Prognostic factors in soft tissue sarcomaTissue microarray for immunostaining, the importance of whole-tumor sections and time-dependence

Sensitivity and Resistance of Oncogenic RAS-Driven Tumors to Dual MEK and ERK Inhibition

Simple Summary

Mutations in RAS-family genes frequently cause different types of human cancers. Inhibitors of the MEK (mitogen-activated protein kinase) and ERK (extracellular signal-regulated kinase) protein kinases that function downstream of RAS proteins have shown some clinical benefits when used for the treatment of these cancers, but drug resistance frequently emerges. Here we show that combined treatment with MEK and ERK inhibitors blocks the emergence of resistance to either drug alone. However, if cancer cells have already developed resistance to MEK inhibitors or to ERK inhibitors, the combined therapy is frequently ineffective. These findings imply that these inhibitors should be used together for cancer therapy. We also show that drug resistance involves complex patterns of rewiring of cellular kinase signaling networks that do not overlap between each different cancer cell line. Nonetheless, we show that MAP4K4 is required for efficient cell proliferation in several different MEK/ERK inhibitor resistant cancer cell lines, uncovering a potential new therapeutic target.

Abstract

Oncogenic mutations in RAS family genes arise frequently in metastatic human cancers. Here we developed new mouse and cellular models of oncogenic Hras^G12V-driven undifferentiated pleomorphic sarcoma metastasis and of Kras^G12D-driven pancreatic ductal adenocarcinoma metastasis. Through analyses of these cells and of human oncogenic KRAS-, NRAS- and BRAF-driven cancer cell lines we identified that resistance to single MEK inhibitor and ERK inhibitor treatments arise rapidly but combination therapy completely blocks the emergence of resistance. The prior evolution of resistance to either single agent frequently leads to resistance to dual treatment. Dual MEK inhibitor plus ERK inhibitor therapy shows anti-tumor efficacy in an Hras^G12V-driven autochthonous sarcoma model but features of drug resistance in vivo were also evident. Array-based kinome activity profiling revealed an absence of common patterns of signaling rewiring in single or double MEK and ERK inhibitor resistant cells, showing that the development of resistance to downstream signaling inhibition in oncogenic RAS-driven tumors represents a heterogeneous process. Nonetheless, in some single and double MEK and ERK inhibitor resistant cell lines we identified newly acquired drug sensitivities. These may represent additional therapeutic targets in oncogenic RAS-driven tumors and provide general proof-of-principle that therapeutic vulnerabilities of drug resistant cells can be identified.

Soft tissue sarcoma: DWI and DCE-MRI parameters correlate with Ki-67 labeling index

OBJECTIVES

To examine the correlation of diffusion-weighted and dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters with Ki-67 labeling index (LI) in soft tissue sarcoma (STS).

METHODS

The institutional review board approved this retrospective study, and the requirement for informed consent was waived. Thirty-six patients with STS who underwent 3.0-T MRI, including diffusion-weighted and dynamic contrast-enhanced MRI, between July 2011 and February 2018, were included in this study. The mean and minimum apparent diffusion coefficients (ADCs) (ADC_mean and ADC_min, respectively), volume transfer constant, reflux rate, and volume fraction of the extravascular extracellular matrix of each lesion were independently analyzed by two readers. Their relationship with the Ki-67 LI was examined using Spearman's correlation analyses. Differences between low- and high-proliferation groups based on Ki-67 LI were evaluated statistically. Optimal cut-off points were determined using the area under the curve analysis for significant parameters. Interobserver agreement was assessed with the intraclass correlation coefficient.

RESULTS

ADC_mean (ρ = - 0.333, p = 0.047) was significantly and inversely correlated with Ki-67 LI. The high-proliferation group showed a significantly lower ADC_mean than did the low-proliferation group (median, 1.08 vs. 1.20; p = 0.048). When a cut-off ADC_mean value of 1.16 × 10^-3 mm²/s was used, the sensitivity, specificity, and area under the curve for differentiating low- and high-proliferation groups were 75.0%, 60.0%, and 0.712, respectively. Interobserver agreements between the two readers were almost perfect for all parameters.

CONCLUSIONS

ADC_mean was correlated with Ki-67 LI and could help differentiate between STS with low and high proliferation potential.

KEY POINTS

• ADC _meanwas significantly and inversely correlated with Ki-67 labeling index in soft tissue sarcoma. • In the high-proliferation group, ADC _meanvalues were significantly lower than those of the low-proliferation group.

Prognostic value of proliferation in pleomorphic soft tissue sarcomas: a new look at an old measure

Though proliferation has repeatedly shown a prognostic role in sarcomas, it has not reached clinical application. We performed a comprehensive evaluation of the prognostic role of 5 proliferation measures in a large series of soft tissue sarcomas of the extremities and the trunk wall. One hundred ninety-six primary soft tissue sarcomas of the extremities and the trunk wall were subjected to DNA flow cytometry for quantification of S-phase fraction and to immunohistochemical evaluation of Ki-67, Top2a, p21, and p27Kip1. In univariate analysis, positive expression of Ki-67 (hazard ratio = 4.5, CI = 1.6-12.1), Top2a (hazard ratio = 2.2, CI = 1.2-3.5) and high S-phase fraction (hazard ratio = 1.8, CI = 1.2-3.7) significantly correlated with risk for metastasis. When combined with currently used prognostic factors, Ki-67, S-phase fraction and Top2a fraction contributed to refined identification of prognostic risk groups. Proliferation, as assessed by expression of Ki-67 and Top2a and evaluation of S-phase fraction and applied to statistical decision-tree models, provides prognostic information in soft tissue sarcomas of the extremity and trunk wall. Though proliferation contributes independently to currently applied prognosticators, its role is particularly strong when few other factors are available, which suggests a role in preoperative decision-making related to identification of high-risk individuals who would benefit from neoadjuvant therapy.

MMP-7 as a prognostic marker in colorectal cancer

Matrix metalloproteinase-7 is capable of degrading many extracellular matrix proteins and cellular adhesions. In many malignancies, it is overexpressed, and it plays a role in cancer progression by enhancing tumor invasion and thereby metastatic potential. The purpose of this study was to evaluate the association between MMP-7 tissue expression and prognosis in colorectal cancer. From 623 patients who underwent surgery for colorectal cancer, surgical specimens were collected into tissue array blocks and stained by immunohistochemistry for MMP-7. Specimens from 545 patients were suitable for analysis. In specimens from 105 patients (19.3%), MMP-7 scored as high; in 103 (18.9%), as moderate; and in 134 (24.9%), as mild. In 203 cases (37.2%), immunoreactivity was negative. A significant correlation appeared between MMP-7 immunoexpression and tumor differentiation. High MMP-7 positivity associated with poor prognosis during a 5-year follow-up. During longer follow-up, the differences in survival between groups disappeared. MMP-7 is a potential target for tumor therapy, which should be evaluated in clinical trials.

Immunoglobulin G is present in a wide variety of soft tissue tumors and correlates well with proliferation markers and tumor grades

BACKGROUND

The traditional view that immunoglobulin (Ig) is produced only by B lymphocytes has been challenged, because it has been demonstrated that Ig genes and proteins are expressed in epithelial cancer cells. However, whether Ig expression in nonlymphoid cells is limited to epithelial cells is unclear. Because sarcomas differ distinctly from carcinomas in their biologic and clinical features, the authors investigated the question of nonlymphoid IgG expression in soft tissue lesions.

METHODS

Immunohistochemistry, in situ hybridization, and polymerase chain reaction (PCR) were used to demonstrate IgG expression in 80 soft tissue lesions. The correlation between Ig expression and proliferation markers (proliferating cell nuclear antigen [PCNA], Ki-67, and cyclin D1) in sarcomas was investigated by immunohistochemical and statistical analyses.

RESULTS

Igkappa was identified in 97.4% of sarcomas and in 31.7% of benign lesions by immunohistochemistry. The difference was statistically significant (P < .01). Messenger RNA from the IgG1 heavy-chain constant region was also detected by in situ hybridization. Variable-diversity-joining recombination sequences of both heavy and light chains were obtained by PCR and sequencing. Moreover, the labeling index of PCNA, Ki-67, and cyclin D1 was much higher in sarcomas with high Igkappa expression than in sarcomas with low Igkappa expression (P < .01 for PCNA and cyclin D1; P < .001 for Ki-67). There were more grade 3 sarcomas with high Igkappa expression compared with grade 1 and 2 sarcomas (P < .05).

CONCLUSIONS

IgG was identified in a wide variety of soft tissue tumors and correlated well with proliferation markers and tumor grades. IgG may be a useful marker for cell proliferation in sarcomas.

CA125 expression pattern, prognosis and correlation with serum CA125 in ovarian tumor patients. From The Danish "MALOVA" Ovarian Cancer Study

OBJECTIVES

To determine the CA125 tissue expression levels in borderline and invasive epithelial ovarian tumor tissues. Secondly, to evaluate whether CA125 tissue expression levels correlate with clinico-pathological parameters and serum CA125 levels and finally to investigate the prognostic value of tissue CA125 expression levels in ovarian cancer (OC) patients.

METHODS

We designed tissue arrays (TA) and analyzed the CA125 expression in tissues from 778 Danish women with an ovarian tumor. Furthermore, corresponding preoperative blood samples obtained before surgery were collected from 382 women with OC.

RESULTS

Significantly more CA125 expression positive tumors (no expression vs. expression) were found in the serous subtype compared to the percentage of positive tumors in mucinous, endometroid and other subtypes for patients both with borderline ovarian tumors and with OC (p<0.00001, p<0.00001). Similarly, a positive significant correlation was found between elevated serum CA125 levels and elevated levels of CA125 tissue expression (N=382 stage I-IV OC, Spearman rho=0.31, p<0.0001) (N=206 stage III OC, Spearman rho=0.30, p<0.0001). We found a significantly shorter survival for stage III/IV OC patients with no CA125 tissue expression compared to stage III/IV OC patients with positive CA125 tissue expression (p=0.0003).

CONCLUSION

Our finding that tissue CA125 expression was lacking in late stage primary OC tumor of Danish women with poor survival may be of value in selecting patients as eligible candidates for individually based treatments.