P53 mutations in triple negative breast cancer upregulate endosomal recycling of epidermal growth factor receptor (EGFR) increasing its oncogenic potency

Immunoglobulin superfamily 9 (IGSF9) is trans-activated by p53, inhibits breast cancer metastasis via FAK

Metastasis of breast cancer represents the major reason for its poor prognosis, leading to high mortality. In breast cancer, a tumor suppressor gene TP53 is commonly mutated. TP53 mutation leads to an altered expression of various genes, an event that is associated with aggressive tumor and is a strong independent marker for survival. In this study, we identified a novel p53 target gene, immunoglobulin superfamily 9 (IGSF9). IGSF9 is generally down-regulated in breast cancer tissues. Loss of IGSF9 is associated with frequent metastasis and poor prognosis of breast cancer patients. Wild-type p53, but not R175H mutant, trans-activates the transcription of IGSF9 via binding to its promoter (−137 to −131 bp), inhibits epithelial-mesenchymal transition (EMT), consequently the inhibition of breast cancer cells migration and invasion. IGSF9 interacts with focal adhesion kinase (FAK) and inhibits FAK/AKT signaling activity. PND1186, FAK inhibitor, inhibits breast cancer metastasis induced by IGSF9 knockdown in vitro and in vivo. Taken together, IGSF9 is trans-activated by p53 and inhibits breast cancer metastasis by modulating FAK/AKT signaling pathway. IGSF9 could serve as a prognostic marker and potential therapeutic target for breast cancer.

Can EGFR be a therapeutic target in breast cancer?

Epidermal growth factor receptor (EGFR) is highly expressed in certain cancer types and is involved in regulating the biological characteristics of cancer progression, including proliferation, metastasis, and drug resistance. Various medicines targeting EGFR have been developed and approved for several cancer types, such as lung and colon cancer. To date, however, EGFR inhibitors have not achieved satisfactory clinical results in breast cancer, which continues to be the most serious malignant tumor type in females. Therefore, clarifying the underlying mechanisms related to the ineffectiveness of EGFR inhibitors in breast cancer and developing new EGFR-targeted strategies (e.g., combination therapy) remain critical challenges. Various studies have demonstrated aberrant expression and maintenance of EGFR levels in breast cancer. In this review, we summarize the regulatory mechanisms underlying EGFR protein expression in breast cancer cells, including EGFR mutations, amplification, endocytic dysfunction, recycling acceleration, and degradation disorders. We also discuss potential therapeutic strategies that act directly or indirectly on EGFR, including reducing EGFR protein expression, treating the target protein to mediate precise clearance, and inhibiting non-EGFR signaling pathways. This review should provide new therapeutic perspectives for breast cancer patients with high EGFR expression.

Prognostic analysis of cuproptosis-related gene in triple-negative breast cancer

Background

Cuproptosis is a copper-dependent cell death mechanism that is associated with tumor progression, prognosis, and immune response. However, the potential role of cuproptosis-related genes (CRGs) in the tumor microenvironment (TME) of triple-negative breast cancer (TNBC) remains unclear.

Patients and methods

In total, 346 TNBC samples were collected from The Cancer Genome Atlas database and three Gene Expression Omnibus datasets, and were classified using R software packages. The relationships between the different subgroups and clinical pathological characteristics, immune infiltration characteristics, and mutation status of the TME were examined. Finally, a nomogram and calibration curve were constructed to predict patient survival probability to improve the clinical applicability of the CRG_score.

Results

We identified two CRG clusters with immune cell infiltration characteristics highly consistent with those of the immune-inflamed and immune-desert clusters. Furthermore, we demonstrated that the gene signature can be used to evaluate tumor immune cell infiltration, clinical features, and prognostic status. Low CRG_scores were characterized by high tumor mutation burden and immune activation, good survival probability, and more immunoreactivity to CTLA4, while high CRG_scores were characterized by the activation of stromal pathways and immunosuppression.

Conclusion

This study revealed the potential effects of CRGs on the TME, clinicopathological features, and prognosis of TNBC. The CRGs were closely associated with the tumor immunity of TNBC and are a potential tool for predicting patient prognosis. Our data provide new directions for the development of novel drugs in the future.

Clustering subtypes of breast cancer by combining immunohistochemistry profiles and metabolism characteristics measured using FDG PET/CT

Background

The aim of this study was to investigate the effect of combining immunohistochemical profiles and metabolic information to characterize breast cancer subtypes.

Methods

This retrospective study included 289 breast tumors from 284 patients who underwent preoperative ¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography/ computed tomography (PET/CT). Molecular subtypes of breast cancer were classified as Hormonal, HER2, Dual (a combination of both Hormonal and HER2 features), and triple-negative (TN). Histopathologic findings and immunohistochemical results for Ki-67, EGFR, CK 5/6, and p53 were also analyzed. The maximum standardized uptake value (SUV) measured from FDG PET/CT was used to evaluate tumoral glucose metabolism.

Results

Overall, 182, 24, 47, and 36 tumors were classified as Hormonal, HER2, Dual, and TN subtypes, respectively. Molecular profiles of tumor aggressiveness and the tumor SUV revealed a gradual increase from the Hormonal to the TN type. The tumor SUV was significantly correlated with tumor size, expression levels of p53, Ki-67, and EGFR, and nuclear grade (all p < 0.001). In contrast, the tumor SUV was negatively correlated with the expression of estrogen receptors (r = − 0.234, p < 0.001) and progesterone receptors (r = − 0.220, p < 0.001). Multiple linear regression analysis revealed that histopathologic markers explained tumor glucose metabolism (adjusted R-squared value 0.238, p < 0.001). Tumor metabolism can thus help define breast cancer subtypes with aggressive/adverse prognostic features.

Conclusions

Metabolic activity measured using FDG PET/CT was significantly correlated with the molecular alteration profiles of breast cancer assessed using immunohistochemical analysis. Combining molecular markers and metabolic information may aid in the recognition and understanding of tumor aggressiveness in breast cancer and be helpful as a prognostic marker.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40644-021-00424-4.

Potentiating Therapeutic Effects of Epidermal Growth Factor Receptor Inhibition in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is a subset of breast cancer with aggressive characteristics and few therapeutic options. The lack of an appropriate therapeutic target is a challenging issue in treating TNBC. Although a high level expression of epidermal growth factor receptor (EGFR) has been associated with a poor prognosis among patients with TNBC, targeted anti-EGFR therapies have demonstrated limited efficacy for TNBC treatment in both clinical and preclinical settings. However, with the advantage of a number of clinically approved EGFR inhibitors (EGFRis), combination strategies have been explored as a promising approach to overcome the intrinsic resistance of TNBC to EGFRis. In this review, we analyzed the literature on the combination of EGFRis with other molecularly targeted therapeutics or conventional chemotherapeutics to understand the current knowledge and to provide potential therapeutic options for TNBC treatment.

Rab25-Mediated EGFR Recycling Causes Tumor Acquired Radioresistance

Tumor acquired radioresistance remains as the major limit in cancer radiotherapy (RT). Rab25, a receptor recycling protein, has been reported to be enhanced in tumors with aggressive phenotype and chemotherapy resistance. In this study, elevated Rab25 expression was identified in an array of radioresistant human cancer cell lines, in vivo radioresistant xenograft tumors. Clinical investigation confirmed that Rab25 expression was also associated with a worse prognosis in patients with lung adenocarcinoma (LUAD) and nasopharyngeal carcinoma (NPC). Enhanced activities of EGFR were observed in both NPC and LUAD radioresistant cells. Rab25 interacts with EGFR to enhance EGFR recycling to cell surface and to decrease degradation in cytoplasm. Inhibition of Rab25 showed synergized radiosensitivity with reduced aggressive phenotype. This study provides the clinical and experimental evidence that Rab25 is a potential therapeutic target to alleviate the hyperactive EGFR signaling and to prevent RT-acquired tumor resistance in patients with LUAD and NPC.

Progress in triple negative breast carcinoma pathophysiology: Potential therapeutic targets

Triple-negative breast carcinoma (TNBC) is a subtype of breast carcinoma defined by negativity for estrogen receptor (ER) or progesterone receptor (PR) by immunohistochemical analysis and negativity for human epidermal growth factor receptor (Her2) by immunohistochemistry or in situ hybridization. TNBC is clinically marked by its high aggressiveness, particularly poor outcomes including a low survival rate, and the lack of specific and effective treatments. Therefore, new potential targets for the treatment of TNBC must be identified. This review summarizes recent evidence supporting novel targets and possible therapeutic regimens in the treatment of TNBC.

Plasma next generation sequencing and droplet digital PCR-based detection of epidermal growth factor receptor (EGFR) mutations in patients with advanced lung cancer treated with subsequent-line osimertinib

BACKGROUND

Gene mutation analysis from plasma circulating tumor DNA (ctDNA) can provide timely information regarding the mechanism of resistance that could translate to personalised treatment. We compared concordance rate of next generation sequencing (NGS) and droplet digital polymerase chain reaction (ddPCR) in the detection of the EGFR activating and T790M mutation from plasma ctDNA with diagnostic tissue biopsy-based assays. The second objective was to test whether putative osimertinib resistance associated mutations were detectable from plasma using NGS.

METHODS

From January 2016 to December 2017, we prospectively collected plasma samples from patients prior to commencement of second- or third-line osimertinib therapy and upon disease progression, in a single tertiary hospital in South Western Sydney, Australia. Amplicon-based NGS and ddPCR assays were used to detect activating epidermal growth factor receptor (EGFR) and T790M mutations in 18 plasma samples from nine patients; all patients were required to have tissue biopsies with known EGFR status.

RESULTS

High concordance of allelic fractions were seen in matched plasma NGS and ddPCR for activating EGFR mutations and T790M mutations (R² = 0.92, P < 0.0001). Using tissue biopsies as reference standard, sensitivity was 100% for NGS and 94% for ddPCR. Several possible osimertinib resistance associated mutations, including PIK3CA, BRAF and TP53 mutations, were detected by NGS in samples upon progression on osimertinib therapy.

CONCLUSION

ddPCR assays for EGFR mutations appear to be as sensitive and highly concordant as amplicon-based NGS. NGS has the ability to detect novel resistance mutations.

Interaction between epidermal growth factor receptor and interleukin-6 receptor in NSCLC progression

Even though the interaction between epithelial growth factor receptor (EGFR) and interleukin-6 receptor (IL-6R) has been found in many tumors, there is a lack of relevant in-depth study of lung cancer. The following study investigates the interaction of EGFR and IL-6R in lung cancer. In the current study, EGFR, IL-6, and glycoprotein 130 (GP130) were highly expressed in non-small cell lung cancer (NSCLC) tissue samples and were associated with clinicopathological features and poor prognosis of patients with NSCLC. Furthermore, the effect of EGF and IL-6 on biological behavior of lung cancer cells (cell proliferation, invasion, cycle, and apoptosis) and the expression of EGFR, GP130, p-protein kinase B (p-AKT), and p-p44/42 mitogen-activated protein kinase (p-p44/42 MAPK) was significantly stronger compared with other treatment groups (all P < 0.05). These results suggest that EGFR and IL-6R have synergistic effects on NSCLC progression. This could help to solve the problem of EGFR inhibitors in the treatment of lung cancer resistance and improve the efficacy of current treatment for lung cancer through a combination of EGFR and IL-6R signaling pathways.

A combination of p53-activating APR-246 and phosphatidylserine-targeting antibody potently inhibits tumor development in hormone-dependent mutant p53-expressing breast cancer xenografts

Background

Between 30 and 40% of human breast cancers express a defective tumor suppressor p53 gene. Wild-type p53 tumor suppressor protein promotes cell-cycle arrest and apoptosis and inhibits vascular endothelial growth factor-dependent angiogenesis, whereas mutant p53 protein (mtp53) lacks these functions, resulting in tumor cell survival and metastasis. Restoration of p53 function is therefore a promising drug-targeted strategy for combating mtp53-expressing breast cancer.

Methods

In this study, we sought to determine whether administration of APR-246, a small-molecule drug that restores p53 function, in combination with 2aG4, an antibody that targets phosphatidylserine residues on tumor blood vessels and disrupts tumor vasculature, effectively inhibits advanced hormone-dependent breast cancer tumor growth.

Results

APR-246 reduced cell viability in mtp53-expressing BT-474 and T47-D human breast cancer cells in vitro, and significantly induced apoptosis in a dose-dependent manner. However, APR-246 did not reduce cell viability in MCF-7 breast cancer cells, which express wild-type p53. We next examined APR-246's anti-tumor effects in vivo using BT-474 and T47-D tumor xenografts established in female nude mice. Tumor-bearing mice were treated with APR-246 and/or 2aG4 and tumor volume followed over time. Tumor growth was more effectively suppressed by combination treatment than by either agent alone, and combination therapy completely eradicated some tumors. Immunohistochemistry analysis of tumor tissue sections demonstrated that combination therapy more effectively induced apoptosis and reduced cell proliferation in tumor xenografts than either agent alone. Importantly, combination therapy dramatically reduced the density of blood vessels, which serve as the major route for tumor metastasis, in tumor xenografts compared with either agent alone.

Conclusion

Based on our findings, we contend that breast tumor growth might effectively be controlled by simultaneous targeting of mtp53 protein and tumor blood vessels in mtp53-expressing cancers.

Tumor suppressor protein p53 exerts negative transcriptional regulation on human sodium iodide symporter gene expression in breast cancer

PURPOSE

Aberrant expression of human sodium iodide symporter (NIS) in breast cancer (BC) is well documented but the transcription factors (TF) regulating its aberrant expression is poorly known. We identify the presence of three p53 binding sites on the human NIS promoter sequence by conducting genome-wide TF analysis, and further investigate their regulatory role.

METHODS

The differences in transcription and translation were measured by real-time PCR, luciferase reporter assay, site-directed mutagenesis, in vivo optical imaging, and chromatin immunoprecipitation. The relation of NIS and p53 in clinical samples was judged by TCGA data analysis and immunohistochemistry.

RESULTS

Overexpression of wild-type p53 as a transgene or pharmacological activation by doxorubicin drug treatment shows significant suppression of NIS transcription in multiple BC cell types which also results in lowered NIS protein content and cellular iodide intake. NIS repression by activated p53 is further confirmed by non-invasive bioluminescence imaging in live cell and orthotropic tumor model. Abrogation of p53-binding sites by directional mutagenesis confirms reversal of transcriptional activity in wild-type p53-positive BC cells. We also observe direct binding of p53 to these sites on the human NIS promoter. Importantly, TCGA data analysis of NIS and p53 co-expression registers an inverse relationship between the two candidates.

CONCLUSION

Our data for the first time highlight the role of p53 as a negative regulator of functional NIS expression in BC, where the latter is a potential targeted radioiodine therapy candidate. Thus, the study provides an important insight into prospective clinical application of this approach that may significantly impact the patient with mutant versus wild-type p53 profile.

Enhancement of Proliferation and Invasion of Gastric Cancer Cell by KDM5C Via Decrease in p53 Expression

Gastric cancer is a malignancy with high incidence and the second leading cause of cancer death worldwide. Development of efficient therapies against gastric cancer is urgent. Until now, the mechanisms of gastric cancer genesis remain elusive. The KDM5C is a histone demethylase that promotes cancer cell growth and is enriched in drug-resistant cancer cells. But the pathogenic breadth and mechanistic aspects of this effect relative to gastric cancer have not been defined. In present study, we found that KDM5C was overexpressed in gastric cancer cell lines and gastric cancer tissues but not in normal gastric tissues. The proliferation and invasive potential of gastric cancer cells was significantly increased by ectopic expression of KDM5C. Contrarily, RNA interference targeting KDM5C in gastric cancer cells significantly decreased the proliferation and invasive potential of cells. Moreover, we also found that the expression of p53 was modulated by KDM5C. Cells with overexpression of KDM5C exhibited greatly decreased p53 expression, whereas silencing of KDM5C expression dramatically increased p53 expression at both the messenger RNA and protein levels. Inhibition of p53 by small-interfering RNA reversed the shKDM5C-induced proliferation and invasion. Our results collectively suggested that KDM5C played a role in gastric cancer cells proliferation and invasion, which may be partly associated with the p53 expression.

Novel insight into triple-negative breast cancers, the emerging role of angiogenesis, and antiangiogenic therapy

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumours characterised by lack of expression of oestrogen-, progesterone- and human epidermal growth factor receptors. TNBC, which represents approximately 15% of all mammary tumours, has a poor prognosis because of an aggressive behaviour and the lack of specific treatment. Accordingly, TNBC has become a major focus of research into breast cancer and is now classified into several molecular subtypes, each with a different prognosis. Pathological angiogenesis occurs at a late stage in the proliferation of TNBC and is associated with invasion and metastasis; there is an association with metabolic syndrome. Semaphorins are a versatile family of proteins with multiple roles in angiogenesis, tumour growth and metastasis and may represent a clinically useful focus for therapeutic targeting in this type of breast cancer. Another important field of investigation into the control of pathological angiogenesis is related to the expression of noncoding RNA (ncRNA) – these molecules can be considered as a therapeutic target or as a biomarker. Several molecular agents for intervening in the activity of different signalling pathways are being explored in TNBC, but none has so far proved effective in clinical trials and the disease continues to pose a defining challenge for clinical management as well as innovative cancer research.

Alcohol promotes migration and invasion of triple-negative breast cancer cells through activation of p38 MAPK and JNK

Although alcohol is an established breast cancer risk factor, the underlying mechanisms remain unclear. Previous studies examined the general association between alcohol consumption and breast cancer risk; however, the risk for different breast cancer subtypes has been rarely reported. Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking hormone receptors and HER2 expression, and having poor prognosis. Understanding the molecular mechanisms of TNBC etiology remains a significant challenge. In this study, we investigated cellular responses to alcohol in two TNBC cell lines, MDA-MB-231 and MDA-MB-468. Our results showed that alcohol at low concentrations (0.025-0.1% v/v) induced cell proliferation, migration, and invasion in 1% FBS-containing medium. Molecular analysis indicated that these phenotypic changes were associated with alcohol-induced reactive oxygen species production and increased p38 and JNK phosphorylation. Likewise, p38 or JNK inhibition attenuated alcohol-induced cell migration and invasion. We revealed that alcohol treatment activated/phosphorylated NF-κB regulators and increased transcription of NF-κB-targeted genes. While examining the role of acetaldehyde, the major alcohol metabolite, in alcohol-associated responses in TNBC cells, we saw that acetaldehyde induced cell migration, invasion, and increased phospho-p38, phospho-JNK, and phospho-IκBα in a pattern similar to alcohol treatment. Taken together, we established that alcohol promotes TNBC cell proliferation, migration, and invasion in vitro. The underlying mechanisms involve the induction of oxidative stress and the activation of NF-κB signaling. In particular, the activation of p38 and JNK plays a pivotal role in alcohol-induced cellular responses. These results will advance our understanding of alcohol-mediated development and promotion of TNBC. © 2016 Wiley Periodicals, Inc.

Histone deacetylase inhibitors suppress mutant p53 transcription via HDAC8/YY1 signals in triple negative breast cancer cells

There is an urgent need to investigate the potential targeted therapy approach for triple-negative breast cancer (TNBC). Our present study reveals that histone deacetylase inhibitors (HDACIs) suberoyl anilide hydroxamic acid (SAHA) and sodium butyrate (NaB) significantly inhibit cell proliferation, arrest cell cycle at G0/G1 phase, and induce mitochondrial related apoptosis of TNBC cells. Further, SAHA and NaB decrease the phosphorylation, protein and mRNA levels of mutant p53 (mtp53) in TNBC cells. While SAHA or NaB has no similar inhibition effect on wild type p53 (wtp53). The inhibition apparently occurs at the level of transcription because the down regulation of precursor p53 transcription is much more rapid (less than 2h) and sharp than that of mature p53. The knockdown of HDAC8, while not HDAC6, inhibits the transcription of mtp53 in TNBC cells. The luciferase assay and ChIP analysis reveal that both SAHA and NaB can reduce the binding of transcription factor Yin Yang 1 (YY1) with the -102 to -96 position of human p53 promoter. Knockdown of YY1 also significantly inhibits the transcription of mtp53 in TNBC cells. Further, SAHA and NaB can inhibit the association of HDAC8 and YY1, increase acetylation of residues 170-200 of YY1, then decrease its transcription activities, and finally suppress YY1 induced p53 transcription. Together, our data establish that SAHA and NaB can be considered as drug candidates for TNBC patients, and HDAC8/YY1/mtp53 signals act as an important target for TNBC treatment.

Quantum dot-based in situ simultaneous molecular imaging and quantitative analysis of EGFR and collagen IV and identification of their prognostic value in triple-negative breast cancer

Triple-negative breast cancer (TNBC) is a unique breast cancer subtype with high heterogeneity and poor prognosis. Currently, the treatment effect of TNBC has reached a bottleneck, rendering new breakthroughs difficult. Cancer invasion is not an entirely cell-autonomous process, requiring the cells to transmigrate across the surrounding extracellular matrix (ECM) barriers. Developing a new system that integrates key constituents in the tumor microenvironment with pivotal cancer cell molecules is essential for the in-depth investigation of the mechanism of invasion in TNBC. We describe a computer-aided algorithm developed using quantum dot (QD)-based multiplex molecular imaging of TNBC tissues. We performed in situ simultaneous imaging and quantitative detection of epidermal growth factor receptor (EGFR), expressed in the TNBC cell membrane, and collagen IV, the major ECM constituent; calculated the EGFR/collagen IV ratio; and investigated the prognostic value of the EGFR/collagen IV ratio in TNBC. We simultaneously imaged and quantitatively detected EGFR and collagen IV in the TNBC samples. In all patients, quantitative determination showed a statistically significant negative correlation between EGFR and collagen IV. The 5-year disease-free survival (5-DFS) of the high and low EGFR/collagen IV ratio subgroups was significantly different. The EGFR/collagen IV ratio was predictive and was an independent prognostic indicator in TNBC. Compared with EGFR expression, the EGFR/collagen IV ratio had a greater prognostic value for 5-DFS. Our findings open up a new avenue for predicting the clinical outcome in TNBC from the perspective of integrating molecules expressed in both cancer cells and the ECM.

Perspectives on Epidermal Growth Factor Receptor Regulation in Triple-Negative Breast Cancer: Ligand-Mediated Mechanisms of Receptor Regulation and Potential for Clinical Targeting

Currently, there are no effective targeted therapies for triple-negative breast cancer (TNBC) indicating a critical unmet need for breast cancer patients. Tumors that fall into the triple-negative category of breast cancers do not respond to the targeted therapies currently approved for breast cancer treatment, such as endocrine therapy (tamoxifen, aromatase inhibitors) or human epidermal growth factor receptor-2 (HER2) inhibitors (trastuzumab, lapatinib), because these tumors lack the most common breast cancer markers: estrogen receptor, progesterone receptor, and HER2. While many patients with TNBC respond to chemotherapy, subsets of patients fare poorly and relapse very quickly. Studies indicate that epidermal growth factor receptor (EGFR) is frequently overrepresented in TNBC (>50%), suggesting EGFR could be used as a biomarker and target in breast cancer. While it is clear that this growth factor receptor plays an integral role in TNBC, little is known about the mechanisms of sustained EGFR activation and how to target this protein despite availability of EGFR-targeted inhibitors, suggesting that our understanding of EGFR deregulation in TNBC is incomplete.

Knockdown of metadherin inhibits angiogenesis in breast cancer

Angiogenesis plays an important role in cancer growth, invasion and metastasis. It has been confirmed that metadherin (MTDH) is associated with angiogenesis. However, the detailed mechanism of MTDH on angiogenesis has not yet been reported. In this study, we demonstrate the anti-angiogenic function of MTDH in breast cancer. With RNA interference strategies, we found that knockdown of MTDH inhibits cellular angiogenesis both in vitro and ex vivo. Furthermore, we revealed that ERK1/2 pathway is involved in the anti-angiogenic function of MTDH, and the function can be partially reversed via upregulation of microRNA-21 (miR-21). In conclusion, knockdown of MTDH can inhibit angiogenesis in breast cancer. These results show that MTDH is a viable therapeutic target for anti-angiogenesis in breast cancer.

JARID1B modulates lung cancer cell proliferation and invasion by regulating p53 expression

Although three therapeutic modalities (surgical resection, chemotherapy, and radiotherapy) have been established, long-term survival for lung cancer patients is still generally poor. Until now, the mechanisms of lung cancer genesis remain elusive. The JARID1B is a histone demethylase that has been proposed as oncogene in several types of human cancer, but its clinical significance and functional role in human non-small cell lung cancer (NSCLC) remain unclear. In present study, we found that JARID1B was overexpressed in lung cancer cell lines and lung cancer tissues but not in normal lung tissues. The proliferation and invasive potential of lung cancer cells was significantly increased by ectopic expression of JARID1B. Contrarily, RNA interference targeting JARID1B in lung cancer cells significantly decreased the proliferation and invasive potential of cells. Moreover, we also found that the expression of p53 was modulated by JARID1B. Overexpressed JARID1B cell exhibited greatly decreased p53 expression, whereas silencing of JARID1B expression dramatically increased p53 expression at both the messenger RNA (mRNA) and protein levels. Inhibition of p53 by small interfering RNA (siRNA) reversed the shJARID1B-induced suppression of proliferation and invasion. Our results collectively suggested that JARID1B expressed in lung cancer played a role in lung cancer cells proliferation and invasion, which may be partly associated with the p53 expression.

Lipid nanocarriers of a lipid-conjugated estrogenic derivative inhibit tumor growth and enhance cisplatin activity against triple-negative breast cancer: pharmacokinetic and efficacy evaluation

Breast cancer is the leading cause of malignancies among women globally. The triple negative breast cancer (TNBC) subtype is the most difficult to treat and accounts for 15% of all cases. Targeted therapies have been developed for TNBC but come short of clinical translation due to acquired tumor resistance. An effective therapy against TNBC must combine properties of target specificity, efficient tumor killing, and translational relevance. The objective of this study was to formulate a nontoxic, cationic, lipid-conjugated estrogenic derivative (ESC8), with demonstrated anticancer activity, for oral delivery in mice bearing triple negative breast cancer (TNBC) as xenograft tumors. The in vitro cell viability, Caco-2 permeability, and cell cycle dynamics of ESC8-treated TNBC cells were investigated. ESC8 was formulated as liposomes, solid lipid nanoparticles (SLNs), and nanostructured lipid carriers (NLCs) and characterized for size, zeta potential, entrapment efficiency, size stability, and tumor biodistribution. Pharmacokinetic modeling of plasma concentration-time course data was carried out following intravenous and oral administration in Sprague-Dawley rats. In vivo efficacy investigation of ESC8-SLNC was carried out in Nu/Nu mice bearing MDA-MB-231 TNBC as xenograft tumors, and the molecular dynamics modulating tumor growth inhibition was analyzed by Western blot. In vitro ESC8 inhibited TNBC and non-TNBC cell viability with IC50 ranging from 1.81 to 3.33 μM. ESC8 was superior to tamoxifen and Cisplatin in inhibiting MDA-MB-231 cell viability; and at 2.0 μM ESC8 enhanced Cisplatin cytotoxicity 16-fold. Intravenous ESC8 (2.0 mg/kg) was eliminated at a rate of 0.048 ± 0.01 h(-1) with a half-life of 14.63 ± 2.95 h in rats. ESC8 was orally bioavailable (47.03%) as solid lipid nanoparticles (ESC8-SLN). ESC8-SLN (10 mg/kg/day, ×14 days, p.o.) inhibited breast tumor growth by 74% (P < 0.0001 vs control) in mice bearing MDA-MB-231 cells as xenografts; and when given in combination with Cisplatin (2.0 mg/kg/biweekly, ×2 weeks, IV), tumor growth was inhibited by 87% (P = 0.0002, vs ESC8-SLN; 10 mg/kg/day, ×14 days, p.o). ESC8-SLN tumor growth inhibition was associated with increased expression of p21 and Caspase-9; as well as by inhibition of EGFR, Slug, p-Akt1, Vimentin, NFkβ, and IKKγ. These results show the promise of ESC8 as an oral adjuvant or neoadjuvant against triple negative breast cancer.

Overexpressed ubiquitin ligase Cullin7 in breast cancer promotes cell proliferation and invasion via down-regulating p53

Ubiquitin ligase Cullin7 has been identified as an oncogene in some malignant diseases such as choriocarcinoma and neuroblastoma. However, the role of Cullin7 in breast cancer carcinogenesis remains unclear. In this study, we compared Cullin7 protein levels in breast cancer tissues with normal breast tissues and identified significantly higher expression of Cullin7 protein in breast cancer specimens. By overexpressing Cullin7 in breast cancer cells HCC1937, we found that Cullin7 could promote cell growth and invasion in vitro. In contrast, the cell growth and invasion was inhibited by silencing Cullin7 in breast cancer cell BT474. Moreover, we demonstrated that Cullin7 promoted breast cancer cell proliferation and invasion via down-regulating p53 expression. Thus, our study provided evidence that Cullin7 functions as a novel oncogene in breast cancer and may be a potential therapeutic target for breast cancer management.

The impact of p53 in predicting clinical outcome of breast cancer patients with visceral metastasis

In the study, we analyzed role of p53 in predicting outcome in visceral metastasis breast cancer (VMBC) patients. 97 consecutive VMBC patients were studied. P53 positivity rate was 29.9%. In the p53-negative group, median disease free survival (DFS), and time from primary breast cancer diagnosis to death (OS1), time from metastases to death (OS2) were 25, 42.5, and 13.5 months, respectively. In the p53-positive group, they were 10, 22, and 8 months, respectively. Statistically significant differences in DFS and OS1 were detected between the p53-negative and p53-positive subtypes. However, p53 appears to have no influence on OS2. In Cox regression analysis, p53 expression and TNM stage were predictive factors of DFS. In the multivariate analysis, p53 expression and the duration of DFS correlated with OS1, but not for OS2. Taken together, our data indicate p53 showing predicting role in OS1 for VMBC, but not for OS2.