group, while the ORR was 15.2% and DCR was 69.6% in the C group. No significant differences were found in the ORR and DCR between the two groups (P=0.423, P=0.231). Grade 3 or 4 treatment was related to adverse events (AEs) that occurred in the anti-PD-1+C group, namely hypothyroidism (n=3, 6.5%), rash (n=2, 4.2%), and hepatitis (n=1, 2.2%). There was no AE-related death. The grade 3-4 leukopenia rate was similar in the two groups (4.3% vs. 6.5%).

Conclusions

Anti-PD-1 therapy plus chemotherapy prolonged the PFS compared with chemotherapy alone in advanced BTC with controllable AEs. Further clinical trials are needed to confirm this result.

The Prognostic Value of Pre-treatment Hemoglobin (Hb) in Patients With Advanced or Metastatic Gastric Cancer Treated With Immunotherapy

Background

Biomarkers such as prevailing PD-L1 expression and TMB have been proposed as a way of predicting the outcome of immunotherapy in patients with advanced gastric cancer (AGC) and metastatic gastric cancer (MGC). Our study aims to investigate whether there is a link between pretreatment hemoglobin (Hb) levels and survival to immunotherapy in patients with AGC and MGC.

Methods

We retrospectively reviewed patients with AGC or MGC treated at the oncology department of the Chinese PLA general hospital receiving PD-1 inhibitor. The Propensity Score Matching (PSM) (1:1) was performed to balance potential baseline confounding factors. Progression-free survival (PFS) and overall survival (OS) was analyzed among different Hb level (normal Hb group and decreased Hb group). Objective response rate (ORR), disease control rate (DCR) were also analyzed. Univariate analysis and multivariate analysis were performed further to validate the prognostic value of Hb level.

Results

We included 137 patients with AGC and MGC who received PD-1 inhibitors (including Pembrolizumab, Nivolumab, Sintilimab, Toripalimab) in this study. After PSM matching, there were no significant differences between the two groups for baseline characteristics. Within the matched cohort, the median PFS was 7.8 months in the normal Hb level group and 4.3 months in the decreased Hb group (HR 95% CI 0.5(0.31, 0.81), P=0.004). The OS was 14.4 months with normal Hb level as compared with 8.2 months with decreased Hb level(HR 95% CI 0.59(0.37, 0.94), P=0.024). The ORR was 40.7% and DCR was 83.0% in the normal Hb group, while the ORR was 25.5% and DCR was 85.1% in the decreased Hb group. No significant differences were found in the ORR and DCR between the two groups (P=0.127, P=0.779). Univariate analysis and multivariate analysis showed that Hb level was only independent predictor for PFS and baseline Hb level was significant prognostic factor influencing the OS. Only when patients had normal Hb level, anti-pd-1 monotherapy or combined with chemotherapy was superior to anti-pd-1 plus anti-angiogenic therapy with respect to PFS (10.3 m vs 2.8 m, HR 95% CI 0.37(0.15, 0.95), P=0.031) and OS(15 m vs 5.7 m, HR 95% CI 0.21 (0.08, 0.58), P=0.001).

Conclusions

Our study have demonstrated that pretreatment Hb level was an independent prognostic biomarker in term of PFS and OS with immunotherapy for AGC and MGC patients. Correction of anemia for GC patients as immunotherapy would be a strategy to improve the survival. More data was warranted to further influence this finding.

Breast cancer exosomes contribute to pre-metastatic niche formation and promote bone metastasis of tumor cells

Rationale: Breast cancer preferentially develops osteolytic bone metastasis, which makes patients suffer from pain, fractures and spinal cord compression. Accumulating evidences have shown that exosomes play an irreplaceable role in pre-metastatic niche formation as a communication messenger. However, the function of exosomes secreted by breast cancer cells remains incompletely understood in bone metastasis of breast cancer. Methods: Mouse xenograft models and intravenous injection of exosomes were applied for analyzing the role of breast cancer cell-derived exosomes in vivo. Effects of exosomes secreted by the mildly metastatic MDA231 and its subline SCP28 with highly metastatic ability on osteoclasts formation were confirmed by TRAP staining, ELISA, microcomputed tomography, histomorphometric analyses, and pit formation assay. The candidate exosomal miRNAs for promoting osteoclastogenesis were globally screened by RNA-seq. qRT-PCR, western blot, confocal microscopy, and RNA interfering were performed to validate the function of exosomal miRNA. Results: Implantation of SCP28 tumor cells in situ leads to increased osteoclast activity and reduced bone density, which contributes to the formation of pre-metastatic niche for tumor cells. We found SCP28 cells-secreted exosomes are critical factors in promoting osteoclast differentiation and activation, which consequently accelerates bone lesion to reconstruct microenvironment for bone metastasis. Mechanistically, exosomal miR-21 derived from SCP28 cells facilitates osteoclastogenesis through regulating PDCD4 protein levels. Moreover, miR-21 level in serum exosomes of breast cancer patients with bone metastasis is significantly higher than that in other subpopulations. Conclusion: Our results indicate that breast cancer cell-derived exosomes play an important role in promoting breast cancer bone metastasis, which is associated with the formation of pre-metastatic niche via transferring miR-21 to osteoclasts. The data from patient samples further reflect the significance of miR-21 as a potential target for clinical diagnosis and treatment of breast cancer bone metastasis.

Divergent expression of DCLK1 in gastrointestinal neuroendocrine tumors and primary hepatic, gallbladder, and pancreatic neuroendocrine tumors

Doublecortin-like kinase 1 (DCLK1) is reported to be a negative prognostic marker in colorectal cancer and is involved in tumorigenesis and progression through several miRNA pathways. In this study, We analyzed its expression in neuroendocrine tumor (NET) and explored its relation with survival outcome. 122 patients were enrolled in the study, including 60 cases of GI-NETs, 24 cases of primary hepatic NETs (PHNETs), 16 cases of gallbladder NETs (GBNETs) and 22 cases of pancreatic NETs (pNETs). IHC was performed for DCLK1 on tumor tissue. All patients underwent a baseline visit, histologic determination, and a follow-up for survival. In the 60 cases of GI-NETs, DCLK1 showed diffuse cytoplasmic expression. The positive rates of DCLK1, Syn and CgA were 100% (60/60), 100% (60/60) and 36.7% (22/60), respectively. However, DCLK1 showed negative staining in all of the 62 cases of PHNETs, GBNETs, and pNETs. The mean score of DCLK1, Syn, and CgA were (5.77±2.012), (5.13±2.078) and (2.68±2.797), respectively. DCLK1 was correlated with primary site (P<0.001) and Syn expression (P = 0.045). Additionally, in GI-NETs, we found that DCLK1 expression was associated with worse OS (log-rank = 5.212, P = 0.022). The divergent expression of DCLK1 in NETs suggests different functional roles of DCLK1 in different locations of NET within the digestive system. However, with the limited number of tumor samples, its outcome prediciton still needs further investigation. DCLK1 expression may aid in the diagnosis and prognosis of GI-NETs.

Pd-1 inhibitors plus nab-paclitaxel with S1 (AS) as first line in patients with advanced biliary tract cancer

e15195

Background: The way to treat advanced biliary tract cancers (BTCs) including Intrahepatic cholangiocarcinoma, extrahepatic bile duct cancer, gallbladder cancer was disappointing. Hence, we explore the efficacy and safety of pd-1 inhibitors plus chemotherapy (nab-paclitaxel with S1, AS) as first line in patients with BTC. Methods: BTC patients from oncology department of Chinese PLA general hospital receiving PD-1 inhibitors with AS or AS alone were retrospectively analyzed. The primary endpoint was progression-free survival (PFS). The second endpoint was objective response rate (ORR), disease control rate (DCR) and safety. Results: 32 patients given pd-1 inhibitors (Pembrolizumab, Nivolumab, Sintilimab, Toripalimab) plus AS and 26 patients used AS alone were included in the study. The median PFS was 5.43m in combined group, significantly longer than the 2.82m with monotherapy alone group (HR 0.46, 95% CI 0.25–0.84, P = 0.01). OS was not matured in the pd-1 inhibitors group. PFS of Intrahepatic cholangiocarcinoma subgroup seemed better than extrahepatic group in the AS group (5.54m VS 2.57m, P = 0.004).however, there was no evidence of difference in intrahepatic group compared the other group in the pd-1 inhibitor group (5.07m vs 5.43m, P = 0.453). liver metastatic was poor predictor of PFS in both Pd-1 combined or not group (2.43m vs 7.63m, P = 0.01; 2.14m vs 5.54m, P = 0.04 ).ORR was 25% and DCR were 84.3% in Pd-1 inhibitor group and ORR was 15.3% and DCR was 69.2% in chemotherapy alone group respectively. No significant difference was seen for ORR and DCR compared between two groups (P = 0.364, P = 0.169). Grade 3 or 4 treatment-related adverse events(AE) in pd-1 inhibitor group were hypothyroidism (n = 3), rash (n = 2), hepatitis (n = 1). No AE related death. Myelosuppression was similar between the anti-PD-1 combination group and the chemotherapy alone group (12.5% and15.3 %, respectively). Conclusions: Anti-PD-1 therapy plus nab-paclitaxel with S1 prolonged the PFS and improved the ORR, DCR compared the nab-paclitaxel with S1 alone in advanced BTC with controllable AE. Further clinical trials were needed and we conduct the phrase II clinic trail of Toripalimab with AS (TSA-01 study) is ongoing (clinical registration number: NCT04027764).

Fruquintinib combination with sintilimab in refractory metastatic colorectal cancer patients in China

4028

Background: Fruquintinib, a vascular endothelial growth factor receptor (VEGFR) inhibitor, is a new anti-cancer targeting drug independently developed in China for refractory metastatic colorectal cancer (mCRC). Because Regorafenib combined with nivolumab has a promising future in patients with refractory mCRC, we aim to evaluate the efficiency of combination of Fruquintinib with Sintilimab (a highly selective, fully human monoclonal antibody PD-1 mAb) in these patients. Methods: Fifty-two patients with refractory mCRC were given fruquintinib (3mg orally, once daily for 3 weeks, followed by 1 weeks off in 4 weeks cycles) and sintilimab (200mg intravenously, once every 3 weeks). Before treatment, peripheral blood samples were collected and next-generation sequencing was performed to detect the gene profile of patients. Results: The ORR was 15.38% (8/52), DCR was 57.6% (30/52), and mPFS was 108 days. The patients was divided into two groups according to their PFS: PFS ≥ 90 days and PFS <90 days. PFS was significantly worse in patients with the following mutations: AMER1 ( p=0.0073), DNMT3A ( p=0.0075), ETV5 ( p=0.012), EWSR1 ( p=0.016), FANCA ( p=0.019), IKBKE ( p=0.0073), NOTCH1 ( p=0.015), STAG2 ( p=0.012) and TCF7L2 ( p=0.0073). It was also significantly worse in the patients had the abnormalities of complexity and coagulation cascades ( p = 0.026) and pancreatic cancer pathway ( p = 0.0098). Conclusions: Fruquintinib combined with Sintilimab seemed not resulted in a significant increase in ORR, DCR and OS in refractory mCRC. Certain mutational genes and abnormal pathway caused by some frameshift mutations may affect the efficacy. It is suggested that targeting these mutational genes and signaling pathway may be helpful to improve the efficacy of Fruquintinib combination with Sintilimab.

LncRNA HEIH promotes cell proliferation, migration and invasion in cholangiocarcinoma by modulating miR-98-5p/HECTD4

To date, a large set of long non-coding RNAs (lncRNAs) have been identified in tumorigenesis and progression. The present study focused on functions and mechanisms of HEIH in cholangiocarcinoma (CHOL). We started this study by testing the expression of HEIH in CHOL tissues by qRT-PCR technology. Next, loss-of-function experiments demonstrated the oncogenic nature of HEIH in CHOL. We also used bioinformatics tools to select miRNAs and mRNAs for support of the ceRNA network. Mechanistic experiments including RIP assay, luciferase reporter assay were carried out for further confirmation of binding situation among ceRNA molecules. At last, rescue experiments proved the ceRNA axis in CHOL. According to the results, HEIH expression was up-regulated in CHOL tissues and cells. Functionally, knockdown of HEIH attenuated cell proliferation, migration and invasion. Mechanistically, bioinformatics analysis, RIP assay and luciferase assay verified the ceRNA network among HEIH, miR-98-5p and HECTD4. Rescue experiments further demonstrated the oncogenic role of HEIH and HECTD4. The final in vivo experiments suggested that knockdown of HEIH restrained tumor growth both in weight and volume. In conclusion, HEIH promoted CHOL tumorigenesis and progression by miR-98-5p/HECTD4 axis, which opens up a new insight for CHOL therapeutics.

Mutant KRAS and TP53 with high mutation allelic frequency in ctDNA as poor outcome predictors in metastatic pancreatic cancer

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Background: This study was to investigate the feasibility and the prognostic value of circulating tumor DNA (ctDNA) in metastatic pancreatic cancer (MPC). Methods: From 2015 to 2018 in our center, 40 MPC patients treated with nab-paclitaxel based first-line chemotherapy were prospectively collected both tumor tissue and blood samples, in which the genomic profiling of 425 genes was identified by next-generation sequencing. High mutation allelic frequency (MAF) was defined > 30% and > 5% in tumor tissue and blood, respectively. Kappa statistics were used to compare mutant (mt) genes in tissue and ctDNA. Progression-free and overall survival (PFS, OS) were assessed with Kaplan-Meier and Cox methods. Results: Among 40 MPC patients, tumor tissue and blood samples were available in 34 and 38 patients for somatic and germline alternation test, respectively. The most commonly mutant gene were KRAS (31/34 in tissue with a median MAF of 29.4%, 29/38 in ctDNA with a mMAF of 8.2%), and TP53 (28/34 in tissue with a mMAF of 31.1%, 25/38 in ctDNA with a mMAF of 7.4%). Moderate agreement was seen between ctDNA and tumor tissue (mt KRAS: κ = 0.54, P = 0.001; mt TP53: κ = 0.74, P < 0.001). Mutation in CDNK2A and SMAD4 genes were detected in 8 and 6 patients in tissue and ctDNA, respectively. Germline alternation was found in 7 genes in 9 patients (9/40). High MAF of mt KRAS (r = 0.51, P = 0.005) or mt TP53 (r = 0.50, P = 0.005) in ctDNA was correlated with high CA199 levels (> 5000 u/ml) at baseline. MT KRAS in tissue with high MAF was associated with poor OS (high 7.5m vs low 10.1m, P = 0.001) in univariate and multivariate analyses (HR 3.87, 95%CI 1.47 to 10.19). Univariate analyses showed mt KRAS and mt TP53 in ctDNA with high MAF were associated with poor PFS ( KRAS and TP53: high 3.4m and 3.0m vs low 6.1m and 5.7m, P = 0.001 and P = 0.004, respectively) and OS ( KRAS and TP53: high 5.3m and 5.3m vs low 12.6m and 10.1m, P < 0.001, respectively). The presence of ctDNA in any above four mt driver gene with high MAF was associated with poor PFS (HR 3.79, 95%CI 1.71 to 8.42) and OS (HR 7.21, 95%CI 2.69 to 19.34) in multivariate COX model, when adjusted by age, sex, tumor differentiation, and baseline CA199 level. Conclusions: The presence of mt KRAS and mt TP53 with high MAF in ctDNA was associated with worse PFS and OS in MPC patients. Peripheral ctDNA testing demonstrated an alternative promising prognostic biomarker for MPC patients before treatment.

Apatinib combined with Raltitrexed in patients with metastatic colorectal cancer after failure of standard therapy (AHEAD-311): A single-arm phrase II pilot trial

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Background: To assess the safety and efficacy of apatinib, an oral vascular endothelial growth factor receptor-2 inhibitor, combined with thymidylate synthase inhibitor raltitrexed in patients with metastatic colorectal cancer (mCRC) as a third- or later-line therapy. Methods: Patients with mCRC after at least 2 lines of chemotherapy were enrolled whenever they previously treated with bevacizumab or not. Apatinib was given orally at 250mg or 500mg daily. Raltitrexed was administered intravenously at 3 mg/m2 on day 1 every 3 weeks. The primary endpoints were progression-free survival (PFS). The second endpoints were objective response rate (ORR), overall survival (OS) and safety. Results: From August 2017 to November 2018, thirty-one patients were enrolled in Chinese PLA General Hospital. After a median follow-up of 6.4 months, the median treatment cycle was 4. four patient achieved partial response(PR), and 11 patients achieved stable disease (SD) and 16 achieved progression disease (PD) in accordance with RECIST version 1.0, illustrating a DCR of 48.4% and an ORR of 12.9% .The Median PFS was 2.4 months and the median OS was 6.4 months. The most common adverse events were hypertension (n=12, 38.7%), nausea and vomiting (n=11, 33.8%), myelosuppression (n=9, 29.0%). The most common grade 3 to 4 adverse events were hypertension (n=2, 6.4%) and hand-foot syndrome (n=2, 6.4%). Grade 3 to 4 hematologic toxicities were rare. One patient died from cardiac arrest after three days treatment. There was no significantly association between PFS or OS, and clinical features including tumor location, KRAS status, and prior surgery or not, and number of metastatic organs. There was no trend showing patients who experienced had hypertension or myelosuppression had longer PFS and OS. Compared to the patients never received bevacizumab, the patients who had previously bevacizumab had the similar PFS and OS (3.9 versus 2.3months, P=0.787; 6.1 versus 6.4months, P=0.287). Grade1-2 nausea and vomiting and age <57 were independent predictors for longer PFS and OS. Conclusions: Apatinib combined with raltitrexed had efficacy but had limited survival benefit in mCRC refractory to standard chemotherapy. This regime showed us a higher risk of adverse event incidence and warrant further exploring of benefit population. Clinical trial information: NCT03344614 .

Efficacy and safety of apatinib in patients with previously treated metastatic colorectal cancer: a real-world retrospective study

No definitive treatment strategy has been established for patients with metastatic colorectal cancer (mCRC) who experienced progression after three or more lines of chemotherapy. A total of 36 mCRC patients were enrolled in this retrospective study who received apatinib therapy under non-clinical trial setting after progression in People’s liberation army general Hospital from March 2015 and August 2017. Progression free survival (PFS), overall survival (OS), disease control rate (DCR), objective response rate (ORR) and treatment-related adverse events (AEs) were reviewed and evaluated. Five patients achieved partial response (PR), and 25 achieved stable disease (SD), and 6 achieved progression disease (PD), illustrating a DCR of 83.3% and an ORR of 13.9%. Median PFS was 3.82 m and median OS was not reached. The toxicities associated with apatinib were generally acceptable with a total grade 3/4 adverse event incidence of 27.8%. The most common grade 3/4 adverse events were hypertension (n = 4, 11.1%), liver function damage (n = 3, 8.3%) and hand–foot syndrome (n = 2, 5.6%). No drug-related death occurred. Apatinib therapy provides a reasonable option with an acceptable safety profile for Chinese mCRC patients failed to prior chemotherapy.

Expression and prognostic significance of doublecortin-like kinase 1 in patients with hepatocellular carcinoma

Doublecortin-like kinase 1 (DCLK1), a putative cancer stem cell marker in intestinal and pancreatic tumors, is associated with tumor pathogenesis and progression, and poor survival outcomes in numerous types of cancer. However, DCLK1 expression and its prognostic value remain unclear in hepatocellular carcinoma (HCC). In the present study, the expression of DCLK1 was assessed using immunohistochemistry in 96 resected HCC and 68 adjacent tissue specimens. The staining intensity and the percentage of stained cells were scored on a scale of 0-3 and 0-4, respectively. Tissue was defined as positive for DCLK1 if the composite multiple score was >3. Cytoplasmic expression of DCLK1 was observed in HCC and adjacent tissue specimens with an expression rate of 81% (78/96) and 74% (50/68), respectively; the median score was 4.6 and 3.9, respectively, and no statistically significant difference was observed between HCC and adjacent tissues (P=0.087). DCLK1 expression was positively associated with intrahepatic metastasis (P=0.035). Furthermore, univariate analysis revealed that DCLK1 expression was significantly associated with poor disease-free survival (DFS) and overall survival (P=0.024 and 0.034). Multivariate analysis also demonstrated that DCLK1 expression was an independent prognostic factor for DFS in HCC (P=0.019; hazard ratio, 1.546; 95% confidence interval, 1.330-1.725). Stratified Kaplan-Meier survival curves revealed that DCLK1 expression predicted poorer DFS with respect to positivity for three characteristics: Portal venous metastasis, intrahepatic metastasis, and cirrhosis (P=0.020, P=0.007 and P=0.017, respectively). Collectively, the results of the present study suggested that DCLK1, functioning as a tumor promoter, is frequently overexpressed in HCC, and that DCLK1 expression is associated with poor DFS in patients with HCC. DCLK1 may represent a promising therapeutic target in HCC and requires further study.

Glucocorticoids impair bone formation of bone marrow stromal stem cells by reciprocally regulating microRNA-34a-5p

The inhibitory effects of glucocorticoids (GCs) on bone marrow stromal stem cell (BMSC) proliferation and osteoblastic differentiation are an important pathway through which GCs decrease bone formation. We found that microRNA-34a-5p was a critical player in dexamethasone (Dex)-inhibited BMSC proliferation and osteogenic differentiation. MicroRNA-34a-5p might be used as a therapeutic target for GC-impaired bone formation.

INTRODUCTION

The inhibitory effects of glucocorticoids (GCs) on bone marrow stromal stem cell (BMSC) proliferation and osteoblastic differentiation are an important pathway through which GCs decrease bone formation. The mechanisms of this process are still not completely understood. Recent studies implicated an important role of microRNAs in GC-mediated responses in various cellular processes, including cell proliferation and differentiation. Therefore, we hypothesized that these regulatory molecules might be implicated in the process of GC-decreased BMSC proliferation and osteoblastic differentiation.

METHODS

Western blot, quantitative real-time PCR, and cell proliferation and osteoblastic differentiation assays were employed to investigate the role of microRNAs in GC-inhibited BMSC proliferation and osteoblastic differentiation.

RESULTS

We found that microRNA-34a-5p was reciprocally regulated by Dex during the process of BMSC proliferation and osteoblastic differentiation. Furthermore, we confirmed that microRNA-34a-5p was a critical player in Dex-inhibited BMSC proliferation and osteogenic differentiation. Mechanistic studies showed that Dex inhibited BMSC proliferation by microRNA-34a-5p targeting cell cycle factors, including CDK4, CDK6, and Cyclin D1. Furthermore, downregulation of microRNA-34a-5p by Dex leads to Notch signaling activation, resulting in inhibition of BMSC osteogenic differentiation.

CONCLUSIONS

These results showed that microRNA-34a-5p, a crucial regulator for BMSC proliferation and osteogenic differentiation, might be used as a therapeutic target for GC-impaired bone formation.

Postoperative transarterial chemoembolization benefits patients with high γ-glutamyl transferase levels after curative hepatectomy for hepatocellular carcinoma: a survival stratification analysis

Hepatocellular carcinoma (HCC) is the most common liver tumor in Asian countries, and hepatectomy is currently regarded as the optimal curative treatment for HCC; however, the postoperative outcome remains unsatisfactory. Aiming at further clarification of prognostic factors after hepatectomy, we adopted a detailed stratification on survival periods. A total of 428 HCC patients undergoing curative hepatectomy were firstly divided into two groups using 2-year survival as cutoff point. Multivariate analysis showed that tumor-related factors, including vascular invasion (P < 0.001), high Edmondson grade (P < 0.001), large tumor size (P < 0.001) and high serum alpha-fetoprotein level (P = 0.001), were significant determinants for early death within 2 years, while postoperative transarterial chemoembolization (TACE) was demonstrated a protective factor (P = 0.013). Then the 281 patients with survival > 2 years were divided into two subgroups according to survival or death during follow-up to examine the late death related factors. We found that high serum γ-glutamyl transpeptidase (GGT), indicating severity of underlying liver disease, was significantly linked to death in this stage (P = 0.006). In further comparison of survival rates between subgroups stratified by early- and late-death indictors, we found the long-term outcomes of patients with high serum GGT were poor, regardless of the factors related with primary tumor. Furthermore, postoperative TACE decreased late death rate of patients with high GGT levels. In conclusion, despite the overwhelmed effects of primary tumor in the early stage after hepatectomy, postoperative TACE is beneficial for HCC patients with poor liver status.

Detection and clinical significance of lymph node micrometastasis in gastric cardia adenocarcinoma

OBJECTIVES

Lymph node micro metastasis was investigated in gastric cardia adenocarcinoma (GCA) patients without lymph node metastasis on routine pathological examination. The relationship between micrometastasis and clinicopathological features was also evaluated.

METHODS

A total of 349 lymph nodes were obtained from 45 patients with GCA. Micrometastases were detected by immunohistochemical staining for the markers cytokeratin 19 (CK19) and CD44 variant 6 (CD44v6).

RESULTS

A total of 33 lymph nodes (9.5%) from 15 patients (33.3%) were positive for CK19. Of these, 27 lymph nodes (7.7%) from 12 patients (26.7%) were also positive for CD44v6. Micrometastasis was significantly related to depth of tumour invasion and Lauren classification (intestinal or diffuse). The recurrence rate was significantly higher and 2-year survival rate significantly lower in patients with than in those without lymph node micrometastasis, showing the necessity of detecting micrometastasis in GCA patients who test negative for lymph node metastasis on routine examination.

CONCLUSION

CK19 and CD44v6 were shown to be good markers for micrometastasis detection.

Sinisan, a traditional Chinese medicine, attenuates experimental chronic pancreatitis induced by trinitrobenzene sulfonic acid in rats

BACKGROUND/PURPOSE

Sinisan, a traditional Chinese medicine, is effective for the treatment of gastrointestinal disorders. In this study, we investigated the potential protective role of Sinisan against chronic pancreatitis (CP) in rats.

METHODS

CP was induced in rats by intrapancreatic injection of trinitrobenzene sulfonic acid (TNBS). Rats were randomly divided into a sham group, a TNBS-induced CP group and a Sinisan-treated group. Serum amylase and histological score were used to evaluate the severity of disease. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cyclooxygenase-2 (COX-2), interleukin-10 (IL-10) and α-smooth muscle actin (α-SMA) were also measured in the three groups. Mechanical allodynia was measured with von Frey filaments. In addition, the protein levels of nerve growth factor (NGF) were measured in pancreatic tissues.

RESULTS

Administration of Sinisan significantly decreased the severity of CP. In the Sinisan-treated group, serum amylase, TNF-α, IL-1β, COX-2 and α-SMA levels were lower and the level of IL-10 was upregulated compared with the TNBS-induced CP group. Furthermore, treatment with Sinisan significantly, though not completely, attenuated the allodynia. Simultaneously NGF expression was also significantly downregulated in the Sinisan-treated group compared with the TNBS-induced CP group.

CONCLUSIONS

Sinisan could be an effective treatment modality for CP via its anti-inflammatory, anti-fibrotic and analgesic properties. It may be a promising drug candidate for the treatment of patients with CP.

Clinical applications of sentinel lymph node biopsy in ductal carcinoma in situ of the breast: a dilemma

Breast cancer is the fifth most common cause of cancer deaths in the world, which often spreads first to the axillary lymph nodes (ALN) from the primary tumor. ALN helps clinician stage breast cancer. In addition, it is one of the key prognostic factors for patients with invasive breast cancer. The sentinel lymph node (SLN) is defined as the first regional lymph node to receive lymphatic fluid from a malignant tumor. As a result, it seems possible to assess the complete nodal status with sentinel lymph node biopsy (SLNB), which is attractive and reliable approach for identifying lymph node metastasis. Ductal carcinoma in situ (DCIS) is the most common type of non-invasive breast cancer. However, the role of SLNB in DCIS is controversial because DCIS does not cause invasion and metastasis theoretically. In this review, clinical applications of SLNB in DCIS will be discussed. The potential benefit of accurately upstaging patients with DCIS and the minimal invasiveness of SLNB justify use of SLNB in selected high-risk DCIS patients. At least DSIS with microinvasion, have DCIS of sufficient extent on mammography or MRI, or indicated invasive or microinvasive focus by final histological examination, are recommended for SLNB. Moreover, large randomized trials to evaluate the usefulness of SLNB in DCIS patients after long-term follow-up on local control and survival are required for further evaluation.

Prognostic significance of tumor/stromal caveolin-1 expression in breast cancer patients

Caveolin-1 (Cav-1) has been extensively characterized in cancer biological research. However, the role of Cav-1 in the interaction between tumor and stromal cells remains unclear. In the present study, we examined Cav-1 expression in tumor cells and stromal cells in breast cancer tissue by immunohistochemical analysis and evaluated its prognostic value in a training cohort. Immunohistochemical analysis of Cav-1 expression was scored as (++), (+) or (-) according to the proportion of positively stained tumor cells (T) and stromal cells (S). Correlation analysis between tumor/stromal Cav-1 expression and clinicopathological parameters revealed that only T(++) Cav-1 status was positively associated with tumor size and histological nodal status (P = 0.019 and 0.021, respectively). Univariate analysis revealed that combined T(++)/S(-) status was significantly correlated with unfavorable prognostic outcomes (P < 0.001). Multivariate analysis demonstrated that this combined status is an independent prognostic factor for primary breast cancer (P = 0.002). Clinical outcomes in different subgroups of breast cancer patients were also strictly dependent on this combined status (P < 0.05). The prognostic value of T(++)/S(-) Cav-1 status was also validated in the testing cohort. Collectively, our data indicate that high Cav-1 expression in tumor cells and lack of this expression in stromal cells could help identify a particular subgroup of breast cancer patients with potentially poor survival. Further studies are required to understand the regulatory mechanism of Cav-1 in the tumor microenvironment.

Caveolin-1 is related to invasion, survival, and poor prognosis in hepatocellular cancer

Caveolin-1 is the principal components of caveolae membranes, implicated in oncogenesis and angiogenesis. Until now, its expression and functional significance in hepatocellular carcinoma (HCC) are still unclear. In the present study, we demonstrated that expression of caveolin-1 was markedly upregulated in HCC patients. In addition, increased caveolin-1 expression correlated positively with the histological differentiation, portal venous invasion, hepatic venous invasion, intrahepatic metastases, and recurrence, suggesting a role for caveolin-1 in the progression of HCC. HepG2 cell line was transfected with pcDNA3.1/caveolin-1 to observe the significance of the change in caveolin-1 expression. We showed that caveolin-1 overexpression could not only protect HepG2 cells from apoptosis but also enhance its migration and invasion by upregulating MMP-2, MMP-9, and VEGF expressions. Collectively, our clinical and in vitro data indicate that the status of caveolin-1 expression may be one of causative factors for the invasion and poor prognosis in HCC.

MicroRNAs involved in neoplastic transformation of liver cancer stem cells

Background

The existence of cancer stem cells in hepatocellular carcinoma (HCC) has been verified by characterizing side population (SP) cells based on efflux of Hoechst 33342 dye from stem cells. Recent advances in microRNA (miRNA) biology have revealed that miRNAs play an important role in embryonic development and tumorigenesis. However, it is still unclear which miRNAs participate in the neoplastic transformation of liver cancer stem cells (LCSCs) during hepatocarcinogenesis.

Methods

To identify the unique set of miRNAs differentially regulated in LCSCs, we applied SP sorting to primary cultures of F344 rat HCC cancer cells treated with diethylnitrosamine (DEN) and normal syngenic fetal liver cells, and the stem-like characteristics of SP cells were verified through detecting expression of CD90.1, AFP and CK-7. Global miRNA expression profiles of two groups of SP cells were screened through microarray platform.

Results

A total of 68 miRNAs, including miR-10b, miR-21, miR-470*, miR-34c-3p, and let-7i*, were identified as overexpressed in SP of HCC cells compared to fetal liver cells. Ten miRNAs were underexpressed, including miR-200a* and miR-148b*. These miRNAs were validated using stem-loop real-time reverse transcriptase polymerase chain reaction (RT-PCR).

Conclusions

Our results suggest that LCSCs may have a distinct miRNA expression fingerprint during hepatocarcinogenesis. Dissecting these relationships will provide a new understanding of the function of miRNA in the process of neoplastic transformation of LCSCs.

Quantitative studies of the distribution pattern for Salmonella Enteritidis in the internal organs of chicken after oral challenge by a real-time PCR

This research was undertaken to identify and understand the regular distribution pattern for Salmonella Enteritidis (S. enteritidis) in the internal organs of chicken after oral challenge over a 3 wk period. We used a real-time, fluorescence-based quantitative polymerase chain reaction (FQ-PCR) to detect genomic DNA of S. enteritidis in the blood and the internal organs, including heart, liver, spleen, kidney, pancreas, and gallbladder, from chicken after oral challenge at different time points. The results showed that the spleen was positive at 12 h post inoculation (PI), and the blood was at 14 h PI. The organism was detected in the liver and heart at 16 h PI, pancrea was positive at 20 h PI, and the final organ to show a positive results were the kidney and gallbladder at 22 h PI. The copy number of S. enteritidis DNA in each tissue reached a peak at 24 h-36 h PI, with the liver and spleen containing high concentrations of S. enteritidis, whereas the blood, heart, kidney, pancreas, and gallbladder had low concentrations. S. enteritidis populations began to decrease and were not detectable at 3 d PI, but were still present up to 12 d PI in the gallbladder, 2 wk for the liver, and 3 wk for the spleen without causing apparent symptoms. The results showed that the liver and spleen may be the primary sites for S. enteritidis setting itself up as a commensa over a long time after oral challenge. Interestingly, it may be the first time reported that the gallbladder is a site of carriage for S. enteritidis over a 12 d period. This study will help to understand the mechanisms of action of S. enteritidis infection in vivo.

Clinical and molecular survey in 124 Chinese patients with Leigh or Leigh-like syndrome

Leigh syndrome is the most common mitochondrial disorder in children characterized by necrotic lesions in the central nervous system. Both mitochondrial DNA (mtDNA) and nuclear DNA defects in the mitochondrial respiratory chain can lead to this disease. To characterize the clinical and genetic traits of Leigh or Leigh-like syndrome patients in China, 124 unrelated cases were collected between 1992 and 2005. Seventy-seven cases (62.1%) met the typical criteria of Leigh syndrome, including symmetrical bilateral abnormal signals in the basal ganglia, thalamus and brain stem, etc. Other cases (37.9%) belonged to Leigh-like syndrome with atypical clinical or radiological manifestations. Late-onset patients accounted for 20.2%, which is more than previously reported. Movement disorder was the most common symptoms in our patients. Thirty-two patients (25.8%) were confirmed to carry mutant genes. Among them, six cases (4.8%) have been demonstrated to have point mutations in mitochondrial DNA. Two separate patients were detected to have mutations on A8344G and A3243G. The T8993G point mutation was identified in one patient and T8993C in one other patient. SURF1 mutations associated with cytochrome-c oxidase deficiency were identified in 25 patients (20.2%). Four unreported variations have been identified in SURF1 gene from three patients. G604C was found in 22 patients. Only one patient had C214T mutation in the pyruvate dehydrogenase E1alpha subunit gene. In the remaining 92 patients (74.2%), a specific molecular dysfunction or underlying metabolic abnormality could not be identified.

Relationship between LAPTM4B gene polymorphism and susceptibility of gastric cancer

BACKGROUND

A novel gene called LAPTM4B (lysosome-associated protein transmembrane 4beta) was mapped to 8q22, and contains seven exons. The 2.25-kb messenger RNA of the gene encodes a putative lysosome-associated protein with four transmembrane regions. There are two alleles of the gene, named as LAPTM4B*1 and LAPTM4B*2. Allele *1 differs from allele *2 in that it contains only one copy of a 19-bp sequence in the 5' untranslated region (UTR), whereas this sequence is duplicated and tandemly arranged in allele *2. Studies showed that the allelic variation of LAPTM4B was associated with the genetic susceptibility of hepatocellular carcinoma but not with that of esophageal squamous cell carcinoma. This study was designed to investigate the possible association between the allelic variation of LAPTM4B and the genetic susceptibility of gastric cancer.

MATERIALS AND METHODS

The genotype of LAPTM4B was analyzed in 350 unrelated healthy adult individuals and 214 patients with gastric cancer by utilizing polymerase chain reaction based on specific primers. The genotypic distribution of LAPTM4B was analyzed by chi(2) test.

RESULTS

The allelic frequencies of the *2 were 33.88% and 24.14% in the gastric cancer group and the healthy control group, respectively, which was significantly different between the two groups (P < 0.001). There was a significant difference in the overall genotypic distribution between the patients and the controls (P = 0.023). The risk of suffering from gastric cancer was increased 1.819 times in the individuals of the *1/2 genotype [95% confidence interval (CI) 1.273-2.601] and 2.387 times in the individuals of the *2/2 genotype of LAPTM4B (95% CI 1.195-4.767) compared with the *1/1 genotype. No association between the genotypic distribution of LAPTM4B and the clinical information on patients of gastric cancer such as age, pathological type, differentiation classification of TNM, and infection of hepatitis B virus was shown.

CONCLUSION

This study indicated that allele *2 of LAPTM4B might be the risk factor of gastric cancer, which could be associated with genetic susceptibility of gastric cancer.

Motion rivalry impairs motion repulsion

In their classic study on motion repulsion, Marshak and Sekuler (Science 205 (1979) 1399) reported a repulsion of up to 10 degrees when two different directions of motion were presented dichoptically. However, subjects in that study did not experience binocular rivalry, presumably because of the brief presentation time. In the present study, we measured repulsion during binocular rivalry by requiring subjects to dichoptically view the stimuli until one direction of motion appeared to exclusively dominate the other (Blake, Yu, Lokey, & Norman (1998). J. Cogn. Neurosci., 10, 46-60). We found that motion repulsion was significantly reduced during exclusive dominance. Indeed, after controlling for reference repulsion--the misjudgment of a single direction of motion (Rauber & Treue (1998). Perception, 27, 393-402)--we found no significant motion repulsion during exclusive dominance. These data suggest that motion repulsion may require the perception, rather than merely the physical presence, of multiple directions.

Transcranial magnetic stimulation differentially affects speed and direction judgments

This study was conducted to determine whether humans' judgments about the speed and direction of moving stimuli was differentially affected by transcranial magnetic stimulation (TMS). Subjects viewed two successively presented moving stimuli that differed from each other both in speed and direction of motion. Single-pulse TMS was applied either medially (approximately 2 cm above the inion) or laterally (approximately 5 cm lateral to and 4 cm above the inion), while subjects judged the speed and direction differences. The physical stimulation (visual and TMS) was identical on the two tasks, as was discriminability (d') when TMS was not applied. We found significant criterion (beta) shifts on the speed discrimination task at both stimulation sites. Specifically, on TMS trials the proportion of "slower" judgments increased significantly, consistent with subjective reports that stimuli often appeared to slow when TMS was applied. The subjective reports indicated no corresponding change in perceived direction. We also found that speed discriminability was impaired significantly more than direction discriminability, but only when TMS was applied medially. Indeed, after controlling for TMS-related changes in reaction time, speed discriminability was impaired significantly, while direction discriminability remained largely intact. This dissociation suggests that the sensory response constraining speed discrimination is at least partially independent from the sensory response constraining direction discrimination. Combined with previous psychophysical data, the present data suggest a double dissociation between speed and direction discrimination in humans.

Practising orientation identification improves orientation coding in V1 neurons

The adult brain shows remarkable plasticity, as demonstrated by the improvement in fine sensorial discriminations after intensive practice. The behavioural aspects of such perceptual learning are well documented, especially in the visual system. Specificity for stimulus attributes clearly implicates an early cortical site, where receptive fields retain fine selectivity for these attributes; however, the neuronal correlates of a simple visual discrimination task remained unidentified. Here we report electrophysiological correlates in the primary visual cortex (V1) of monkeys for learning orientation identification. We link the behavioural improvement in this type of learning to an improved neuronal performance of trained compared to naive neurons. Improved long-term neuronal performance resulted from changes in the characteristics of orientation tuning of individual neurons. More particularly, the slope of the orientation tuning curve that was measured at the trained orientation increased only for the subgroup of trained neurons most likely to code the orientation identified by the monkey. No modifications of the tuning curve were observed for orientations for which the monkey had not been trained. Thus training induces a specific and efficient increase in neuronal sensitivity in V1.

Modeling V1 disparity tuning to time-varying stimuli

Most models of disparity selectivity consider only the spatial properties of binocular cells. However, the temporal response is an integral component of real neurons' activities, and time-varying stimuli are often used in the experiments of disparity tuning. To understand the temporal dimension of V1 disparity representation, we incorporate a specific temporal response function into the disparity energy model and demonstrate that the binocular interaction of complex cells is separable into a Gabor disparity function and a positive time function. We then investigate how the model simple and complex cells respond to widely used time-varying stimuli, including motion-in-depth patterns, drifting gratings, moving bars, moving random-dot stereograms, and dynamic random-dot stereograms. It is found that both model simple and complex cells show more reliable disparity tuning to time-varying stimuli than to static stimuli, but similarities in the disparity tuning between simple and complex cells depend on the stimulus. Specifically, the disparity tuning curves of the two cell types are similar to each other for either drifting sinusoidal gratings or moving bars. In contrast, when the stimuli are dynamic random-dot stereograms, the disparity tuning of simple cells is highly variable, whereas the tuning of complex cells remains reliable. Moreover, cells with similar motion preferences in the two eyes cannot be truly tuned to motion in depth regardless of the stimulus types. These simulation results are consistent with a large body of extant physiological data, and provide some specific, testable predictions.

The effect of orientation learning on contrast sensitivity

Regan and Beverley [Regan, D., & Beverley, K. I. (1985). Postadaptation orientation discrimination. Journal of the Optical Society of America A, 2(2), 147-155] previously demonstrated that adapting to an oriented visual stimulus improves sensitivity to subtle orientation differences while impairing contrast sensitivity. Here, we investigated whether practice-based improvements in orientation sensitivity would, like adaptation, impair contrast sensitivity. To the contrary, we found that contrast sensitivity actually improved significantly after observers demonstrated practice-based increases in orientation sensitivity. Therefore, while orientation sensitivity can be enhanced either by orientation-discrimination training or by adapting to visual stimuli, these two procedures have opposite effects on contrast sensitivity. This difference suggests that adaptation and perceptual learning on orientation discrimination cannot be explained sufficiently by a shared underlying cause, such as a reduction in neural activity.

A physiologically-based explanation of disparity attraction and repulsion

Westheimer and Levi [(1987) Vision Research, 27, 1361-1368] found that when a few isolated features are viewed foveally, the perceived depth of a feature depends not only on its own disparity but also on those of its neighbors. The nature of this interaction is a function of the lateral separation between the features: When the distance is small the features appear to attract each other in depth but the interaction becomes repulsive at larger distances. Here we introduce a two-dimensional extension of our recent stereo model based on the physiological studies of Ohzawa, DeAngelis and Freeman [(1990) Science, 249, 1037-1041] and demonstrate through analyses and simulations that these observations can be naturally explained without introducing ad hoc assumptions about the connectivity between disparity-tuned units. In particular, our model can explain the distance-dependent attraction/repulsion phenomena in both the vertical-line configuration used by Westheimer [(1986) Journal for Neurophysiology, 370, 619-629], and the horizontal-line-and-point configuration used by Westheimer and Levi. Thus, the psychophysically observed disparity interaction may be viewed as a direct consequence of the known physiological organization of the binocular receptive fields. We also find that the transition distance at which the disparity interaction between features changes from attraction to repulsion is largely determined by the preferred spatial frequency and orientation distributions of the cells used in the disparity computation. This result may explain the observed variations of the transition distance among different subjects in the psychophysical experiments. Finally, our model can also reproduce the observed effect on the perceived disparity when the disparity magnitude of the neighboring features is changed.

The dependence of motion repulsion and rivalry on the distance between moving elements

We investigated the extent to which motion repulsion and binocular motion rivalry depend on the distance between moving elements. The stimuli consisted of two sets of spatially intermingled, finite-life random dots that moved across each other. The distance between the dots moving in different directions was manipulated by spatially pairing the dot trajectories with various precisions. Data from experiment 1 indicated that motion repulsion occurred reliably only when the average distance between orthogonally moving elements was at least 21.0 arc min. When the dots were precisely paired, a single global direction intermediate to the two actual directions was perceived. This result suggests that, at a relatively small spatial scale, interaction between different directions favors motion attraction or coherence, while interaction at a somewhat larger scale generates motion repulsion. Similarly, data from experiment 2 indicated that binocular motion rivalry was significantly diminished by spatially pairing the dots, which moved in opposite directions in the two eyes. This supports the recent proposal that rivalry occurs at or after the stage of binocular convergence, since monocular cells could not have directly responded to our interocular pairing manipulation. Together, these findings suggest that the neural mechanisms underlying motion perception are highly sensitive to the fine spatial relationship between moving elements.

Relationship between phase and energy methods for disparity computation

The phase and energy methods for computing binocular disparity maps from stereograms are motivated differently, have different physiological relevances, and involve different computational steps. Nevertheless, we demonstrate that at the final stages where disparity values are made explicit, the simplest versions of the two methods are exactly equivalent. The equivalence also holds when the quadrature-pair construction in the energy method is replaced with a more physiologically plausible phase-averaging step. The equivalence fails, however, when the phase-difference receptive field model is replaced by the position-shift model. Additionally, intermediate results from the two methods are always quite distinct. In particular, the energy method generates a distributed disparity representation similar to that found in the visual cortex, while the phase method does not. Finally, more elaborate versions of the two methods are in general not equivalent. We also briefly compare these two methods with some other stereo models in the literature.

Perceptual learning on orientation and direction discrimination

Two experiments were conducted to determine the extent to which perceptual learning transfers between orientation and direction discrimination. Naive observers were trained to discriminate orientation differences between two single-line stimuli, and direction differences between two single-moving-dot stimuli. In the first experiment, observers practiced the orientation and direction tasks along orthogonal axes in the fronto-parallel plane. In the second experiment, a different group of observers practiced both tasks along a single axis. Perceptual learning was observed on both tasks in both experiments. Under the same-axis condition, the observers' orientation sensitivity was found to be significantly elevated after the direction training, indicating a transfer of learning from direction to orientation. There was no evidence of transfer in any other cases tested. In addition, the rate of learning on the orientation task was much higher than the rate on the direction task. The implications of these findings on the neural mechanisms subserving orientation and direction discrimination are discussed.